1
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Mirlohi MS, Pishbin E, Dezhkam R, Kiani MJ, Shamloo A, Salami S. Innovative PNA-LB mediated allele-specific LAMP for KRAS mutation profiling on a compact lab-on-a-disc device. Talanta 2024; 276:126224. [PMID: 38772176 DOI: 10.1016/j.talanta.2024.126224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/24/2024] [Accepted: 05/05/2024] [Indexed: 05/23/2024]
Abstract
Tailored healthcare, an approach focused on individual patients, requires integrating emerging interdisciplinary technologies to develop accurate and user-friendly diagnostic tools. KRAS mutations, prevalent in various common cancers, are crucial determinants in selecting patients for novel KRAS inhibitor therapies. This study presents a novel state-of-the-art Lab-on-a-Disc system utilizing peptide nucleic acids-loop backward (PNA-LB) mediated allele-specific loop-mediated isothermal amplification (LAMP) for detecting the frequent G12D KRAS mutation, signifying its superiority over alternative mutation detection approaches. The designed Lab-on-a-Disc system demonstrated exceptional preclinical and technical precision, accuracy, and versatility. By applying varying cutoff values to PNA- LB LAMP reactions, the assay's sensitivity and specificity were increased by 80 % and 90 %, respectively. The device's key advantages include a robust microfluidic Lab-on-a-Disc design, precise rotary control, and a cutting-edge induction heating module. These features enable multiplexing of LAMP reactions with high reproducibility and repeatability, with CV% values less than 3.5 % and 5.5 %, respectively. The device offers several methods for accurate endpoint result detection, including naked-eye observation, RGB image analysis using Python code, and time of fluorescence (Tf) values. Preclinical specificity and sensitivity, assessed using different cutoffs for Eva-Green fluorescence Tf values and pH-sensitive dyes, demonstrated comparable performance to the best standard methods. Overall, this study represents a significant step towards tailoring treatment strategies for cancer patients through precise and efficient mutation detection technologies.
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Affiliation(s)
- Maryam Sadat Mirlohi
- Clinical Biochemistry Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Esmail Pishbin
- Bio-microfluidics Laboratory, Department of Electrical Engineering and Information Technology, Iranian Research Organization for Science and Technology, Tehran, Iran.
| | - Rasool Dezhkam
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran; Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Mohammad Javad Kiani
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Amir Shamloo
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Siamak Salami
- Clinical Biochemistry Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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2
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Tripp A, Braun M, Wieser F, Oberdorfer G, Lechner H. Click, Compute, Create: A Review of Web-based Tools for Enzyme Engineering. Chembiochem 2024:e202400092. [PMID: 38634409 DOI: 10.1002/cbic.202400092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/14/2024] [Accepted: 04/15/2024] [Indexed: 04/19/2024]
Abstract
Enzyme engineering, though pivotal across various biotechnological domains, is often plagued by its time-consuming and labor-intensive nature. This review aims to offer an overview of supportive in silico methodologies for this demanding endeavor. Starting from methods to predict protein structures, to classification of their activity and even the discovery of new enzymes we continue with describing tools used to increase thermostability and production yields of selected targets. Subsequently, we discuss computational methods to modulate both, the activity as well as selectivity of enzymes. Last, we present recent approaches based on cutting-edge machine learning methods to redesign enzymes. With exception of the last chapter, there is a strong focus on methods easily accessible via web-interfaces or simple Python-scripts, therefore readily useable for a diverse and broad community.
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Affiliation(s)
- Adrian Tripp
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010, Graz, Austria
| | - Markus Braun
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010, Graz, Austria
| | - Florian Wieser
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010, Graz, Austria
| | - Gustav Oberdorfer
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010, Graz, Austria
- BioTechMed, Graz, Austria
| | - Horst Lechner
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010, Graz, Austria
- BioTechMed, Graz, Austria
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3
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Liu Y, Bender SG, Sorigue D, Diaz DJ, Ellington AD, Mann G, Allmendinger S, Hyster TK. Asymmetric Synthesis of α-Chloroamides via Photoenzymatic Hydroalkylation of Olefins. J Am Chem Soc 2024; 146:7191-7197. [PMID: 38442365 DOI: 10.1021/jacs.4c00927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Photoenzymatic intermolecular hydroalkylations of olefins are highly enantioselective for chiral centers formed during radical termination but poorly selective for centers set in the C-C bond-forming event. Here, we report the evolution of a flavin-dependent "ene"-reductase to catalyze the coupling of α,α-dichloroamides with alkenes to afford α-chloroamides in good yield with excellent chemo- and stereoselectivity. These products can serve as linchpins in the synthesis of pharmaceutically valuable motifs. Mechanistic studies indicate that radical formation occurs by exciting a charge-transfer complex templated by the protein. Precise control over the orientation of molecules within the charge-transfer complex potentially accounts for the observed stereoselectivity. The work expands the types of motifs that can be prepared using photoenzymatic catalysis.
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Affiliation(s)
- Yi Liu
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Sophie G Bender
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Damien Sorigue
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Aix-Marseille University, CEA, CNRS, Institute of Biosciences and Biotechnologies, BIAM Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Daniel J Diaz
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
- Institute for Foundations of Machine Learning, University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew D Ellington
- Department of Molecular Bioscience, University of Texas at Austin, Austin, Texas 78712, United States
| | - Greg Mann
- Novartis Pharm. AG, Basel 4002, Switzerland
| | | | - Todd K Hyster
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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4
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d'Oelsnitz S, Diaz DJ, Kim W, Acosta DJ, Dangerfield TL, Schechter MW, Minus MB, Howard JR, Do H, Loy JM, Alper HS, Zhang YJ, Ellington AD. Biosensor and machine learning-aided engineering of an amaryllidaceae enzyme. Nat Commun 2024; 15:2084. [PMID: 38453941 PMCID: PMC10920890 DOI: 10.1038/s41467-024-46356-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 02/22/2024] [Indexed: 03/09/2024] Open
Abstract
A major challenge to achieving industry-scale biomanufacturing of therapeutic alkaloids is the slow process of biocatalyst engineering. Amaryllidaceae alkaloids, such as the Alzheimer's medication galantamine, are complex plant secondary metabolites with recognized therapeutic value. Due to their difficult synthesis they are regularly sourced by extraction and purification from the low-yielding daffodil Narcissus pseudonarcissus. Here, we propose an efficient biosensor-machine learning technology stack for biocatalyst development, which we apply to engineer an Amaryllidaceae enzyme in Escherichia coli. Directed evolution is used to develop a highly sensitive (EC50 = 20 μM) and specific biosensor for the key Amaryllidaceae alkaloid branchpoint 4'-O-methylnorbelladine. A structure-based residual neural network (MutComputeX) is subsequently developed and used to generate activity-enriched variants of a plant methyltransferase, which are rapidly screened with the biosensor. Functional enzyme variants are identified that yield a 60% improvement in product titer, 2-fold higher catalytic activity, and 3-fold lower off-product regioisomer formation. A solved crystal structure elucidates the mechanism behind key beneficial mutations.
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Affiliation(s)
- Simon d'Oelsnitz
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
- Synthetic Biology HIVE, Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Daniel J Diaz
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
- Institute for Foundations of Machine Learning, University of Texas at Austin, Austin, TX, 78712, USA
| | - Wantae Kim
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, 78712, USA
| | - Daniel J Acosta
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Tyler L Dangerfield
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Mason W Schechter
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Matthew B Minus
- Department of Chemistry, Prairie View A&M University, 100 University Dr, Prairie View, TX, 77446, USA
| | - James R Howard
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Hannah Do
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - James M Loy
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Hal S Alper
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, 78712, USA
| | - Y Jessie Zhang
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Andrew D Ellington
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
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5
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Ngo PHT, Ishida S, Busogi BB, Do H, Ledesma MA, Kar S, Ellington A. Changes in Coding and Efficiency through Modular Modifications to a One Pot PURE System for In Vitro Transcription and Translation. ACS Synth Biol 2023; 12:3771-3777. [PMID: 38050859 DOI: 10.1021/acssynbio.3c00461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The incorporation of unnatural amino acids is an attractive method for improving or bringing new and novel functions in peptides and proteins. Cell-free protein synthesis using the Protein Synthesis Using Recombinant Elements (PURE) system is an attractive platform for efficient unnatural amino acid incorporation. In this work, we further adapted and modified the One Pot PURE to obtain a robust and modular system for enzymatic single-site-specific incorporation of an unnatural amino acid. We demonstrated the flexibility of this system through the introduction of two different orthogonal aminoacyl tRNA synthetase:tRNA pairs that suppressed two distinctive stop codons in separate reaction mixtures.
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Affiliation(s)
- Phuoc H T Ngo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Satoshi Ishida
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Bianca B Busogi
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hannah Do
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Maximiliano A Ledesma
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Shaunak Kar
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew Ellington
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
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6
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Kouba P, Kohout P, Haddadi F, Bushuiev A, Samusevich R, Sedlar J, Damborsky J, Pluskal T, Sivic J, Mazurenko S. Machine Learning-Guided Protein Engineering. ACS Catal 2023; 13:13863-13895. [PMID: 37942269 PMCID: PMC10629210 DOI: 10.1021/acscatal.3c02743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/20/2023] [Indexed: 11/10/2023]
Abstract
Recent progress in engineering highly promising biocatalysts has increasingly involved machine learning methods. These methods leverage existing experimental and simulation data to aid in the discovery and annotation of promising enzymes, as well as in suggesting beneficial mutations for improving known targets. The field of machine learning for protein engineering is gathering steam, driven by recent success stories and notable progress in other areas. It already encompasses ambitious tasks such as understanding and predicting protein structure and function, catalytic efficiency, enantioselectivity, protein dynamics, stability, solubility, aggregation, and more. Nonetheless, the field is still evolving, with many challenges to overcome and questions to address. In this Perspective, we provide an overview of ongoing trends in this domain, highlight recent case studies, and examine the current limitations of machine learning-based methods. We emphasize the crucial importance of thorough experimental validation of emerging models before their use for rational protein design. We present our opinions on the fundamental problems and outline the potential directions for future research.
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Affiliation(s)
- Petr Kouba
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
Republic
- Czech Institute
of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
- Faculty of
Electrical Engineering, Czech Technical
University in Prague, Technicka 2, 166 27 Prague 6, Czech Republic
| | - Pavel Kohout
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
Republic
- International
Clinical Research Center, St. Anne’s
University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Faraneh Haddadi
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
Republic
- International
Clinical Research Center, St. Anne’s
University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Anton Bushuiev
- Czech Institute
of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
| | - Raman Samusevich
- Czech Institute
of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 160 00 Prague 6, Czech Republic
| | - Jiri Sedlar
- Czech Institute
of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
Republic
- International
Clinical Research Center, St. Anne’s
University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Tomas Pluskal
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 160 00 Prague 6, Czech Republic
| | - Josef Sivic
- Czech Institute
of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
| | - Stanislav Mazurenko
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech
Republic
- International
Clinical Research Center, St. Anne’s
University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
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7
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Li J, Li Y, Li Y, Ma Y, Xu W, Wang J. An enhanced activity and thermostability of chimeric Bst DNA polymerase for isothermal amplification applications. Appl Microbiol Biotechnol 2023; 107:6527-6540. [PMID: 37672070 DOI: 10.1007/s00253-023-12751-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/31/2023] [Accepted: 08/28/2023] [Indexed: 09/07/2023]
Abstract
Loop-mediated isothermal amplification (LAMP) is a widely used method for clinical diagnosis, customs quarantine, and disease prevention. However, the low catalytic activity of Bst DNA polymerase has made it challenging to develop rapid and reliable point-of-care testing. Herein, we developed a series of Bst DNA polymerase mutants with enhanced activity by predicting and analyzing the activity sites. Among these mutants, single mutants K431D and K431E showed a 1.93- and 2.03-fold increase in catalytic efficiency, respectively. We also created a chimeric protein by fusing the DNA-binding domain of DNA ligase from Pyrococcus abyssi (DBD), namely DBD-K431E, which enabled real-time LAMP at high temperatures up to 73 ℃ and remained active after heating at 70 ℃ for 8 h. The chimeric DBD-K431E remained active in the presence of 50 U/mL heparin, 10% ethanol, and up to 100 mM NaCl, and showed higher activity in 110 mM (NH4)2SO4, 110 mM KCl, and 12 mM MgSO4. Notably, it generated a fluorescence signal during the detection of Salmonella typhimurium at 2 × 102 ag/μL of genomic DNA and 1.24 CFU/mL of bacterial colony, outperforming the wild type and the commercial counterpart Bst 2.0. Our results suggest that the DBD-K431E variant could be a promising tool for general molecular biology research and clinical diagnostics. KEY POINTS: • Residue K431 is probably a key site of Bst DNA polymerase activity • The chimeric DBD-K431E is more inhibitor tolerant and thermostable than Bst-LF • The DBD-K431E variant can detect Salmonella typhimurium at 102 ag/μL or 100 CFU/mL.
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Affiliation(s)
- Jiaxuan Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yang Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yanmei Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yi Ma
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Wei Xu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China.
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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8
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Kunka A, Marques SM, Havlasek M, Vasina M, Velatova N, Cengelova L, Kovar D, Damborsky J, Marek M, Bednar D, Prokop Z. Advancing Enzyme's Stability and Catalytic Efficiency through Synergy of Force-Field Calculations, Evolutionary Analysis, and Machine Learning. ACS Catal 2023; 13:12506-12518. [PMID: 37822856 PMCID: PMC10563018 DOI: 10.1021/acscatal.3c02575] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/24/2023] [Indexed: 10/13/2023]
Abstract
Thermostability is an essential requirement for the use of enzymes in the bioindustry. Here, we compare different protein stabilization strategies using a challenging target, a stable haloalkane dehalogenase DhaA115. We observe better performance of automated stabilization platforms FireProt and PROSS in designing multiple-point mutations over the introduction of disulfide bonds and strengthening the intra- and the inter-domain contacts by in silico saturation mutagenesis. We reveal that the performance of automated stabilization platforms was still compromised due to the introduction of some destabilizing mutations. Notably, we show that their prediction accuracy can be improved by applying manual curation or machine learning for the removal of potentially destabilizing mutations, yielding highly stable haloalkane dehalogenases with enhanced catalytic properties. A comparison of crystallographic structures revealed that current stabilization rounds were not accompanied by large backbone re-arrangements previously observed during the engineering stability of DhaA115. Stabilization was achieved by improving local contacts including protein-water interactions. Our study provides guidance for further improvement of automated structure-based computational tools for protein stabilization.
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Affiliation(s)
- Antonin Kunka
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Sérgio M. Marques
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Martin Havlasek
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
| | - Michal Vasina
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Nikola Velatova
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
| | - Lucia Cengelova
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
| | - David Kovar
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Martin Marek
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - David Bednar
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
| | - Zbynek Prokop
- Loschmidt
Laboratories, Department of Experimental Biology and RECETOX, Faculty
of Science, Masaryk University, Brno 601 77, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Brno 601 77, Czech Republic
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9
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Oscorbin I, Filipenko M. Bst polymerase - a humble relative of Taq polymerase. Comput Struct Biotechnol J 2023; 21:4519-4535. [PMID: 37767105 PMCID: PMC10520511 DOI: 10.1016/j.csbj.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/31/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
DNA polymerases are a superfamily of enzymes synthesizing DNA using DNA as a template. They are essential for nucleic acid metabolism and for DNA replication and repair. Modern biotechnology and molecular diagnostics rely heavily on DNA polymerases in analyzing nucleic acids. Among a variety of discovered DNA polymerases, Bst polymerase, a large fragment of DNA polymerase I from Geobacillus stearothermophilus, is one of the most commonly used but is not as well studied as Taq polymerase. The ability of Bst polymerase to displace an upstream DNA strand during synthesis, coupled with its moderate thermal stability, has provided the basis for several isothermal DNA amplification methods, including LAMP, WGA, RCA, and many others. Bst polymerase is one of the key components defining the robustness and analytical characteristics of diagnostic test systems based on isothermal amplification. Here, we present an overview of the biochemical and structural features of Bst polymerase and provide information on its mutated analogs.
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Affiliation(s)
- Igor Oscorbin
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Maxim Filipenko
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
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10
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Kulikova AV, Diaz DJ, Chen T, Cole TJ, Ellington AD, Wilke CO. Two sequence- and two structure-based ML models have learned different aspects of protein biochemistry. Sci Rep 2023; 13:13280. [PMID: 37587128 PMCID: PMC10432456 DOI: 10.1038/s41598-023-40247-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023] Open
Abstract
Deep learning models are seeing increased use as methods to predict mutational effects or allowed mutations in proteins. The models commonly used for these purposes include large language models (LLMs) and 3D Convolutional Neural Networks (CNNs). These two model types have very different architectures and are commonly trained on different representations of proteins. LLMs make use of the transformer architecture and are trained purely on protein sequences whereas 3D CNNs are trained on voxelized representations of local protein structure. While comparable overall prediction accuracies have been reported for both types of models, it is not known to what extent these models make comparable specific predictions and/or generalize protein biochemistry in similar ways. Here, we perform a systematic comparison of two LLMs and two structure-based models (CNNs) and show that the different model types have distinct strengths and weaknesses. The overall prediction accuracies are largely uncorrelated between the sequence- and structure-based models. Overall, the two structure-based models are better at predicting buried aliphatic and hydrophobic residues whereas the two LLMs are better at predicting solvent-exposed polar and charged amino acids. Finally, we find that a combined model that takes the individual model predictions as input can leverage these individual model strengths and results in significantly improved overall prediction accuracy.
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Affiliation(s)
- Anastasiya V Kulikova
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- The Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA
| | - Daniel J Diaz
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA
- The Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA
- Institute for Foundations of Machine Learning (IFML), The University of Texas at Austin, Austin, TX, USA
| | - Tianlong Chen
- Institute for Foundations of Machine Learning (IFML), The University of Texas at Austin, Austin, TX, USA
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA
| | - T Jeffrey Cole
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Andrew D Ellington
- The Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA
| | - Claus O Wilke
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA.
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11
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Kulikova AV, Diaz DJ, Chen T, Jeffrey Cole T, Ellington AD, Wilke CO. Two sequence- and two structure-based ML models have learned different aspects of protein biochemistry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.533508. [PMID: 36993648 PMCID: PMC10055221 DOI: 10.1101/2023.03.20.533508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Deep learning models are seeing increased use as methods to predict mutational effects or allowed mutations in proteins. The models commonly used for these purposes include large language models (LLMs) and 3D Convolutional Neural Networks (CNNs). These two model types have very different architectures and are commonly trained on different representations of proteins. LLMs make use of the transformer architecture and are trained purely on protein sequences whereas 3D CNNs are trained on voxelized representations of local protein structure. While comparable overall prediction accuracies have been reported for both types of models, it is not known to what extent these models make comparable specific predictions and/or generalize protein biochemistry in similar ways. Here, we perform a systematic comparison of two LLMs and two structure-based models (CNNs) and show that the different model types have distinct strengths and weaknesses. The overall prediction accuracies are largely uncorrelated between the sequence- and structure-based models. Overall, the two structure-based models are better at predicting buried aliphatic and hydrophobic residues whereas the two LLMs are better at predicting solvent-exposed polar and charged amino acids. Finally, we find that a combined model that takes the individual model predictions as input can leverage these individual model strengths and results in significantly improved overall prediction accuracy.
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Affiliation(s)
- Anastasiya V. Kulikova
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
- Center for Systems and Synthetic Biology, The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Daniel J. Diaz
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA
- Center for Systems and Synthetic Biology, The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Institute for Foundations of Machine Learning (IFML), The University of Texas at Austin, Austin, TX, USA
| | - Tianlong Chen
- Institute for Foundations of Machine Learning (IFML), The University of Texas at Austin, Austin, TX, USA
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA
| | - T. Jeffrey Cole
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - Andrew D. Ellington
- Center for Systems and Synthetic Biology, The Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Claus O. Wilke
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
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12
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Ordóñez CD, Redrejo-Rodríguez M. DNA Polymerases for Whole Genome Amplification: Considerations and Future Directions. Int J Mol Sci 2023; 24:ijms24119331. [PMID: 37298280 DOI: 10.3390/ijms24119331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
In the same way that specialized DNA polymerases (DNAPs) replicate cellular and viral genomes, only a handful of dedicated proteins from various natural origins as well as engineered versions are appropriate for competent exponential amplification of whole genomes and metagenomes (WGA). Different applications have led to the development of diverse protocols, based on various DNAPs. Isothermal WGA is currently widely used due to the high performance of Φ29 DNA polymerase, but PCR-based methods are also available and can provide competent amplification of certain samples. Replication fidelity and processivity must be considered when selecting a suitable enzyme for WGA. However, other properties, such as thermostability, capacity to couple replication, and double helix unwinding, or the ability to maintain DNA replication opposite to damaged bases, are also very relevant for some applications. In this review, we provide an overview of the different properties of DNAPs widely used in WGA and discuss their limitations and future research directions.
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Affiliation(s)
- Carlos D Ordóñez
- CIC bioGUNE, Bizkaia Science and Technology Park, Building 800, 48160 Derio, Spain
| | - Modesto Redrejo-Rodríguez
- Department of Biochemistry, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, 28029 Madrid, Spain
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13
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Wang Y, Zhang L, Shen Y, Yu EYW, Ding X. Nested Phosphorothioated Hybrid Primer-Mediated Isothermal Amplification for Specific and Dye-Based Subattomolar Nucleic Acid Detection at Low Temperatures. ACS Sens 2023; 8:1261-1271. [PMID: 36867102 DOI: 10.1021/acssensors.2c02754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Developing dye-based isothermal nucleic acid amplification (INAA) at low temperatures such as 37 °C remains a technical challenge. Here, we describe a nested phosphorothioated (PS) hybrid primer-mediated isothermal amplification (NPSA) assay which only utilizes EvaGreen (a DNA-binding dye) to achieve specific and dye-based subattomolar nucleic acid detection at 37 °C. The success of low-temperature NPSA essentially depends on employing Bacillus smithii DNA polymerase, a strand-displacing DNA polymerase with wide range of activation temperature. However, the NPSA's high efficiency entails nested PS-modified hybrid primers and the additives of urea and T4 Gene 32 Protein. To address the inhibition of urea on reverse transcription (RT), one-tube two-stage recombinase-aided RT-NPSA (rRT-NPSA) is established. By targeting human Kirsten rat sarcoma viral (KRAS) oncogene, NPSA (rRT-NPSA) stably detects 0.2 aM of KRAS gene (mRNA) within 90 (60) min. In addition, rRT-NPSA possesses subattomolar sensitivity to detect human ribosomal protein L13 mRNA. The NPSA/rRT-NPSA assays are also validated to obtain consistent results with PCR/RT-PCR methods on qualitatively detecting DNA/mRNA targets extracted from cultured cells and clinical samples. As a dye-based, low-temperature INAA method, NPSA inherently facilitates the development of miniaturized diagnostic biosensors.
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Affiliation(s)
- Yaru Wang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
- Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China
| | - Lanxiang Zhang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
- Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China
| | - Yuqing Shen
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
- Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China
| | - Evan Yi-Wen Yu
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
- Department of Epidemiology & Biostatistics, School of Public Health, Southeast University, Nanjing 210009, China
| | - Xiong Ding
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
- Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China
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14
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Dangerfield TL, Paik I, Bhadra S, Johnson KA, Ellington A. Kinetics of elementary steps in loop-mediated isothermal amplification (LAMP) show that strand invasion during initiation is rate-limiting. Nucleic Acids Res 2023; 51:488-499. [PMID: 36583345 PMCID: PMC9841402 DOI: 10.1093/nar/gkac1221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 12/31/2022] Open
Abstract
Loop-mediated isothermal amplification (LAMP) has proven to be easier to implement than PCR for point-of-care diagnostic tests. However, the underlying mechanism of LAMP is complicated and the kinetics of the major steps in LAMP have not been fully elucidated, which prevents rational improvements in assay development. Here we present our work to characterize the kinetics of the elementary steps in LAMP and show that: (i) strand invasion / initiation is the rate-limiting step in the LAMP reaction; (ii) the loop primer plays an important role in accelerating the rate of initiation and does not function solely during the exponential amplification phase and (iii) strand displacement synthesis by Bst-LF polymerase is relatively fast (125 nt/s) and processive on both linear and hairpin templates, although with some interruptions on high GC content templates. Building on these data, we were able to develop a kinetic model that relates the individual kinetic experiments to the bulk LAMP reaction. The assays developed here provide important insights into the mechanism of LAMP, and the overall model should be crucial in engineering more sensitive and faster LAMP reactions. The kinetic methods we employ should likely prove useful with other isothermal DNA amplification methods.
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Affiliation(s)
- Tyler L Dangerfield
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Inyup Paik
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Sanchita Bhadra
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Kenneth A Johnson
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Andrew D Ellington
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
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15
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Shirshikov FV, Bespyatykh JA. Loop-Mediated Isothermal Amplification: From Theory to Practice. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022; 48:1159-1174. [PMID: 36590469 PMCID: PMC9788664 DOI: 10.1134/s106816202206022x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/01/2022] [Accepted: 06/17/2022] [Indexed: 12/24/2022]
Abstract
Increasing the accuracy of pathogen identification and reducing the duration of analysis remain relevant for modern molecular diagnostics up to this day. In laboratory and clinical practice, detection of pathogens mostly relies on methods of nucleic acid amplification, among which the polymerase chain reaction (PCR) is considered the "gold standard." Nevertheless, in some cases, isothermal amplification methods act as an alternative to PCR diagnostics. Upon more than thirty years of the development of isothermal DNA synthesis, the appearance of loop-mediated isothermal amplification (LAMP) has enabled new directions of in-field diagnostics of bacterial and viral infections. This review examines the key characteristics of the LAMP method and corresponding features in practice. We discuss the structure of LAMP amplicons with single-stranded loops, which have the sites for primer annealing under isothermal conditions. The latest achievements in the modification of the LAMP method are analyzed, which allow considering it as a unique platform for creating the next-generation diagnostic assays.
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Affiliation(s)
- F. V. Shirshikov
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435 Moscow, Russia
| | - J. A. Bespyatykh
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435 Moscow, Russia
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16
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Wang G, Du Y, Ma X, Ye F, Qin Y, Wang Y, Xiang Y, Tao R, Chen T. Thermophilic Nucleic Acid Polymerases and Their Application in Xenobiology. Int J Mol Sci 2022; 23:ijms232314969. [PMID: 36499296 PMCID: PMC9738464 DOI: 10.3390/ijms232314969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 12/02/2022] Open
Abstract
Thermophilic nucleic acid polymerases, isolated from organisms that thrive in extremely hot environments, possess great DNA/RNA synthesis activities under high temperatures. These enzymes play indispensable roles in central life activities involved in DNA replication and repair, as well as RNA transcription, and have already been widely used in bioengineering, biotechnology, and biomedicine. Xeno nucleic acids (XNAs), which are analogs of DNA/RNA with unnatural moieties, have been developed as new carriers of genetic information in the past decades, which contributed to the fast development of a field called xenobiology. The broad application of these XNA molecules in the production of novel drugs, materials, and catalysts greatly relies on the capability of enzymatic synthesis, reverse transcription, and amplification of them, which have been partially achieved with natural or artificially tailored thermophilic nucleic acid polymerases. In this review, we first systematically summarize representative thermophilic and hyperthermophilic polymerases that have been extensively studied and utilized, followed by the introduction of methods and approaches in the engineering of these polymerases for the efficient synthesis, reverse transcription, and amplification of XNAs. The application of XNAs facilitated by these polymerases and their mutants is then discussed. In the end, a perspective for the future direction of further development and application of unnatural nucleic acid polymerases is provided.
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17
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Paik I, Bhadra S, Ellington AD. Charge Engineering Improves the Performance of Bst DNA Polymerase Fusions. ACS Synth Biol 2022; 11:1488-1496. [PMID: 35320674 DOI: 10.1021/acssynbio.1c00559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The charge states of proteins can greatly influence their stabilities and interactions with substrates, and the addition of multiple charges (supercharging) has been shown to be a successful approach for engineering protein stability and function. The addition of a fast-folding fusion domain to the Bacillus stearothermophilus DNA polymerase improved its functionality in isothermal amplification assays, and further charge engineering of this domain has increased both protein stability and diagnostics performance. When combined with mutations that stabilize the core of the protein, the charge-engineered fusion domain leads to the ability to carry out loop-mediated isothermal amplification (LAMP) at temperatures up to 74° C or in the presence of high concentrations of urea, with detection times under 10 min. Adding both positive and negative charges to the fusion domain led to changes in the relative reverse transcriptase and DNA polymerase activities of the polymerase. Overall, the development of a modular fusion domain whose charged surface can be modified at will should prove to be of use in the engineering of other polymerases and, in general, may prove useful for protein stabilization.
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Affiliation(s)
- Inyup Paik
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sanchita Bhadra
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew D. Ellington
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
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18
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Bhadra S, Paik I, Torres JA, Fadanka S, Gandini C, Akligoh H, Molloy J, Ellington AD. Preparation and Use of Cellular Reagents: A Low-resource Molecular Biology Reagent Platform. Curr Protoc 2022; 2:e387. [PMID: 35263038 PMCID: PMC9094432 DOI: 10.1002/cpz1.387] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein reagents are indispensable for most molecular and synthetic biology procedures. Most conventional protocols rely on highly purified protein reagents that require considerable expertise, time, and infrastructure to produce. In consequence, most proteins are acquired from commercial sources, reagent expense is often high, and accessibility may be hampered by shipping delays, customs barriers, geopolitical constraints, and the need for a constant cold chain. Such limitations to the widespread availability of protein reagents, in turn, limit the expansion and adoption of molecular biology methods in research, education, and technology development and application. Here, we describe protocols for producing a low-resource and locally sustainable reagent delivery system, termed "cellular reagents," in which bacteria engineered to overexpress proteins of interest are dried and can then be used directly as reagent packets in numerous molecular biology reactions, without the need for protein purification or a constant cold chain. As an example of their application, we describe the execution of polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) using cellular reagents, detailing how to replace pure protein reagents with optimal amounts of rehydrated cellular reagents. We additionally describe a do-it-yourself fluorescence visualization device for using these cellular reagents in common molecular biology applications. The methods presented in this article can be used for low-cost, on-site production of commonly used molecular biology reagents (including DNA and RNA polymerases, reverse transcriptases, and ligases) with minimal instrumentation and expertise, and without the need for protein purification. Consequently, these methods should generally make molecular biology reagents more affordable and accessible. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Preparation of cellular reagents Alternate Protocol 1: Preparation of lyophilized cellular reagents Alternate Protocol 2: Evaluation of bacterial culture growth via comparison to McFarland turbidity standards Support Protocol 1: SDS-PAGE for protein expression analysis of cellular reagents Basic Protocol 2: Using Taq DNA polymerase cellular reagents for PCR Basic Protocol 3: Using Br512 DNA polymerase cellular reagents for loop-mediated isothermal amplification (LAMP) Support Protocol 2: Building a fluorescence visualization device.
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Affiliation(s)
- Sanchita Bhadra
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, United States of America,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, United States of America,Corresponding authors: ,
| | - Inyup Paik
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, United States of America,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Jose-Angel Torres
- Freshman Research Initiative, DIY Diagnostics Stream, The University of Texas at Austin, Austin, Texas, United States of America
| | | | - Chiara Gandini
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Harry Akligoh
- Hive Biolab, Hse 49, SE 29056 Drive, 2nd Turn Behind Mizpah School, Kentinkrono, Kumasi, Ghana
| | - Jenny Molloy
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Andrew D. Ellington
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, United States of America,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, United States of America,Corresponding authors: ,
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19
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Clinical validation of engineered CRISPR/Cas12a for rapid SARS-CoV-2 detection. COMMUNICATIONS MEDICINE 2022; 2:7. [PMID: 35603267 PMCID: PMC9053293 DOI: 10.1038/s43856-021-00066-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 11/30/2021] [Indexed: 12/26/2022] Open
Abstract
Background The coronavirus disease (COVID-19) caused by SARS-CoV-2 has swept through the globe at an unprecedented rate. CRISPR-based detection technologies have emerged as a rapid and affordable platform that can shape the future of diagnostics. Methods We developed ENHANCEv2 that is composed of a chimeric guide RNA, a modified LbCas12a enzyme, and a dual reporter construct to improve the previously reported ENHANCE system. We validated both ENHANCE and ENHANCEv2 using 62 nasopharyngeal swabs and compared the results to RT-qPCR. We created a lyophilized version of ENHANCEv2 and characterized its detection capability and stability. Results Here we demonstrate that when coupled with an RT-LAMP step, ENHANCE detects COVID-19 samples down to a few copies with 95% accuracy while maintaining a high specificity towards various isolates of SARS-CoV-2 against 31 highly similar and common respiratory pathogens. ENHANCE works robustly in a wide range of magnesium concentrations (3 mM-13 mM), allowing for further assay optimization. Our clinical validation results for both ENHANCE and ENHANCEv2 show 60/62 (96.7%) sample agreement with RT-qPCR results while only using 5 µL of sample and 20 minutes of CRISPR reaction. We show that the lateral flow assay using paper-based strips displays 100% agreement with the fluorescence-based reporter assay during clinical validation. Finally, we demonstrate that a lyophilized version of ENHANCEv2 shows high sensitivity and specificity for SARS-CoV-2 detection while reducing the CRISPR reaction time to as low as 3 minutes while maintaining its detection capability for several weeks upon storage at room temperature. Conclusions CRISPR-based diagnostic platforms offer many advantages as compared to conventional qPCR-based detection methods. Our work here provides clinical validation of ENHANCE and its improved form ENHANCEv2 for the detection of COVID-19. Nguyen et al. describe the clinical validation of the ENHANCE system, a method to detect SARS-CoV-2 based on engineered crRNAs for Cas12a and preceded by an RT-LAMP amplification step. Authors also describe the development and clinical validation of a version of this system, ENHANCEv2, that can be lyophilized and that uses another mutated Cas12a for further signal amplification. The COVID-19 pandemic has underscored the need for rapid and accurate tests to detect SARS-CoV-2 infection. The tests commonly used have limitations, and a detection system based on CRISPR technology could offer a useful alternative. CRISPR is a technology derived from bacteria that can specifically detect pieces of DNA. We have previously developed ENHANCE, a detection system that converts the SARS-CoV-2 genetic material into DNA that is then detected by an engineered CRISPR technology. Here, we develop an improved version of this method, ENHANCEv2, that has an extended shelf life and less need for refrigeration, facilitating transportation of the components required for the test and its use. We show that both ENHANCE and ENHACEv2 can quickly and accurately detect SARS-CoV-2 in swabs from infected people. This is a step towards having more versatile tools to detect SARS-CoV-2 infection quickly and accurately.
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