1
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Venanzi NE, Basciu A, Vargiu AV, Kiparissides A, Dalby PA, Dikicioglu D. Machine Learning Integrating Protein Structure, Sequence, and Dynamics to Predict the Enzyme Activity of Bovine Enterokinase Variants. J Chem Inf Model 2024; 64:2681-2694. [PMID: 38386417 PMCID: PMC11005043 DOI: 10.1021/acs.jcim.3c00999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
Despite recent advances in computational protein science, the dynamic behavior of proteins, which directly governs their biological activity, cannot be gleaned from sequence information alone. To overcome this challenge, we propose a framework that integrates the peptide sequence, protein structure, and protein dynamics descriptors into machine learning algorithms to enhance their predictive capabilities and achieve improved prediction of the protein variant function. The resulting machine learning pipeline integrates traditional sequence and structure information with molecular dynamics simulation data to predict the effects of multiple point mutations on the fold improvement of the activity of bovine enterokinase variants. This study highlights how the combination of structural and dynamic data can provide predictive insights into protein functionality and address protein engineering challenges in industrial contexts.
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Affiliation(s)
| | - Andrea Basciu
- Department
of Physics, University of Cagliari, Cittadella
Universitaria, I-09042 Monserrato, Cagliari, Italy
| | - Attilio Vittorio Vargiu
- Department
of Physics, University of Cagliari, Cittadella
Universitaria, I-09042 Monserrato, Cagliari, Italy
| | - Alexandros Kiparissides
- Department
of Biochemical Engineering, University College
London, Gower Street, WC1E 6BT London, U.K.
- Department
of Chemical Engineering, Aristotle University
of Thessaloniki, 54 124 Thessaloniki, Greece
| | - Paul A. Dalby
- Department
of Biochemical Engineering, University College
London, Gower Street, WC1E 6BT London, U.K.
| | - Duygu Dikicioglu
- Department
of Biochemical Engineering, University College
London, Gower Street, WC1E 6BT London, U.K.
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2
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Spiteri VA, Doutch J, Rambo RP, Bhatt JS, Gor J, Dalby PA, Perkins SJ. Using atomistic solution scattering modelling to elucidate the role of the Fc glycans in human IgG4. PLoS One 2024; 19:e0300964. [PMID: 38557973 PMCID: PMC10984405 DOI: 10.1371/journal.pone.0300964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
Human immunoglobulin G (IgG) exists as four subclasses IgG1-4, each of which has two Fab subunits joined by two hinges to a Fc subunit. IgG4 has the shortest hinge with 12 residues. The Fc subunit has two glycan chains, but the importance of glycosylation is not fully understood in IgG4. Here, to evaluate the stability and structure of non-glycosylated IgG4, we performed a multidisciplinary structural study of glycosylated and deglycosylated human IgG4 A33 for comparison with our similar study of human IgG1 A33. After deglycosylation, IgG4 was found to be monomeric by analytical ultracentrifugation; its sedimentation coefficient of 6.52 S was reduced by 0.27 S in reflection of its lower mass. X-ray and neutron solution scattering showed that the overall Guinier radius of gyration RG and its cross-sectional values after deglycosylation were almost unchanged. In the P(r) distance distribution curves, the two M1 and M2 peaks that monitor the two most common distances within IgG4 were unchanged following deglycosylation. Further insight from Monte Carlo simulations for glycosylated and deglycosylated IgG4 came from 111,382 and 117,135 possible structures respectively. Their comparison to the X-ray and neutron scattering curves identified several hundred best-fit models for both forms of IgG4. Principal component analyses showed that glycosylated and deglycosylated IgG4 exhibited different conformations from each other. Within the constraint of unchanged RG and M1-M2 values, the glycosylated IgG4 models showed more restricted Fc conformations compared to deglycosylated IgG4, but no other changes. Kratky plots supported this interpretation of greater disorder upon deglycosylation, also observed in IgG1. Overall, these more variable Fc conformations may demonstrate a generalisable impact of deglycosylation on Fc structures, but with no large conformational changes in IgG4 unlike those seen in IgG1.
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Affiliation(s)
- Valentina A. Spiteri
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - James Doutch
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, United Kingdom
| | - Robert P. Rambo
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire, United Kingdom
| | - Jayesh S. Bhatt
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Jayesh Gor
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Paul A. Dalby
- Department of Biochemical Engineering, University College London, London, United Kingdom
| | - Stephen J. Perkins
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
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3
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Wood V, Kellerman MA, Groves K, Quaglia M, Topp EM, Matejtschuk P, Dalby PA. Investigation of the Solid-State Interactions in Lyophilized Human G-CSF Using Hydrogen-Deuterium Exchange Mass Spectrometry. Mol Pharm 2024; 21:1965-1976. [PMID: 38516985 PMCID: PMC10988552 DOI: 10.1021/acs.molpharmaceut.3c01211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 03/23/2024]
Abstract
Hydrogen/deuterium exchange mass spectrometry (HDX-MS) previously elucidated the interactions between excipients and proteins for liquid granulocyte colony stimulating factor (G-CSF) formulations, confirming predictions made using computational structure docking. More recently, solid-state HDX mass spectrometry (ssHDX-MS) was developed for proteins in the lyophilized state. Deuterium uptake in ssHDX-MS has been shown for various proteins, including monoclonal antibodies, to be highly correlated with storage stability, as measured by protein aggregation and chemical degradation. As G-CSF is known to lose activity through aggregation upon lyophilization, we applied the ssHDX-MS method with peptide mapping to four different lyophilized formulations of G-CSF to compare the impact of three excipients on local structure and exchange dynamics. HDX at 22 °C was confirmed to correlate well with the monomer content remaining after lyophilization and storage at -20 °C, with sucrose providing the greatest protection, and then phenylalanine, mannitol, and no excipient leading to progressively less protection. Storage at 45 °C led to little difference in final monomer content among the formulations, and so there was no discernible relationship with total deuterium uptake on ssHDX. Incubation at 45 °C may have led to a structural conformation and/or aggregation mechanism no longer probed by HDX at 22 °C. Such a conformational change was observed previously at 37 °C for liquid-formulated G-CSF using NMR. Peptide mapping revealed that tolerance to lyophilization and -20 °C storage was linked to increased stability in the small helix, loop AB, helix C, and loop CD. LC-MS HDX and NMR had previously linked loop AB and loop CD to the formation of a native-like state (N*) prior to aggregation in liquid formulations, suggesting a similar structural basis for G-CSF aggregation in the liquid and solid states.
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Affiliation(s)
- Victoria
E. Wood
- Department
of Biochemical Engineering, University College
London, London WC1E 6BT, United
Kingdom
| | - Mark-Adam Kellerman
- Department
of Biochemical Engineering, University College
London, London WC1E 6BT, United
Kingdom
| | - Kate Groves
- LGC, Queens Road, Teddington, Middlesex TQ11 0LY, United Kingdom
| | - Milena Quaglia
- LGC, Queens Road, Teddington, Middlesex TQ11 0LY, United Kingdom
| | - Elizabeth M. Topp
- Department
of Industrial and Molecular Pharmaceutics, College of Pharmacy, and
Davidson School of Chemical Engineering, College of Engineering Purdue University, West Lafayette, Indiana 47907, United States
| | - Paul Matejtschuk
- Standardisation
Science, NIBSC, Medicines & Healthcare
Products Regulatory Agency, South Mimms, Hertfordshire EN6 3QG, United
Kingdom
| | - Paul A. Dalby
- Department
of Biochemical Engineering, University College
London, London WC1E 6BT, United
Kingdom
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4
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Mukhopadhyay A, Karu K, Dalby PA. Two-substrate enzyme engineering using small libraries that combine the substrate preferences from two different variant lineages. Sci Rep 2024; 14:1287. [PMID: 38218974 PMCID: PMC10787763 DOI: 10.1038/s41598-024-51831-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/09/2024] [Indexed: 01/15/2024] Open
Abstract
Improving the range of substrates accepted by enzymes with high catalytic activity remains an important goal for the industrialisation of biocatalysis. Many enzymes catalyse two-substrate reactions which increases the complexity in engineering them for the synthesis of alternative products. Often mutations are found independently that can improve the acceptance of alternatives to each of the two substrates. Ideally, we would be able to combine mutations identified for each of the two alternative substrates, and so reprogramme new enzyme variants that synthesise specific products from their respective two-substrate combinations. However, as we have previously observed for E. coli transketolase, the mutations that improved activity towards aromatic acceptor aldehydes, did not successfully recombine with mutations that switched the donor substrate to pyruvate. This likely results from several active site residues having multiple roles that can affect both of the substrates, as well as structural interactions between the mutations themselves. Here, we have designed small libraries, including both natural and non-natural amino acids, based on the previous mutational sites that impact on acceptance of the two substrates, to achieve up to 630× increases in kcat for the reaction with 3-formylbenzoic acid (3-FBA) and pyruvate. Computational docking was able to determine how the mutations shaped the active site to improve the proximity of the 3-FBA substrate relative to the enamine-TPP intermediate, formed after the initial reaction with pyruvate. This work opens the way for small libraries to rapidly reprogramme enzyme active sites in a plug and play approach to catalyse new combinations of two-substrate reactions.
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Affiliation(s)
- Arka Mukhopadhyay
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Kersti Karu
- Department of Chemistry, UCL, 20 Gordon Street, London, WC1H 0AJ, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
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5
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Uçan D, Hales JE, Aoudjane S, Todd N, Dalby PA. Column-free optical deconvolution of intrinsic fluorescence for a monoclonal antibody and its product-related impurities. J Chromatogr A 2023; 1711:464463. [PMID: 37866332 DOI: 10.1016/j.chroma.2023.464463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
The quantification of monoclonal antibody (mAb) aggregates and fragments using high pressure liquid chromatography-size exclusion chromatography (HPLC-SEC) typically requires off-line measurements that are time-consuming and therefore not compatible with real-time monitoring. However, it has been crucial to manufacturing and process development, and remains the industrial standard in the assessment of product-related impurities. Here we demonstrate that our previously established intrinsic time-resolved fluorescence (TRF) approach can be used to quantify the bioprocess critical quality attribute (CQA) of antibody product purity at various stages of a typical downstream process, with the potential to be developed for in-line bioprocess monitoring. This was directly benchmarked against industry-standard HPLC-SEC. Strong linear correlations were observed between outputs from TRF spectroscopy and HPLC-SEC, for the monomer and aggregate-fragment content, with R2 coefficients of 0.99 and 0.69, respectively. At total protein concentrations above 1.41 mg/mL, HPLC-SEC UV-Vis chromatograms displayed signs of detector saturation which reduced the accuracy of protein quantification, thus requiring additional sample dilution steps. By contrast, TRF spectroscopy increased in accuracy at these concentrations due to higher signal-to-noise ratios. Our approach opens the potential for reducing the time and labour required for validating aggregate content in mAb bioprocess stages from the several hours required for HPLC-SEC to a few minutes per sample.
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Affiliation(s)
- Deniz Uçan
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gower Street, London WC1E 6BT, UK
| | - John E Hales
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gower Street, London WC1E 6BT, UK
| | - Samir Aoudjane
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gower Street, London WC1E 6BT, UK
| | - Nathan Todd
- Cytiva, 5 Harbourgate Business Park, Southampton Road, Portsmouth PO6 4BQ, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gower Street, London WC1E 6BT, UK.
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6
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Shen W, Dalby PA, Guo Z, Li W, Zhu C, Fan D. Residue Effect-Guided Design: Engineering of S. Solfataricus β-Glycosidase to Enhance Its Thermostability and Bioproduction of Ginsenoside Compound K. J Agric Food Chem 2023; 71:16669-16680. [PMID: 37812684 DOI: 10.1021/acs.jafc.3c04575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
β-Glycosidase from Sulfolobus solfataricus (SS-BGL) is a highly effective biocatalyst for the synthesis of compound K (CK) from glycosylated protopanaxadiol ginsenosides. In order to improve the thermal stability of SS-BGL, molecular dynamics simulations were used to determine the residue-level binding energetics of ginsenoside Rd in the SS-BGL-Rd docked complex and to identify the top ten critical contributors. Target sites for mutations were determined using dynamic cross-correlation mapping of residues via the Ohm server to identify networks of distal residues that interact with the key binding residues. Target mutations were determined rationally based on site characteristics. Single mutants and then recombination of top hits led to the two most promising variants SS-BGL-Q96E/N97D/N302D and SS-BGL-Q96E/N97D/N128D/N302D with 2.5-fold and 3.3-fold increased half-lives at 95 °C, respectively. The enzyme activities relative to those of wild-type for ginsenoside conversion were 161 and 116%, respectively..
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Affiliation(s)
- Wenfeng Shen
- Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing, Ministry of Education, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Shaanxi R&D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Biotech. & Biomed. Research Institute, Northwest University, Xi'an 710069, China
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, London WCIE 6BT, U.K
| | - Zheng Guo
- Department of Biological and Chemical Engineering, Faculty of Science and Technology, Aarhus University, Gustav Wied Vej 10, Aarhus 8000, Denmark
| | - Weina Li
- Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing, Ministry of Education, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Shaanxi R&D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Biotech. & Biomed. Research Institute, Northwest University, Xi'an 710069, China
| | - Chenhui Zhu
- Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing, Ministry of Education, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Shaanxi R&D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Biotech. & Biomed. Research Institute, Northwest University, Xi'an 710069, China
| | - Daidi Fan
- Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing, Ministry of Education, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Shaanxi R&D Center of Biomaterials and Fermentation Engineering, School of Chemical Engineering, Northwest University, Xi'an 710069, China
- Biotech. & Biomed. Research Institute, Northwest University, Xi'an 710069, China
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7
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Abstract
Accelerating the scale up of adeno-associated virus (AAV) manufacture is highly desirable to meet the increased demand for gene therapies. However, the development of bioprocesses for AAV gene therapies remains time-consuming and challenging. The quality by design (QbD) approach ensures bioprocess designs that meet the desired product quality and safety profile. Rapid stress tests, developability screens, and scale-down technologies have the potential to streamline AAV product and manufacturing bioprocess development within the QbD framework. Here we review how their successful use for antibody manufacture development is translating to AAV, but also how this will depend critically on improved analytical methods and adaptation of the tools as more understanding is gained on the critical attributes of AAV required for successful therapy.
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Affiliation(s)
- Ziyu Jiang
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, UK.
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8
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Tang J, Zhang C, Castillo NC, Lalaurie CJ, Gao X, Dalby PA, Kozielski F. Crystal structures and molecular dynamics simulations of a humanised antibody fragment at acidic to basic pH. Sci Rep 2023; 13:16281. [PMID: 37770469 PMCID: PMC10539359 DOI: 10.1038/s41598-023-42698-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
Antibody-fragment (Fab) therapy development has the potential to be accelerated by computational modelling and simulations that predict their target binding, stability, formulation, manufacturability, and the impact of further protein engineering. Such approaches are currently predicated on starting with good crystal structures that closely represent those found under the solution conditions to be simulated. A33 Fab, is an undeveloped immunotherapeutic antibody candidate that was targeted to the human A33 antigen homogeneously expressed in 95% cases of primary and metastatic colorectal cancers. It is now used as a very well characterised testing ground for developing analytics, formulation and protein engineering strategies, and to gain a deeper understanding of mechanisms of destabilisation, representative of the wider therapeutic Fab platform. In this article, we report the structure of A33 Fab in two different crystal forms obtained at acidic and basic pH. The structures overlapped with RMSD of 1.33 Å overall, yet only 0.5 Å and 0.76 Å for the variable- and constant regions alone. While most of the differences were within experimental error, the switch linker between the variable and the constant regions showed some small differences between the two pHs. The two structures then enabled a direct evaluation of the impact of initial crystal structure selection on the outcomes of molecular dynamics simulations under different conditions, and their subsequent use for determining best fit solution structures using previously obtained small-angle x-ray scattering (SAXS) data. The differences in the two structures did not have a major impact on MD simulations regardless of the pH, other than a slight persistence of structure affecting the solvent accessibility of one of the predicted APR regions of A33 Fab. Interestingly, despite being obtained at pH 4 and pH 9, the two crystal structures were more similar to the SAXS solution structures obtained at pH 7, than to those at pH 4 or pH 9. Furthermore, the P65 crystal structure from pH 4 was also a better representation of the solution structures at any other pH, than was the P1 structure obtained at pH 9. Thus, while obtained at different pH, the two crystal structures may represent highly (P65) and lesser (P1) populated species that both exist at pH 7 in solution. These results now lay the foundation for confident MD simulations of A33 Fab that rationalise or predict behaviours in a range of conditions.
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Affiliation(s)
- Jiazhi Tang
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Cheng Zhang
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Nuria Codina Castillo
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Christophe J Lalaurie
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Xin Gao
- Division of Biosciences, Department of Structural and Molecular Biology, UCL, London, WC1E 6BT, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
| | - Frank Kozielski
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK.
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9
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Zhang C, Berg A, Joe CCD, Dalby PA, Douglas AD. Lyophilization to enable distribution of ChAdOx1 and ChAdOx2 adenovirus-vectored vaccines without refrigeration. NPJ Vaccines 2023; 8:85. [PMID: 37277337 PMCID: PMC10240132 DOI: 10.1038/s41541-023-00674-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/12/2023] [Indexed: 06/07/2023] Open
Abstract
Distribution of vaccines which require refrigerated or frozen storage can be challenging and expensive. The adenovirus vector platform has been widely used for COVID-19 vaccines while several further candidate vaccines using the platform are in clinical development. In current liquid formulations, adenoviruses require distribution at 2-8 °C. The development of formulations suitable for ambient temperature distribution would be advantageous. Previous peer-reviewed reports of adenovirus lyophilization are relatively limited. Here, we report the development of a formulation and process for lyophilization of simian adenovirus-vectored vaccines based on the ChAdOx1 platform. We describe the iterative selection of excipients using a design of experiments approach, and iterative cycle improvement to achieve both preservation of potency and satisfactory cake appearance. The resulting method achieved in-process infectivity titre loss of around 50%. After drying, there was negligible further loss over a month at 30 °C. Around 30% of the predrying infectivity remained after a month at 45 °C. This performance is likely to be suitable for 'last leg' distribution at ambient temperature. This work may also facilitate the development of other product presentations using dried simian adenovirus-vectored vaccines.
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Affiliation(s)
- Cheng Zhang
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, United Kingdom
| | - Adam Berg
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, OX3 7DQ, Oxford, United Kingdom
| | - Carina C D Joe
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, OX3 7DQ, Oxford, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, United Kingdom
| | - Alexander D Douglas
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, OX3 7DQ, Oxford, United Kingdom.
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10
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Zhang C, Bye JW, Lui LH, Zhang H, Hales J, Brocchini S, Curtis RA, Dalby PA. Enhanced Thermal Stability and Reduced Aggregation in an Antibody Fab Fragment at Elevated Concentrations. Mol Pharm 2023; 20:2650-2661. [PMID: 37040431 PMCID: PMC10155210 DOI: 10.1021/acs.molpharmaceut.3c00081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The aggregation of protein therapeutics such as antibodies remains a major challenge in the biopharmaceutical industry. The present study aimed to characterize the impact of the protein concentration on the mechanisms and potential pathways for aggregation, using the antibody Fab fragment A33 as the model protein. Aggregation kinetics were determined for 0.05 to 100 mg/mL Fab A33, at 65 °C. A surprising trend was observed whereby increasing the concentration decreased the relative aggregation rate, ln(v) (% day-1), from 8.5 at 0.05 mg/mL to 4.4 at 100 mg/mL. The absolute aggregation rate (mol L-1 h-1) increased with the concentration following a rate order of approximately 1 up to a concentration of 25 mg/mL. Above this concentration, there was a transition to an apparently negative rate order of -1.1 up to 100 mg/mL. Several potential mechanisms were examined as possible explanations. A greater apparent conformational stability at 100 mg/mL was observed from an increase in the thermal transition midpoint (Tm) by 7-9 °C, relative to those at 1-4 mg/mL. The associated change in unfolding entropy (△Svh) also increased by 14-18% at 25-100 mg/mL, relative to those at 1-4 mg/mL, indicating reduced conformational flexibility in the native ensemble. Addition of Tween or the crowding agents Ficoll and dextran, showed that neither surface adsorption, diffusion limitations nor simple volume crowding affected the aggregation rate. Fitting of kinetic data to a wide range of mechanistic models implied a reversible two-state conformational switch mechanism from aggregation-prone monomers (N*) into non-aggregating native forms (N) at higher concentrations. kD measurements from DLS data also suggested a weak self-attraction while remaining colloidally stable, consistent with macromolecular self-crowding within weakly associated reversible oligomers. Such a model is also consistent with compaction of the native ensemble observed through changes in Tm and △Svh.
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Affiliation(s)
- Cheng Zhang
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Jordan W Bye
- School of Chemical Engineering and Analytical Science, The University of Manchester, Sackville Street, Manchester M13 9PL, U.K
| | - Lok H Lui
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Hongyu Zhang
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - John Hales
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Steve Brocchini
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, U.K
| | - Robin A Curtis
- School of Chemical Engineering and Analytical Science, The University of Manchester, Sackville Street, Manchester M13 9PL, U.K
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
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11
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Zhang H, Dalby PA. Stability Convergence in Antibody Coformulations. Mol Pharm 2022; 19:4098-4110. [PMID: 36264768 DOI: 10.1021/acs.molpharmaceut.2c00534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Combined administration of antibody therapeutics has proven to be beneficial for patients with cancer or infectious diseases. As a result, there is a growing trend toward multiple antibodies premixed into a single product form and delivered to patients as a fixed-dose coformulation. However, combining antibodies into a single coformulation could be challenging as proteins have the potential to interact and alter their stability and degradation profiles in the mixture, compared to that in isolation. We show that in two specific antibody-antibody coformulations, the more stable antibody component increased the stability of the less stable component, which in return destabilized the more stable component, hence exhibiting an overall convergence of stability in the coformulation.
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Affiliation(s)
- Hongyu Zhang
- Department of Biochemical Engineering, UCL, WC1E 6BTLondon, U.K.,EPSRC Future Targeted Healthcare Manufacturing Hub, UCL, WC1E 6BTLondon, U.K
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, WC1E 6BTLondon, U.K
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12
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Lyu X, Zhao Q, Hui J, Wang T, Lin M, Wang K, Zhang J, Shentu J, Dalby PA, Zhang H, Liu B. The Global Landscape of Approved Antibody Therapies. Antib Ther 2022; 5:233-257. [PMID: 36213257 PMCID: PMC9535261 DOI: 10.1093/abt/tbac021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 11/12/2022] Open
Abstract
Antibody therapies have become an important class of therapeutics in recent years as they have exhibited outstanding efficacy and safety in the treatment of several major diseases including cancers, immune-related diseases, infectious disease and hematological disease. There has been significant progress in the global research and development landscape of antibody therapies in the past decade. In this review, we have collected available data from the Umabs Antibody Therapies Database (Umabs-DB, https://umabs.com) as of 30 June 2022. The Umabs-DB shows that 162 antibody therapies have been approved by at least one regulatory agency in the world, including 122 approvals in the US, followed by 114 in Europe, 82 in Japan and 73 in China, whereas biosimilar, diagnostic and veterinary antibodies are not included in our statistics. Although the US and Europe have been at the leading position for decades, rapid advancement has been witnessed in Japan and China in the past decade. The approved antibody therapies include 115 canonical antibodies, 14 antibody-drug conjugates, 7 bispecific antibodies, 8 antibody fragments, 3 radiolabeled antibodies, 1 antibody-conjugate immunotoxin, 2 immunoconjugates and 12 Fc-Fusion proteins. They have been developed against 91 drug targets, of which PD-1 is the most popular, with 14 approved antibody-based blockades for cancer treatment in the world. This review outlined the global landscape of the approved antibody therapies with respect to the regulation agencies, therapeutic targets and indications, aiming to provide an insight into the trends of the global development of antibody therapies.
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Affiliation(s)
- Xiaochen Lyu
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Qichao Zhao
- Research and development , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Julia Hui
- Big data and discovery , Umabs Therapeutics Inc., Salem, NH 03079 , USA
| | - Tiffany Wang
- Department of Applied math , Harvard College, Cambridge, MA 02138 , USA
| | - Mengyi Lin
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Keying Wang
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Jialing Zhang
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Jiaqian Shentu
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Paul A Dalby
- Department of Biochemical Engineering , University College London, WC1E 6BT, London , UK
| | - Hongyu Zhang
- Big data and bioinformatics , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
- Research and development , Zhanyuan Therapeutics ltd., Hangzhou, Zhejiang, 310000 , China
| | - Bo Liu
- Big data and discovery , Umabs Therapeutics Inc., Salem, NH 03079 , USA
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13
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Kellerman MAW, Almeida T, Rudd TR, Matejtschuk P, Dalby PA. NMR Reveals Functionally Relevant Thermally Induced Structural Changes within the Native Ensemble of G-CSF. Mol Pharm 2022; 19:3242-3255. [PMID: 35948076 PMCID: PMC9449972 DOI: 10.1021/acs.molpharmaceut.2c00398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
Structure–function relationships in proteins refer
to a
trade-off between stability and bioactivity, molded by evolution of
the molecule. Identifying which protein amino acid residues jeopardize
global or local stability for the benefit of bioactivity would reveal
residues pivotal to this structure–function trade-off. Here,
we use 15N–1H heteronuclear single quantum
coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy to
probe the microenvironment and dynamics of residues in granulocyte
colony-stimulating factor (G-CSF) through thermal perturbation. From
this analysis, we identified four residues (G4, A6, T133, and Q134)
that we classed as significant to global stability, given that they
all experienced large environmental and dynamic changes and were closely
correlated to each other in their NMR characteristics. Additionally,
we observe that roughly four structural clusters are subject to localized
conformational changes or partial unfolding prior to global unfolding
at higher temperature. Combining NMR observables with structure relaxation
methods reveals that these structural clusters concentrate around
loop AB (binding site III inclusive). This loop has been previously
implicated in conformational changes that result in an aggregation
prone state of G-CSF. Residues H43, V48, and S63 appear to be pivotal
to an opening motion of loop AB, a change that is possibly also important
for function. Hence, we present here an approach to profiling residues
in order to highlight their potential roles in the two vital characteristics
of proteins: stability and bioactivity.
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Affiliation(s)
- Mark-Adam W Kellerman
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Teresa Almeida
- Medicines & Healthcare Products Regulatory Agency, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Timothy R Rudd
- Medicines & Healthcare Products Regulatory Agency, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom.,Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7BE, United Kingdom
| | - Paul Matejtschuk
- Medicines & Healthcare Products Regulatory Agency, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
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14
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Lalaurie CJ, Splevins A, Barata TS, Bunting KA, Higazi DR, Zloh M, Spiteri VA, Perkins SJ, Dalby PA. Elucidation of critical pH-dependent structural changes in Botulinum Neurotoxin E. J Struct Biol 2022; 214:107876. [PMID: 35738335 DOI: 10.1016/j.jsb.2022.107876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 10/18/2022]
Abstract
Botulinum Neurotoxins (BoNT) are the most potent toxins currently known. However, they also have therapeutic applications for an increasing number of motor related conditions due to their specificity, and low diffusion into the system. Although the start- and end- points for the BoNT mechanism of action are well-studied, a critical step remains poorly understood. It is theorised that BoNTs undergo a pH-triggered conformational shift, activating the neurotoxin by priming it to form a transmembrane (TM) channel. To test this hypothesis, we combined molecular dynamics (MD) simulations and small-angle x-ray scattering (SAXS), revealing a new conformation of serotype E (BoNT/E). This conformation was exclusively observed in simulations below pH 5.5, as determined by principal component analysis (PCA), and its theoretical SAXS profile matched an experimental SAXS profile obtained at pH 4. Additionally, a localised secondary structural change was observed in MD simulations below pH 5.5, in a region previously identified as instrumental for membrane insertion for serotype A (BoNT/A). These changes were found at a critical pH value for BoNTs in vivo, and may be relevant for their therapeutic use.
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Affiliation(s)
- Christophe J Lalaurie
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gordon Street, London WC1H 0AH, UK
| | - Andrew Splevins
- Evox Therapeutics Ltd, Oxford Science Park, Medwar Center, Oxford, England OX4 4HG, UK; Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY UK
| | - Teresa S Barata
- FairJourney Biologics, 823 Rua do Campo Alegre, Porto, Porto 4150-180, Portugal; Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY UK
| | - Karen A Bunting
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY UK
| | - Daniel R Higazi
- Ipsen Biopharm Ltd., Wrexham Industrial Estate, 9 Ash Road, LL13 9UF, UK
| | - Mire Zloh
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Valentina A Spiteri
- Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, Bernard Katz Building, University College London, Gordon Street, London WC1H 0AH, UK.
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15
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Wood VE, Groves K, Wong LM, Kong L, Bird C, Wadhwa M, Quaglia M, Matejtschuk P, Dalby PA. Protein Engineering and HDX Identify Structural Regions of G-CSF Critical to Its Stability and Aggregation. Mol Pharm 2021; 19:616-629. [PMID: 34965730 DOI: 10.1021/acs.molpharmaceut.1c00754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The protein engineering and formulation of therapeutic proteins for prolonged shelf-life remain a major challenge in the biopharmaceutical industry. Understanding the influence of mutations and formulations on the protein structure and dynamics could lead to more predictive approaches to their improvement. Previous intrinsic fluorescence analysis of the chemically denatured granulocyte colony-stimulating factor (G-CSF) suggested that loop AB could subtly reorganize to form an aggregation-prone intermediate state. Hydrogen deuterium exchange mass spectrometry (HDX-MS) has also revealed that excipient binding increased the thermal unfolding transition midpoint (Tm) by stabilizing loop AB. Here, we have combined protein engineering with biophysical analyses and HDX-MS to reveal that increased exchange in a core region of the G-CSF comprising loop AB (ABI, a small helix, ABII) and loop CD packed onto helix B and the beginning of loop BC leads to a decrease in Tm and higher aggregation rates. Furthermore, some mutations can increase the population of the aggregation-prone conformation within the native ensemble, as measured by the greater local exchange within this core region.
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Affiliation(s)
- Victoria E Wood
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Kate Groves
- National Measurement Laboratory at LGC Ltd, Queens Road, Teddington TW11 0LY, U.K
| | - Lok Man Wong
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Luyan Kong
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
| | - Christopher Bird
- National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, U.K
| | - Meenu Wadhwa
- National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, U.K
| | - Milena Quaglia
- National Measurement Laboratory at LGC Ltd, Queens Road, Teddington TW11 0LY, U.K
| | - Paul Matejtschuk
- National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, U.K
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, U.K
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16
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Morris P, García-Arrazola R, Rios-Solis L, Dalby PA. Biophysical characterization of the inactivation of E. coli transketolase by aqueous co-solvents. Sci Rep 2021; 11:23584. [PMID: 34880340 PMCID: PMC8654844 DOI: 10.1038/s41598-021-03001-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 11/09/2022] Open
Abstract
Transketolase (TK) has been previously engineered, using semi-rational directed evolution and substrate walking, to accept increasingly aliphatic, cyclic, and then aromatic substrates. This has ultimately led to the poor water solubility of new substrates, as a potential bottleneck to further exploitation of this enzyme in biocatalysis. Here we used a range of biophysical studies to characterise the response of both E. coli apo- and holo-TK activity and structure to a range of polar organic co-solvents: acetonitrile (AcCN), n-butanol (nBuOH), ethyl acetate (EtOAc), isopropanol (iPrOH), and tetrahydrofuran (THF). The mechanism of enzyme deactivation was found to be predominantly via solvent-induced local unfolding. Holo-TK is thermodynamically more stable than apo-TK and yet for four of the five co-solvents it retained less activity than apo-TK after exposure to organic solvents, indicating that solvent tolerance was not simply correlated to global conformational stability. The co-solvent concentrations required for complete enzyme inactivation was inversely proportional to co-solvent log(P), while the unfolding rate was directly proportional, indicating that the solvents interact with and partially unfold the enzyme through hydrophobic contacts. Small amounts of aggregate formed in some cases, but this was not sufficient to explain the enzyme inactivation. TK was found to be tolerant to 15% (v/v) iPrOH, 10% (v/v) AcCN, or 6% (v/v) nBuOH over 3 h. This work indicates that future attempts to engineer the enzyme to better tolerate co-solvents should focus on increasing the stability of the protein to local unfolding, particularly in and around the cofactor-binding loops.
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Affiliation(s)
- Phattaraporn Morris
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
- Chemical Metrology and Biometry Department, National Institute of Metrology, 3/4-5 Moo 3, Klong 5, Klong Luang, 12120, Pathumthani, Thailand
| | - Ribia García-Arrazola
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Leonardo Rios-Solis
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL, UK
- Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, King's Buildings, Edinburgh, EH9 3JL, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
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17
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Vaud S, Pearcy N, Hanževački M, Van Hagen AMW, Abdelrazig S, Safo L, Ehsaan M, Jonczyk M, Millat T, Craig S, Spence E, Fothergill J, Bommareddy RR, Colin PY, Twycross J, Dalby PA, Minton NP, Jäger CM, Kim DH, Yu J, Maness PC, Lynch S, Eckert CA, Conradie A, Bryan SJ. Engineering improved ethylene production: Leveraging systems biology and adaptive laboratory evolution. Metab Eng 2021; 67:308-320. [PMID: 34245888 DOI: 10.1016/j.ymben.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/26/2021] [Accepted: 07/02/2021] [Indexed: 10/20/2022]
Abstract
Ethylene is a small hydrocarbon gas widely used in the chemical industry. Annual worldwide production currently exceeds 150 million tons, producing considerable amounts of CO2 contributing to climate change. The need for a sustainable alternative is therefore imperative. Ethylene is natively produced by several different microorganisms, including Pseudomonas syringae pv. phaseolicola via a process catalyzed by the ethylene-forming enzyme (EFE), subsequent heterologous expression of EFE has led to ethylene production in non-native bacterial hosts including Escherichia coli and cyanobacteria. However, solubility of EFE and substrate availability remain rate-limiting steps in biological ethylene production. We employed a combination of genome-scale metabolic modelling, continuous fermentation, and protein evolution to enable the accelerated development of a high efficiency ethylene producing E. coli strain, yielding a 49-fold increase in production, the most significant improvement reported to date. Furthermore, we have clearly demonstrated that this increased yield resulted from metabolic adaptations that were uniquely linked to EFE (wild type versus mutant). Our findings provide a novel solution to deregulate metabolic bottlenecks in key pathways, which can be readily applied to address other engineering challenges.
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Affiliation(s)
- Sophie Vaud
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nicole Pearcy
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Marko Hanževački
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Alexander M W Van Hagen
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Salah Abdelrazig
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Laudina Safo
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Muhammad Ehsaan
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Magdalene Jonczyk
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Thomas Millat
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sean Craig
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Edward Spence
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - James Fothergill
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Rajesh Reddy Bommareddy
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Pierre-Yves Colin
- Department of Biochemical Engineering, Bernard Katz Building, University College London, WC1E 6BT, UK
| | - Jamie Twycross
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK; School of Computer Science, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, Bernard Katz Building, University College London, WC1E 6BT, UK
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, The Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Dong-Hyun Kim
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, NG7 2RD, UK
| | - Jianping Yu
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA
| | - Pin-Ching Maness
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA
| | - Sean Lynch
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, USA; Somalogic, Inc., Boulder, CO, USA
| | - Carrie A Eckert
- Biosciences Center, National Renewable Energy Laboratory (NREL), Golden, CO, USA; Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, USA
| | - Alex Conradie
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Samantha J Bryan
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD, UK.
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18
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Zhang C, Codina N, Tang J, Yu H, Chakroun N, Kozielski F, Dalby PA. Comparison of the pH- and thermally-induced fluctuations of a therapeutic antibody Fab fragment by molecular dynamics simulation. Comput Struct Biotechnol J 2021; 19:2726-2741. [PMID: 34093988 PMCID: PMC8131956 DOI: 10.1016/j.csbj.2021.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/15/2021] [Accepted: 05/01/2021] [Indexed: 11/27/2022] Open
Abstract
Successful development of protein therapeutics depends critically on achieving stability under a range of conditions. A deeper understanding of the drivers of instability across different stress conditions, will enable the engineering of more robust protein scaffolds. We compared the impacts of low pH and high temperature stresses on the structure of a humanized antibody fragment (Fab) A33, using atomistic molecular dynamics simulations, using a recent 2.5 Å crystal structure. This revealed that low-pH induced the loss of native contacts in the domain CL. By contrast, thermal stress led to 5-7% loss of native contacts in all four domains, and simultaneous loss of >30% of native contacts in the VL-VH and CL-CH interfaces. This revealed divergent destabilising pathways under the two different stresses. The underlying cause of instability was probed using FoldX and Rosetta mutation analysis, and packing density calculations. These agreed that mutations in the CL domain, and CL-CH1 interface have the greatest potential for stabilisation of Fab A33. Several key salt bridge losses underpinned the conformational change in CL at low pH, whereas at high temperature, salt bridges became more dynamic, thus contributing to an overall destabilization. Lastly, the unfolding events at the two stress conditions exposed different predicted aggregation-prone regions (APR) to solvent, which would potentially lead to different aggregation mechanisms. Overall, our results identified the early stages of unfolding and stability-limiting regions of Fab A33, and the VH and CL domains as interesting future targets for engineering stability to both pH- and thermal-stresses simultaneously.
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Affiliation(s)
- Cheng Zhang
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1E 7JE, United Kingdom
| | - Nuria Codina
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1E 7JE, United Kingdom
| | - Jiazhi Tang
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
| | - Haoran Yu
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Nesrine Chakroun
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1E 7JE, United Kingdom
| | - Frank Kozielski
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gordon Street, London WC1E 7JE, United Kingdom
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19
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Zhang H, Yang Y, Zhang C, Farid SS, Dalby PA. Machine learning reveals hidden stability code in protein native fluorescence. Comput Struct Biotechnol J 2021; 19:2750-2760. [PMID: 34093990 PMCID: PMC8131987 DOI: 10.1016/j.csbj.2021.04.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 12/15/2022] Open
Abstract
Conformational stability of a protein is usually obtained by spectroscopically measuring the unfolding melting temperature. However, optical spectra under native conditions are considered to contain too little resolution to probe protein stability. Here, we have built and trained a neural network model to take the temperature-dependence of intrinsic fluorescence emission under native-only conditions as inputs, and then predict the spectra at the unfolding transition and denatured state. Application to a therapeutic antibody fragment demonstrates that thermal transitions obtained from the predicted spectra correlate highly with those measured experimentally. Crucially, this work reveals that the temperature-dependence of native fluorescence spectra contains a high-degree of previously hidden information relating native ensemble features to stability. This could lead to rapid screening of therapeutic protein variants and formulations based on spectroscopic measurements under non-denaturing temperatures only.
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Affiliation(s)
- Hongyu Zhang
- Department of Biochemical Engineering, UCL, London WC1E 6BT, UK.,EPSRC Future Targeted Healthcare Manufacturing Hub, UCL, London WC1E 6BT, UK
| | - Yang Yang
- Department of Biochemical Engineering, UCL, London WC1E 6BT, UK.,EPSRC Future Targeted Healthcare Manufacturing Hub, UCL, London WC1E 6BT, UK
| | - Cheng Zhang
- Department of Biochemical Engineering, UCL, London WC1E 6BT, UK
| | - Suzanne S Farid
- Department of Biochemical Engineering, UCL, London WC1E 6BT, UK.,EPSRC Future Targeted Healthcare Manufacturing Hub, UCL, London WC1E 6BT, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, UCL, London WC1E 6BT, UK.,EPSRC Future Targeted Healthcare Manufacturing Hub, UCL, London WC1E 6BT, UK
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20
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Spiteri VA, Doutch J, Rambo RP, Gor J, Dalby PA, Perkins SJ. Solution structure of deglycosylated human IgG1 shows the role of C H2 glycans in its conformation. Biophys J 2021; 120:1814-1834. [PMID: 33675758 DOI: 10.1016/j.bpj.2021.02.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/04/2021] [Accepted: 02/24/2021] [Indexed: 02/06/2023] Open
Abstract
The human immunoglobulin G (IgG) class is the most prevalent antibody in serum, with the IgG1 subclass being the most abundant. IgG1 is composed of two Fab regions connected to a Fc region through a 15-residue hinge peptide. Two glycan chains are conserved in the Fc region in IgG; however, their importance for the structure of intact IgG1 has remained unclear. Here, we subjected glycosylated and deglycosylated monoclonal human IgG1 (designated as A33) to a comparative multidisciplinary structural study of both forms. After deglycosylation using peptide:N-glycosidase F, analytical ultracentrifugation showed that IgG1 remained monomeric and the sedimentation coefficients s020,w of IgG1 decreased from 6.45 S by 0.16-0.27 S. This change was attributed to the reduction in mass after glycan removal. X-ray and neutron scattering revealed changes in the Guinier structural parameters after deglycosylation. Although the radius of gyration (RG) was unchanged, the cross-sectional radius of gyration (RXS-1) increased by 0.1 nm, and the commonly occurring distance peak M2 of the distance distribution curve P(r) increased by 0.4 nm. These changes revealed that the Fab-Fc separation in IgG1 was perturbed after deglycosylation. To explain these changes, atomistic scattering modeling based on Monte Carlo simulations resulted in 123,284 and 119,191 trial structures for glycosylated and deglycosylated IgG1 respectively. From these, 100 x-ray and neutron best-fit models were determined. For these, principal component analyses identified five groups of structural conformations that were different for glycosylated and deglycosylated IgG1. The Fc region in glycosylated IgG1 showed a restricted range of conformations relative to the Fab regions, whereas the Fc region in deglycosylated IgG1 showed a broader conformational spectrum. These more variable Fc conformations account for the loss of binding to the Fcγ receptor in deglycosylated IgG1.
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Affiliation(s)
- Valentina A Spiteri
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - James Doutch
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, United Kingdom
| | - Robert P Rambo
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Jayesh Gor
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, United Kingdom
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.
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21
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Hales JE, Aoudjane S, Aeppli G, Dalby PA. Proof-of-concept analytical instrument for label-free optical deconvolution of protein species in a mixture. J Chromatogr A 2021; 1641:461968. [PMID: 33611116 DOI: 10.1016/j.chroma.2021.461968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/18/2021] [Accepted: 02/01/2021] [Indexed: 11/27/2022]
Abstract
The adoption of process analytical technologies by the biopharmaceutical industry can reduce the cost of therapeutic drugs and facilitate investigation of new bioprocesses. Control of critical process parameters to retain critical product quality attributes within strict bounds is important for ensuring a consistently high product quality, but developing the sophisticated analytical technologies required has proven to be a major challenge. Here, we demonstrate a new optical technique for continuous monitoring of protein species as they are eluted from a chromatographic column, even when they fully co-elute with other protein species, without making any assumption about or peak-fitting to the elution profile. To achieve this, we designed and constructed a time-resolved intrinsic fluorescence lifetime chromatograph, and established an analytical framework for deconvolving and quantifying distinct but co-eluting protein species in real time. This proof-of-concept technology has potentially useful applications as a process analytical technology and more generally as an analytical technique for label-free quantification of proteins in mixtures.
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Affiliation(s)
- John E Hales
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
| | - Samir Aoudjane
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK
| | - Gabriel Aeppli
- London Centre for Nanotechnology, 17-19 Gordon Street, London, WC1H 0AH, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London, WC1E 6BT, UK.
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22
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Chauhan VM, Zhang H, Dalby PA, Aylott JW. Advancements in the co-formulation of biologic therapeutics. J Control Release 2020; 327:397-405. [PMID: 32798639 PMCID: PMC7426274 DOI: 10.1016/j.jconrel.2020.08.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 12/17/2022]
Abstract
Biologic therapeutics are the medicines of the future and are destined to transform the approaches by which the causes and symptoms of diseases are cured and alleviated. These approaches will be accelerated through the development of novel strategies that target multiple pharmacologically active sites using a combination of different biologics, or mixtures of biologics and small molecule therapeutics. However, for this potential to be realised, advancements in co-formulation strategies for biologic therapeutics must be established. This review describes the current and emerging developments within this field and highlights the challenges and potential solutions, that will pave-the-way towards their clinical translation.
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Affiliation(s)
- Veeren M. Chauhan
- Advanced Materials & Healthcare Technologies Group, School of Pharmacy, University of Nottingham, Boots Science Building, Science Road, Nottingham, NG7 2RD, UK,Corresponding author
| | - Hongyu Zhang
- Future Targeted Healthcare Manufacturing Hub, Biochemical Engineering, University College London, Bernard Katz Building, Gordon Street, London, WC1H 0AH, UK
| | - Paul A. Dalby
- Future Targeted Healthcare Manufacturing Hub, Biochemical Engineering, University College London, Bernard Katz Building, Gordon Street, London, WC1H 0AH, UK
| | - Jonathan W. Aylott
- Advanced Materials & Healthcare Technologies Group, School of Pharmacy, University of Nottingham, Boots Science Building, Science Road, Nottingham, NG7 2RD, UK
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23
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Wood VE, Groves K, Cryar A, Quaglia M, Matejtschuk P, Dalby PA. HDX and In Silico Docking Reveal that Excipients Stabilize G-CSF via a Combination of Preferential Exclusion and Specific Hotspot Interactions. Mol Pharm 2020; 17:4637-4651. [PMID: 33112626 DOI: 10.1021/acs.molpharmaceut.0c00877] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Assuring the stability of therapeutic proteins is a major challenge in the biopharmaceutical industry, and a better molecular understanding of the mechanisms through which formulations influence their stability is an ongoing priority. While the preferential exclusion effects of excipients are well known, the additional presence and impact of specific protein-excipient interactions have proven to be more elusive to identify and characterize. We have taken a combined approach of in silico molecular docking and hydrogen deuterium exchange-mass spectrometry (HDX-MS) to characterize the interactions between granulocyte colony-stimulating factor (G-CSF), and some common excipients. These interactions were related to their influence on the thermal-melting temperatures (Tm) for the nonreversible unfolding of G-CSF in liquid formulations. The residue-level interaction sites predicted in silico correlated well with those identified experimentally and highlighted the potential impact of specific excipient interactions on the Tm of G-CSF.
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Affiliation(s)
- Victoria E Wood
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Kate Groves
- National Measurement Laboratory at LGC Ltd., Queens Road, Teddington TW11 0LY, United Kingdom
| | - Adam Cryar
- National Measurement Laboratory at LGC Ltd., Queens Road, Teddington TW11 0LY, United Kingdom
| | - Milena Quaglia
- National Measurement Laboratory at LGC Ltd., Queens Road, Teddington TW11 0LY, United Kingdom
| | - Paul Matejtschuk
- National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
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24
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Wilkinson HC, Dalby PA. Fine-tuning the activity and stability of an evolved enzyme active-site through noncanonical amino-acids. FEBS J 2020; 288:1935-1955. [PMID: 32897608 DOI: 10.1111/febs.15560] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/14/2020] [Accepted: 09/02/2020] [Indexed: 01/17/2023]
Abstract
Site-specific saturation mutagenesis within enzyme active sites can radically alter reaction specificity, though often with a trade-off in stability. Extending saturation mutagenesis with a range of noncanonical amino acids (ncAA) potentially increases the ability to improve activity and stability simultaneously. Previously, an Escherichia coli transketolase variant (S385Y/D469T/R520Q) was evolved to accept aromatic aldehydes not converted by wild-type. The aromatic residue Y385 was critical to the new acceptor substrate binding, and so was explored here beyond the natural aromatic residues, to probe side chain structure and electronics effects on enzyme function and stability. A series of five variants introduced decreasing aromatic ring electron density at position 385 in the order para-aminophenylalanine (pAMF), tyrosine (Y), phenylalanine (F), para-cyanophenylalanine (pCNF) and para-nitrophenylalanine (pNTF), and simultaneously modified the hydrogen-bonding potential of the aromatic substituent from accepting to donating. The fine-tuning of residue 385 yielded variants with a 43-fold increase in specific activity for 50 mm 3-HBA and 100% increased kcat (pCNF), 290% improvement in Km (pNTF), 240% improvement in kcat /Km (pAMF) and decreased substrate inhibition relative to Y. Structural modelling suggested switching of the ring-substituted functional group, from donating to accepting, stabilised a helix-turn (D259-H261) through an intersubunit H-bond with G262, to give a 7.8 °C increase in the thermal transition mid-point, Tm , and improved packing of pAMF. This is one of the first examples in which both catalytic activity and stability are simultaneously improved via site-specific ncAA incorporation into an enzyme active site, and further demonstrates the benefits of expanding designer libraries to include ncAAs.
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Affiliation(s)
- Henry C Wilkinson
- Department of Biochemical Engineering, University College London, London, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, UK
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25
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Yu H, Hernández López RI, Steadman D, Méndez‐Sánchez D, Higson S, Cázares‐Körner A, Sheppard TD, Ward JM, Hailes HC, Dalby PA. Engineering transketolase to accept both unnatural donor and acceptor substrates and produce α‐hydroxyketones. FEBS J 2019; 287:1758-1776. [DOI: 10.1111/febs.15108] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/26/2019] [Accepted: 10/23/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Haoran Yu
- Department of Biochemical Engineering University College London UK
| | | | | | | | - Sally Higson
- Department of Chemistry University College London UK
| | | | | | - John M. Ward
- Department of Biochemical Engineering University College London UK
| | | | - Paul A. Dalby
- Department of Biochemical Engineering University College London UK
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26
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Wilkinson HC, Dalby PA. Novel insights into transketolase activation by cofactor binding identifies two native species subpopulations. Sci Rep 2019; 9:16116. [PMID: 31695144 PMCID: PMC6834573 DOI: 10.1038/s41598-019-52647-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/21/2019] [Indexed: 12/02/2022] Open
Abstract
Transketolase (TK) cofactor binding has been studied extensively over many years, yet certain mysteries remain, such as a lack of consensus on the cooperativity of thiamine pyrophosphate (TPP) binding into the two active sites, in the presence and absence of the divalent cation, Mg2+. Using a novel fluorescence-based assay, we determined directly the dissociation constants and cooperativity of TPP binding and provide the first comprehensive study over a broad range of cofactor concentrations. We confirmed the high-affinity dissociation constants and revealed a dependence of both the affinity and cooperativity of binding on [Mg2+], which explained the previous lack of consensus. A second, discrete and previously uncharacterised low-affinity TPP binding-site was also observed, and hence indicated the existence of two forms of TK with high- (TKhigh) and low-affinity (TKlow). The relative proportions of each dimer were independent of the monomer-dimer transition, as probed by analytical ultracentrifugation at various [TK]. Mass spectrometry revealed that chemical oxidation of TKlow led to the formation of TKhigh, which was 22-fold more active than TKlow. Finally, we propose a two-species model of transketolase activation that describes the interconversions between apo-/holo-TKhigh and TKlow, and the potential to significantly improve biocatalytic activity by populating only the most active form.
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Affiliation(s)
- Henry C Wilkinson
- Department of Biochemical Engineering, University College London, London, WC1E 6BT, UK
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, WC1E 6BT, UK.
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27
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Robinson MJ, Matejtschuk P, Longstaff C, Dalby PA. Selective Stabilization and Destabilization of Protein Domains in Tissue-Type Plasminogen Activator Using Formulation Excipients. Mol Pharm 2019; 16:744-755. [PMID: 30565948 DOI: 10.1021/acs.molpharmaceut.8b01024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Multidomain biotherapeutic proteins present additional behavioral and analytical challenges for the optimization of their kinetic stability by formulation. Tissue-type plasminogen activator (tPA) comprises six protein domains that exhibit a complex and pH-dependent thermal unfolding profile, due to partially independent domain unfolding. Here we have used tPA as a model for evaluating the relationships between various thermal unfolding and aggregation parameters in multidomain proteins. We show that changes in the thermal unfolding profile of tPA were parametrized by the overall thermal midpoint transition temperature, Tm, and the Van't Hoff entropy for unfolding, Δ Svh, which is a measure of unfolding cooperativity. The kinetics of degradation at 45 °C, leading to aggregation, were measured as rates of monomer and activity loss. These two rates were found to be coincident at all pH. Aggregation accelerated at pH 4 due to the early unfolding of the serine protease N-terminal domain (SP-N), whereas at pH 5-8, the fraction unfolded at 45 °C ( f45) was <1%, resulting in a baseline rate of aggregation from the native ensemble. We used a Design of Experiments (DoE) approach to evaluate how formulation excipients impact and control the thermal unfolding profile for tPA and found that the relative stability of each of the tPA domains was dependent on the formulation. Therefore, the optimization of formulations for complex multidomain proteins such as tPA may need to be multiobjective, with careful selection of the desired attributes that improve stability. As aggregation rates (ln v) correlated well to Tm ( R2 = 0.77) and Δ Svh ( R2 = 0.71) but not Tagg ( R2 = 0.01), we analyzed how formulation excipients and pH would be able to optimize Tm and Δ Svh. Formulation excipient behaviors were found to group according to their combined impact on Tm and Δ Svh. The effects of each excipient were often selectively stabilizing or destabilizing to specific tPA domains and changed the stability of particular domains relative to the others. The types of mechanism by which this could occur might involve specific interactions with the protein surface, or otherwise effects that are mediated via the solvent as a result of the different surface hydrophobicities and polarities of each domain.
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Affiliation(s)
- Mathew J Robinson
- Department of Biochemical Engineering , University College London , Gower Street , London WC1E 6BT , U.K
| | - Paul Matejtschuk
- National Institute for Biological Standards and Control , South Mimms, Potters Bar , Hertfordshire EN6 3QG , U.K
| | - Colin Longstaff
- National Institute for Biological Standards and Control , South Mimms, Potters Bar , Hertfordshire EN6 3QG , U.K
| | - Paul A Dalby
- Department of Biochemical Engineering , University College London , Gower Street , London WC1E 6BT , U.K
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28
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Zhang C, Samad M, Yu H, Chakroun N, Hilton D, Dalby PA. Computational Design To Reduce Conformational Flexibility and Aggregation Rates of an Antibody Fab Fragment. Mol Pharm 2018; 15:3079-3092. [PMID: 29897777 DOI: 10.1021/acs.molpharmaceut.8b00186] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Computationally guided semirational design has significant potential for improving the aggregation kinetics of protein biopharmaceuticals. While improvement in the global conformational stability can stabilize proteins to aggregation under some conditions, previous studies suggest that such an approach is limited, because thermal transition temperatures ( Tm) and the fraction of protein unfolded ( fT) tend to only correlate with aggregation kinetics where the protein is incubated at temperatures approaching the Tm. This is because under these conditions, aggregation from globally unfolded protein becomes dominant. However, under native conditions, the aggregation kinetics are presumed to be dependent on local structural fluctuations or partial unfolding of the native state, which reveal regions of high propensity to form protein-protein interactions that lead to aggregation. In this work, we have targeted the design of stabilizing mutations to regions of the A33 Fab surface structure, which were predicted to be more flexible. This Fab already has high global stability, and global unfolding is not the main cause of aggregation under most conditions. Therefore, the aim was to reduce the conformational flexibility and entropy of the native protein at various locations and thus identify which of those regions has the greatest influence on the aggregation kinetics. Highly dynamic regions of structure were identified through both molecular dynamics simulation and B-factor analysis of related X-ray crystal structures. The most flexible residues were mutated into more stable variants, as predicted by Rosetta, which evaluates the ΔΔ GND for each potential point mutation. Additional destabilizing variants were prepared as controls to evaluate the prediction accuracy and also to assess the general influence of conformational stability on aggregation kinetics. The thermal conformational stability, and aggregation rates of 18 variants at 65 °C, were each examined at pH 4, 200 mM ionic strength, under which conditions the initial wild-type protein was <5% unfolded. Variants with decreased Tm values led to more rapid aggregation due to an increase in the fraction of protein unfolded under the conditions studied. As expected, no significant improvements were observed in the global conformational stability as measured by Tm. However, 6 of the 12 stable variants led to an increase in the cooperativity of unfolding, consistent with lower conformational flexibility and entropy in the native ensemble. Three of these had 5-11% lower aggregation rates, and their structural clustering indicated that the local dynamics of the C-terminus of the heavy chain had a role in influencing the aggregation rate.
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Affiliation(s)
- Cheng Zhang
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
| | - Maariyah Samad
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
| | - Haoran Yu
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
| | - Nesrine Chakroun
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
| | - David Hilton
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
| | - Paul A Dalby
- Department of Biochemical Engineering , University College London , Gordon Street , London WC1E 7JE , U.K
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29
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Robinson MJ, Matejtschuk P, Bristow AF, Dalby PA. Tm-Values and Unfolded Fraction Can Predict Aggregation Rates for Granulocyte Colony Stimulating Factor Variant Formulations but Not under Predominantly Native Conditions. Mol Pharm 2017; 15:256-267. [DOI: 10.1021/acs.molpharmaceut.7b00876] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mathew J. Robinson
- Department
of Biochemical Engineering, University College London, London WC1E 7JE, U.K
| | - Paul Matejtschuk
- National Institute
of Biological Standards and Control (NIBSC), South Mimms, Potters Bar, Hertfordshire EN6 3QG, U.K
| | - Adrian F. Bristow
- National Institute
of Biological Standards and Control (NIBSC), South Mimms, Potters Bar, Hertfordshire EN6 3QG, U.K
| | - Paul A. Dalby
- Department
of Biochemical Engineering, University College London, London WC1E 7JE, U.K
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30
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Yu H, Yan Y, Zhang C, Dalby PA. Two strategies to engineer flexible loops for improved enzyme thermostability. Sci Rep 2017; 7:41212. [PMID: 28145457 PMCID: PMC5286519 DOI: 10.1038/srep41212] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 12/16/2016] [Indexed: 11/19/2022] Open
Abstract
Flexible sites are potential targets for engineering the stability of enzymes. Nevertheless, the success rate of the rigidifying flexible sites (RFS) strategy is still low due to a limited understanding of how to determine the best mutation candidates. In this study, two parallel strategies were applied to identify mutation candidates within the flexible loops of Escherichia coli transketolase (TK). The first was a “back to consensus mutations” approach, and the second was computational design based on ΔΔG calculations in Rosetta. Forty-nine single variants were generated and characterised experimentally. From these, three single-variants I189H, A282P, D143K were found to be more thermostable than wild-type TK. The combination of A282P with H192P, a variant constructed previously, resulted in the best all-round variant with a 3-fold improved half-life at 60 °C, 5-fold increased specific activity at 65 °C, 1.3-fold improved kcat and a Tm increased by 5 °C above that of wild type. Based on a statistical analysis of the stability changes for all variants, the qualitative prediction accuracy of the Rosetta program reached 65.3%. Both of the two strategies investigated were useful in guiding mutation candidates to flexible loops, and had the potential to be used for other enzymes.
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Affiliation(s)
- Haoran Yu
- Department of Biochemical Engineering, University College London, Gordon Street, London, WC1H 0AH, United Kingdom
| | - Yihan Yan
- Department of Biochemical Engineering, University College London, Gordon Street, London, WC1H 0AH, United Kingdom
| | - Cheng Zhang
- Department of Biochemical Engineering, University College London, Gordon Street, London, WC1H 0AH, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, Gordon Street, London, WC1H 0AH, United Kingdom
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31
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Cárdenas-Fernández M, Bawn M, Hamley-Bennett C, Bharat PKV, Subrizi F, Suhaili N, Ward DP, Bourdin S, Dalby PA, Hailes HC, Hewitson P, Ignatova S, Kontoravdi C, Leak DJ, Shah N, Sheppard TD, Ward JM, Lye GJ. An integrated biorefinery concept for conversion of sugar beet pulp into value-added chemicals and pharmaceutical intermediates. Faraday Discuss 2017; 202:415-431. [DOI: 10.1039/c7fd00094d] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including d-glucose (Glu), l-arabinose (Ara) and d-galacturonic acid (GalAc). This work describes the technical feasibility of an integrated biorefinery concept for the fractionation of SBP and conversion of these monosaccharides into value-added products. SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release Glu that can then be fermented by a commercial yeast strain to produce bioethanol at a high yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC) or ultrafiltration into streams suitable for subsequent enzymatic upgrading. Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the conversion of Ara and GalAc into higher value products was explored. In particular the conversion of Ara into l-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be selectively aminated to the corresponding chiral aminopolyol. The current work is addressing the upgrading of the remaining SBP monomer, GalAc, and the modelling of the biorefinery concept to enable economic and Life Cycle Analysis (LCA).
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32
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Affaticati PE, Dai SB, Payongsri P, Hailes HC, Tittmann K, Dalby PA. Structural Analysis of an Evolved Transketolase Reveals Divergent Binding Modes. Sci Rep 2016; 6:35716. [PMID: 27767080 PMCID: PMC5073344 DOI: 10.1038/srep35716] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/22/2016] [Indexed: 11/09/2022] Open
Abstract
The S385Y/D469T/R520Q variant of E. coli transketolase was evolved previously with three successive smart libraries, each guided by different structural, bioinformatical or computational methods. Substrate-walking progressively shifted the target acceptor substrate from phosphorylated aldehydes, towards a non-phosphorylated polar aldehyde, a non-polar aliphatic aldehyde, and finally a non-polar aromatic aldehyde. Kinetic evaluations on three benzaldehyde derivatives, suggested that their active-site binding was differentially sensitive to the S385Y mutation. Docking into mutants generated in silico from the wild-type crystal structure was not wholly satisfactory, as errors accumulated with successive mutations, and hampered further smart-library designs. Here we report the crystal structure of the S385Y/D469T/R520Q variant, and molecular docking of three substrates. This now supports our original hypothesis that directed-evolution had generated an evolutionary intermediate with divergent binding modes for the three aromatic aldehydes tested. The new active site contained two binding pockets supporting π-π stacking interactions, sterically separated by the D469T mutation. While 3-formylbenzoic acid (3-FBA) preferred one pocket, and 4-FBA the other, the less well-accepted substrate 3-hydroxybenzaldehyde (3-HBA) was caught in limbo with equal preference for the two pockets. This work highlights the value of obtaining crystal structures of evolved enzyme variants, for continued and reliable use of smart library strategies.
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Affiliation(s)
- Pierre E Affaticati
- Department of Biochemical Engineering, Gordon Street, University College London, WC1H 0AH, UK
| | - Shao-Bo Dai
- Albrecht-von-Haller Institute, Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, 37077 Göttingen, Germany
| | - Panwajee Payongsri
- Department of Biochemical Engineering, Gordon Street, University College London, WC1H 0AH, UK
| | - Helen C Hailes
- Department of Chemistry, 20 Gordon Street, University College London, WC1H 0AJ, UK
| | - Kai Tittmann
- Albrecht-von-Haller Institute, Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, 37077 Göttingen, Germany
| | - Paul A Dalby
- Department of Biochemical Engineering, Gordon Street, University College London, WC1H 0AH, UK
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33
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Barata TS, Zhang C, Dalby PA, Brocchini S, Zloh M. Identification of Protein-Excipient Interaction Hotspots Using Computational Approaches. Int J Mol Sci 2016; 17:ijms17060853. [PMID: 27258262 PMCID: PMC4926387 DOI: 10.3390/ijms17060853] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/12/2016] [Accepted: 05/24/2016] [Indexed: 01/30/2023] Open
Abstract
Protein formulation development relies on the selection of excipients that inhibit protein–protein interactions preventing aggregation. Empirical strategies involve screening many excipient and buffer combinations using force degradation studies. Such methods do not readily provide information on intermolecular interactions responsible for the protective effects of excipients. This study describes a molecular docking approach to screen and rank interactions allowing for the identification of protein–excipient hotspots to aid in the selection of excipients to be experimentally screened. Previously published work with Drosophila Su(dx) was used to develop and validate the computational methodology, which was then used to determine the formulation hotspots for Fab A33. Commonly used excipients were examined and compared to the regions in Fab A33 prone to protein–protein interactions that could lead to aggregation. This approach could provide information on a molecular level about the protective interactions of excipients in protein formulations to aid the more rational development of future formulations.
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Affiliation(s)
- Teresa S Barata
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, University College London, Biochemical Engineering Department, Bernard Katz Building, Gordon Street, London WC1H 0AH, UK.
- UCL School of Pharmacy, Department of Pharmaceutics, 29-39 Brunswick Square, London WC1N 1AX, UK.
| | - Cheng Zhang
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, University College London, Biochemical Engineering Department, Bernard Katz Building, Gordon Street, London WC1H 0AH, UK.
| | - Paul A Dalby
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, University College London, Biochemical Engineering Department, Bernard Katz Building, Gordon Street, London WC1H 0AH, UK.
| | - Steve Brocchini
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, University College London, Biochemical Engineering Department, Bernard Katz Building, Gordon Street, London WC1H 0AH, UK.
- UCL School of Pharmacy, Department of Pharmaceutics, 29-39 Brunswick Square, London WC1N 1AX, UK.
| | - Mire Zloh
- Department of Pharmacy, Pharmacology and Postgraduate Medicine, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK.
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34
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Abstract
The analytical characterization of biopharmaceuticals is a fundamental step in the early stages of development and prediction of their behavior in bioprocesses. Protein aggregation in particular is a common issue as it affects all stages of product development. In the present work, we investigate the stability and the aggregation kinetics of A33Fab, a therapeutically relevant humanized antibody fragment at a wide range of pH, ionic strength, and temperature. We show that the propensity of A33Fab to aggregate under thermally accelerated conditions is pH and ionic-strength dependent with a stronger destabilizing effect of ionic strength at low pH. In the absence of added salts, A33Fab molecules appear to be protected from aggregation due to electrostatic colloidal repulsion at low pH. Analysis by transmission electron microscopy identified significantly different aggregate species formed at low and high pH. The correlations between apparent midpoints of thermal transitions (Tm,app values), or unfolded mole fractions, and aggregation rates are reported here to be significant only at the elevated incubation temperature of 65 °C, where aggregation from the unfolded state predominates. At all other conditions, particularly at 4-45 °C, aggregation of A33 Fab was predominantly from a native-like state, and the kinetics obeyed Arrhenius behavior. Despite this, the rank order of aggregation rates observed at 45 °C, 23 and 4 °C still did not correlate well to each other, indicating that forced degradation at elevated temperatures was not a good screen for predicting behavior at low temperature.
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Affiliation(s)
- Nesrine Chakroun
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K.,Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K
| | - David Hilton
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K.,Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K
| | - Shahina S Ahmad
- Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K
| | - Geoffrey W Platt
- Unchained Laboratories, Unit 706, Avenue E West, Thorp Arch Estate, Wetherby LS23 7EG, U.K
| | - Paul A Dalby
- EPSRC Centre for Innovative Manufacturing in Emergent Macromolecular Therapies, Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K.,Department of Biochemical Engineering, University College London , London WC1H 0AH, U.K
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35
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Deszcz D, Affaticati P, Ladkau N, Gegel A, Ward JM, Hailes HC, Dalby PA. Single active-site mutants are sufficient to enhance serine:pyruvate α-transaminase activity in an ω-transaminase. FEBS J 2015; 282:2512-26. [PMID: 25846556 DOI: 10.1111/febs.13293] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 02/19/2015] [Accepted: 04/01/2015] [Indexed: 11/28/2022]
Abstract
We have analyzed the natural evolution of transaminase structure and sequence between an α-transaminase serine-pyruvate aminotransferase and an ω-transaminase from Chromobacterium violaceum with < 20% sequence identity, and identified the active-site regions that are least conserved structurally. We also show that these structural changes correlate strongly with transaminase substrate specificity during evolution and therefore might normally be presumed to be essential determinants of substrate specificity. However, key residues are often conserved spatially during evolution and yet originate from within a different region of the sequence via structural reorganizations. In the present study, we also show that α-transaminase-type serine-pyruvate aminotransferase activity can be engineered into the CV2025 ω-transaminase scaffold with any one of many possible single-point mutations at three key positions, without the requirement for significant backbone remodeling, or repositioning of the residue from a different region of sequence. This finding has significant implications for enzyme redesign in which solutions to substrate specificity changes may be found more efficiently than is achieved by engineering in all sequence and structure determinants identified by correlation to substrate specificity.
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Affiliation(s)
- Dawid Deszcz
- Department of Biochemical Engineering, University College London, UK
| | - Pierre Affaticati
- Department of Biochemical Engineering, University College London, UK
| | - Nadine Ladkau
- Department of Chemistry, University College London, UK
| | - Alex Gegel
- Department of Biochemical Engineering, University College London, UK
| | - John M Ward
- Department of Biochemical Engineering, University College London, UK
| | | | - Paul A Dalby
- Department of Biochemical Engineering, University College London, UK
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36
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Payongsri P, Steadman D, Hailes HC, Dalby PA. Second generation engineering of transketolase for polar aromatic aldehyde substrates. Enzyme Microb Technol 2015; 71:45-52. [DOI: 10.1016/j.enzmictec.2015.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/20/2015] [Accepted: 01/22/2015] [Indexed: 10/24/2022]
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37
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Rayner LE, Hui GK, Gor J, Heenan RK, Dalby PA, Perkins SJ. The solution structures of two human IgG1 antibodies show conformational stability and accommodate their C1q and FcγR ligands. J Biol Chem 2015; 290:8420-38. [PMID: 25659433 PMCID: PMC4375494 DOI: 10.1074/jbc.m114.631002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/28/2015] [Indexed: 11/06/2022] Open
Abstract
The human IgG1 antibody subclass shows distinct properties compared with the IgG2, IgG3, and IgG4 subclasses and is the most exploited subclass in therapeutic antibodies. It is the most abundant subclass, has a half-life as long as that of IgG2 and IgG4, binds the FcγR receptor, and activates complement. There is limited structural information on full-length human IgG1 because of the challenges of crystallization. To rectify this, we have studied the solution structures of two human IgG1 6a and 19a monoclonal antibodies in different buffers at different temperatures. Analytical ultracentrifugation showed that both antibodies were predominantly monomeric, with sedimentation coefficients s20,w (0) of 6.3-6.4 S. Only a minor dimer peak was observed, and the amount was not dependent on buffer conditions. Solution scattering showed that the x-ray radius of gyration Rg increased with salt concentration, whereas the neutron Rg values remained unchanged with temperature. The x-ray and neutron distance distribution curves P(r) revealed two peaks, M1 and M2, whose positions were unchanged in different buffers to indicate conformational stability. Constrained atomistic scattering modeling revealed predominantly asymmetric solution structures for both antibodies with extended hinge structures. Both structures were similar to the only known crystal structure of full-length human IgG1. The Fab conformations in both structures were suitably positioned to permit the Fc region to bind readily to its FcγR and C1q ligands without steric clashes, unlike human IgG4. Our molecular models for human IgG1 explain its immune activities, and we discuss its stability and function for therapeutic applications.
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Affiliation(s)
- Lucy E Rayner
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Gar Kay Hui
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Richard K Heenan
- the ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom, and
| | - Paul A Dalby
- the Department of Biochemical Engineering, Division of Engineering, Roberts Building, University College London, Gower Street, London WC1E 7JE, United Kingdom
| | - Stephen J Perkins
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom,
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38
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Rayner LE, Hui GK, Gor J, Heenan RK, Dalby PA, Perkins SJ. The Fab conformations in the solution structure of human immunoglobulin G4 (IgG4) restrict access to its Fc region: implications for functional activity. J Biol Chem 2014; 289:20740-56. [PMID: 24876381 PMCID: PMC4110284 DOI: 10.1074/jbc.m114.572404] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 05/12/2014] [Indexed: 12/24/2022] Open
Abstract
Human IgG4 antibody shows therapeutically useful properties compared with the IgG1, IgG2, and IgG3 subclasses. Thus IgG4 does not activate complement and shows conformational variability. These properties are attributable to its hinge region, which is the shortest of the four IgG subclasses. Using high throughput scattering methods, we studied the solution structure of wild-type IgG4(Ser(222)) and a hinge mutant IgG4(Pro(222)) in different buffers and temperatures where the proline substitution suppresses the formation of half-antibody. Analytical ultracentrifugation showed that both IgG4 forms were principally monomeric with sedimentation coefficients s20,w(0) of 6.6-6.8 S. A monomer-dimer equilibrium was observed in heavy water buffer at low temperature. Scattering showed that the x-ray radius of gyration Rg was unchanged with concentration in 50-250 mm NaCl buffers, whereas the neutron Rg values showed a concentration-dependent increase as the temperature decreased in heavy water buffers. The distance distribution curves (P(r)) revealed two peaks, M1 and M2, that shifted below 2 mg/ml to indicate concentration-dependent IgG4 structures in addition to IgG4 dimer formation at high concentration in heavy water. Constrained x-ray and neutron scattering modeling revealed asymmetric solution structures for IgG4(Ser(222)) with extended hinge structures. The IgG4(Pro(222)) structure was similar. Both IgG4 structures showed that their Fab regions were positioned close enough to the Fc region to restrict C1q binding. Our new molecular models for IgG4 explain its inability to activate complement and clarify aspects of its stability and function for therapeutic applications.
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Affiliation(s)
- Lucy E Rayner
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building and
| | - Gar Kay Hui
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building and
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building and
| | - Richard K Heenan
- ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, Division of Engineering, Roberts Building, University College London, Gower Street, London WC1E 6BT, United Kingdom and
| | - Stephen J Perkins
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building and
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Sagar DM, Aoudjane S, Gaudet M, Aeppli G, Dalby PA. Optically induced thermal gradients for protein characterization in nanolitre-scale samples in microfluidic devices. Sci Rep 2013; 3:2130. [PMID: 23823279 PMCID: PMC3703920 DOI: 10.1038/srep02130] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/30/2013] [Indexed: 11/16/2022] Open
Abstract
Proteins are the most vital biological functional units in every living cell. Measurement
of protein stability is central to understanding their structure, function and role in
diseases. While proteins are also sought as therapeutic agents, they can cause diseases by
misfolding and aggregation in vivo. Here we demonstrate a novel method to measure protein
stability and denaturation kinetics, on unprecedented timescales, through optically-induced
heating of nanolitre samples in microfluidic capillaries. We obtain protein denaturation
kinetics as a function of temperature, and accurate thermodynamic stability data, from a
snapshot experiment on a single sample. We also report the first experimental
characterization of optical heating in controlled microcapillary flow, verified by
computational fluid dynamics modelling. Our results demonstrate that we now have the
engineering science in hand to design integrated all-optical microfluidic chips for a
diverse range of applications including in-vitro DNA amplification, healthcare diagnostics,
and flow chemistry.
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Affiliation(s)
- D M Sagar
- Department of Biochemical Engineering, Torrington Place, University College London, London, WC1E 7JE, UK
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40
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Rayner LE, Kadkhodayi-Kholghi N, Heenan RK, Gor J, Dalby PA, Perkins SJ. The solution structure of rabbit IgG accounts for its interactions with the Fc receptor and complement C1q and its conformational stability. J Mol Biol 2012. [PMID: 23178865 DOI: 10.1016/j.jmb.2012.11.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Solution structures for antibodies are critical to understand function and therapeutic applications. The stability of the solution structure of rabbit IgG in different buffers and temperatures was determined by analytical ultracentrifugation and X-ray and neutron scattering. Rabbit IgG showed a principally monomeric species, which is well resolved from small amounts of a dimeric species. The proportion of dimer increased with increased concentration, decreased temperature and heavy water from 8% to 25% in all buffers except for high salt (250 mM NaCl). The Guinier X-ray radius of gyration R(G) likewise increased with concentration in 137 mM NaCl buffer but was unchanged in 250 mM NaCl buffer. The Guinier neutron R(G) values increased as the temperature decreased. The X-ray and neutron distance distribution curves P(r) revealed two peaks, M1 and M2, whose positions did not change with concentration to indicate unchanged structures under all these conditions. The maximum dimension increased with concentration because of dimer formation. Constrained scattering modeling reproducibly revealed very similar asymmetric solution structures for monomeric rabbit IgG in different buffers, in which the Fab-Fc and Fab-Fab pairs were separated by maximally extended hinge structures. The dimer was best modeled by two pairs of Fab regions forming tip-to-tip contacts. The intact rabbit IgG structures explained the ability of its two ligands, the Fc receptor and complement C1q, to bind to the top of its Fc region that is fully accessible and unhindered by the Fab regions.
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Affiliation(s)
- Lucy E Rayner
- Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
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43
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Ordidge GC, Mannall G, Liddell J, Dalby PA, Micheletti M. A generic hierarchical screening method for the analysis of microscale refolds using an automated robotic platform. Biotechnol Prog 2012; 28:435-44. [DOI: 10.1002/btpr.1502] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/21/2011] [Indexed: 11/07/2022]
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44
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Payongsri P, Steadman D, Strafford J, MacMurray A, Hailes HC, Dalby PA. Rational substrate and enzyme engineering of transketolase for aromatics. Org Biomol Chem 2012; 10:9021-9. [DOI: 10.1039/c2ob25751c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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45
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Grant Y, Matejtschuk P, Bird C, Wadhwa M, Dalby PA. Freeze drying formulation using microscale and design of experiment approaches: a case study using granulocyte colony-stimulating factor. Biotechnol Lett 2011; 34:641-8. [DOI: 10.1007/s10529-011-0822-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
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46
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Strafford J, Payongsri P, Hibbert EG, Morris P, Batth SS, Steadman D, Smith MEB, Ward JM, Hailes HC, Dalby PA. Directed evolution to re-adapt a co-evolved network within an enzyme. J Biotechnol 2011; 157:237-45. [PMID: 22154561 PMCID: PMC3657141 DOI: 10.1016/j.jbiotec.2011.11.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/19/2011] [Accepted: 11/22/2011] [Indexed: 12/04/2022]
Abstract
We have previously used targeted active-site saturation mutagenesis to identify a number of transketolase single mutants that improved activity towards either glycolaldehyde (GA), or the non-natural substrate propionaldehyde (PA). Here, all attempts to recombine the singles into double mutants led to unexpected losses of specific activity towards both substrates. A typical trade-off occurred between soluble expression levels and specific activity for all single mutants, but many double mutants decreased both properties more severely suggesting a critical loss of protein stability or native folding. Statistical coupling analysis (SCA) of a large multiple sequence alignment revealed a network of nine co-evolved residues that affected all but one double mutant. Such networks maintain important functional properties such as activity, specificity, folding, stability, and solubility and may be rapidly disrupted by introducing one or more non-naturally occurring mutations. To identify variants of this network that would accept and improve upon our best D469 mutants for activity towards PA, we created a library of random single, double and triple mutants across seven of the co-evolved residues, combining our D469 variants with only naturally occurring mutations at the remaining sites. A triple mutant cluster at D469, E498 and R520 was found to behave synergistically for the specific activity towards PA. Protein expression was severely reduced by E498D and improved by R520Q, yet variants containing both mutations led to improved specific activity and enzyme expression, but with loss of solubility and the formation of inclusion bodies. D469S and R520Q combined synergistically to improve kcat 20-fold for PA, more than for any previous transketolase mutant. R520Q also doubled the specific activity of the previously identified D469T to create our most active transketolase mutant to date. Our results show that recombining active-site mutants obtained by saturation mutagenesis can rapidly destabilise critical networks of co-evolved residues, whereas beneficial single mutants can be retained and improved upon by randomly recombining them with natural variants at other positions in the network.
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Affiliation(s)
- John Strafford
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
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47
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Polykarpou EM, Dalby PA, Papageorgiou LG. Optimal synthesis of chromatographic trains for downstream protein processing. Biotechnol Prog 2011; 27:1653-60. [PMID: 21976368 DOI: 10.1002/btpr.670] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/01/2011] [Indexed: 11/08/2022]
Abstract
Downstream bioprocessing and especially chromatographic steps, commonly used for the purification of multicomponent systems, are significant cost drivers in the production of therapeutic proteins. There has been an increased interest in the development of systematic methods for the design of such processes, and the appropriate selection of a series of chromatographic steps is still a major challenge to be addressed. Several models have been developed previously but have assumed that 100% recovery of the desired product is obtained at each chromatographic step. In this work, a mathematical framework is proposed, based on mixed integer optimisation techniques, that removes this assumption and allows full flexibility on the position of retention time cut-points, between which the desired product fraction is collected. The proposed model is demonstrated on three example protein mixtures, each containing up to 13 contaminants and selecting from a set of up to 21 candidate steps. The proposed model results in a reduction of one to three chromatographic steps over solutions that no losses are allowed.
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Jahromi RRF, Morris P, Martinez-Torres RJ, Dalby PA. Structural stability of E. coli transketolase to temperature and pH denaturation. J Biotechnol 2011; 155:209-16. [PMID: 21723889 DOI: 10.1016/j.jbiotec.2011.06.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 06/07/2011] [Accepted: 06/17/2011] [Indexed: 11/15/2022]
Abstract
We have previously shown that the denaturation of TK with urea follows a non-aggregating though irreversible denaturation pathway in which the cofactor binding appears to become altered but without dissociating, then followed at higher urea by partial denaturation of the homodimer prior to any further unfolding or dissociation of the two monomers. Urea is not typically present during biocatalysis, whereas access to TK enzymes that retain activity at increased temperature and extreme pH would be useful for operation under conditions that increase substrate and product stability or solubility. To provide further insight into the underlying causes of its deactivation in process conditions, we have characterised the effects of temperature and pH on the structure, stability, aggregation and activity of Escherichia coli transketolase. The activity of TK was initially found to progressively improve after pre-incubation at increasing temperatures. Loss of activity at higher temperature and low pH resulted primarily from protein denaturation and subsequent irreversible aggregation. By contrast, high pH resulted in the formation of a native-like state that was only partially inactive. The apo-TK enzyme structure content also increased at pH 9 to converge on that of the holo-TK. While cofactor dissociation was previously proposed for high pH deactivation, the observed structural changes in apo-TK but not holo-TK indicate a more complex mechanism.
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Affiliation(s)
- Raha R F Jahromi
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London, UK
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49
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Mahendrarajah K, Dalby PA, Wilkinson B, Jackson SE, Main ER. A high-throughput fluorescence chemical denaturation assay as a general screen for protein–ligand binding. Anal Biochem 2011; 411:155-7. [DOI: 10.1016/j.ab.2010.12.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 12/02/2010] [Accepted: 12/03/2010] [Indexed: 11/26/2022]
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50
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Gaudet M, Remtulla N, Jackson SE, Main ERG, Bracewell DG, Aeppli G, Dalby PA. Protein denaturation and protein:drugs interactions from intrinsic protein fluorescence measurements at the nanolitre scale. Protein Sci 2010; 19:1544-54. [PMID: 20552687 DOI: 10.1002/pro.433] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Protein stability and ligand-binding affinity measurements are widely required for the formulation of biopharmaceutical proteins, protein engineering and drug screening within life science research. Current techniques either consume too much of often precious biological or compound materials, in large sample volumes, or alternatively require chemical labeling with fluorescent tags to achieve measurements at submicrolitre volumes with less sample. Here we present a quantitative and accurate method for the determination of protein stability and the affinity for small molecules, at only 1.5-20 nL optical sample volumes without the need for fluorescent labeling, and that takes advantage of the intrinsic tryptophan fluorescence of most proteins. Coupled to appropriate microfluidic sample preparation methods, the sample requirements could thus be reduced 85,000-fold to just 10(8) molecules. The stability of wild-type FKBP-12 and a destabilizing binding-pocket mutant are studied in the presence and absence of rapamycin, to demonstrate the potential of the technique to both drug screening and protein engineering. The results show that 75% of the interaction energy between FKBP-12 and rapamycin originates from residue Phe99 in the binding site.
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Affiliation(s)
- Matthieu Gaudet
- Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
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