1
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Michel F, Romero‐Romero S, Höcker B. Retracing the evolution of a modern periplasmic binding protein. Protein Sci 2023; 32:e4793. [PMID: 37788980 PMCID: PMC10601554 DOI: 10.1002/pro.4793] [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: 07/10/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/05/2023]
Abstract
Investigating the evolution of structural features in modern multidomain proteins helps to understand their immense diversity and functional versatility. The class of periplasmic binding proteins (PBPs) offers an opportunity to interrogate one of the main processes driving diversification: the duplication and fusion of protein sequences to generate new architectures. The symmetry of their two-lobed topology, their mechanism of binding, and the organization of their operon structure led to the hypothesis that PBPs arose through a duplication and fusion event of a single common ancestor. To investigate this claim, we set out to reverse the evolutionary process and recreate the structural equivalent of a single-lobed progenitor using ribose-binding protein (RBP) as our model. We found that this modern PBP can be deconstructed into its lobes, producing two proteins that represent possible progenitor halves. The isolated halves of RBP are well folded and monomeric proteins, albeit with a lower thermostability, and do not retain the original binding function. However, the two entities readily form a heterodimer in vitro and in-cell. The x-ray structure of the heterodimer closely resembles the parental protein. Moreover, the binding function is fully regained upon formation of the heterodimer with a ligand affinity similar to that observed in the modern RBP. This highlights how a duplication event could have given rise to a stable and functional PBP-like fold and provides insights into how more complex functional structures can evolve from simpler molecular components.
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Affiliation(s)
- Florian Michel
- Department of BiochemistryUniversity of BayreuthBayreuthGermany
| | | | - Birte Höcker
- Department of BiochemistryUniversity of BayreuthBayreuthGermany
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2
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Allert MJ, Kumar S, Wang Y, Beese LS, Hellinga HW. Chromophore carbonyl twisting in fluorescent biosensors encodes direct readout of protein conformations with multicolor switching. Commun Chem 2023; 6:168. [PMID: 37598249 PMCID: PMC10439942 DOI: 10.1038/s42004-023-00982-7] [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: 05/31/2023] [Accepted: 08/11/2023] [Indexed: 08/21/2023] Open
Abstract
Fluorescent labeling of proteins is a powerful tool for probing structure-function relationships with many biosensing applications. Structure-based rules for systematically designing fluorescent biosensors require understanding ligand-mediated fluorescent response mechanisms which can be challenging to establish. We installed thiol-reactive derivatives of the naphthalene-based fluorophore Prodan into bacterial periplasmic glucose-binding proteins. Glucose binding elicited paired color exchanges in the excited and ground states of these conjugates. X-ray structures and mutagenesis studies established that glucose-mediated color switching arises from steric interactions that couple protein conformational changes to twisting of the Prodan carbonyl relative to its naphthalene plane. Mutations of residues contacting the carbonyl can optimize color switching by altering fluorophore conformational equilibria in the apo and glucose-bound proteins. A commonly accepted view is that Prodan derivatives report on protein conformations via solvatochromic effects due to changes in the dielectric of their local environment. Here we show that instead Prodan carbonyl twisting controls color switching. These insights enable structure-based biosensor design by coupling ligand-mediated protein conformational changes to internal chromophore twists through specific steric interactions between fluorophore and protein.
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Affiliation(s)
- Malin J Allert
- Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA
| | - Shivesh Kumar
- Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - You Wang
- Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA
| | - Lorena S Beese
- Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA
| | - Homme W Hellinga
- Department of Biochemistry, Duke University Medical Center, Durham, NC, 27710, USA.
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3
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Allert MJ, Hellinga HW. Discovery of Thermostable, Fluorescently Responsive Glucose Biosensors by Structure-Assisted Function Extrapolation. Biochemistry 2022; 61:276-293. [PMID: 35084821 DOI: 10.1021/acs.biochem.1c00738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Accurate assignment of protein function from sequence remains a fascinating and difficult challenge. The periplasmic-binding protein (PBP) superfamily present an interesting case of function prediction because they are both ubiquitous in prokaryotes and tend to diversify through gene duplication "explosions" that can lead to large numbers of paralogs in a genome. An engineered version of the moderately thermostable glucose-binding PBP from Escherichia coli has been used successfully as a reagentless fluorescent biosensor both in vitro and in vivo. To develop more robust sensors that meet the challenges of real-world applications, we report the discovery of thermostable homologues that retain a glucose-mediated conformationally coupled fluorescence response. Accurately identifying a glucose-binding PBP homologue among closely related paralogs is challenging. We demonstrate that a structure-based method that filters sequences by residues that bind glucose in an archetype structure is highly effective. Using fully sequenced bacterial genomes, we found that this filter reduced high paralog numbers to single hits in a genome, consistent with the accurate separation of glucose binding from other functions. We expressed engineered proteins for eight homologues, chosen to represent different degrees of sequence identity, and tested their glucose-mediated fluorescence responses. We accurately predicted the presence of glucose binding down to 31% sequence identity. We have also successfully identified suitable candidates for next-generation robust, fluorescent glucose sensors.
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Affiliation(s)
- Malin J Allert
- Department of Biochemistry, Duke University Medical Center, Box 3711, Durham, North Carolina 27710, United States
| | - Homme W Hellinga
- Department of Biochemistry, Duke University Medical Center, Box 3711, Durham, North Carolina 27710, United States
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4
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Pang Z, Sokolov M, Kubař T, Elstner M. Unravelling the mechanism of glucose binding in a protein-based fluorescence probe: molecular dynamics simulation with a tailor-made charge model. Phys Chem Chem Phys 2022; 24:2441-2453. [PMID: 35019922 DOI: 10.1039/d1cp03733a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Fluorophores linked to the glucose/galactose-binding protein (GGBP) are a promising class of glucose sensors with potential application in medical devices for diabetes patients. Several different fluorophores at different positions in the protein were tested experimentally so far, but a deeper molecular understanding of their function is still missing. In this work, we use molecular dynamics simulations to investigate the mechanism of glucose binding in the GGBP-Badan triple mutant and make a comparison to the GGBP wild-type protein. The aim is to achieve a detailed molecular understanding of changes in the glucose binding site due to the mutations and their effect on glucose binding. Free simulations give an insight into the changes of the hydrogen-bonding network in the active site and into the mechanisms of glucose binding. Additionally, metadynamics simulations for wild type and mutant unravel the energetics of binding/unbinding in these proteins. Computed free energies for the opening of the binding pocket for the wild-type and the mutant agree well with the experimental data. Further, the simulations also give an insight into the changes of the chromophore conformations upon glucose binding, which can help to understand fluorescence changes. Therefore, the molecular details unravelled in this work may support effective optimisation strategies for the construction of more efficient glucose sensors.
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Affiliation(s)
- Ziwei Pang
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany.
| | - Monja Sokolov
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany.
| | - Tomáš Kubař
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany.
| | - Marcus Elstner
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany. .,Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany
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5
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Photophysical Properties of BADAN Revealed in the Study of GGBP Structural Transitions. Int J Mol Sci 2021; 22:ijms222011113. [PMID: 34681772 PMCID: PMC8540541 DOI: 10.3390/ijms222011113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/06/2021] [Accepted: 10/09/2021] [Indexed: 01/14/2023] Open
Abstract
The fluorescent dye BADAN (6-bromoacetyl-2-dimetylaminonaphtalene) is widely used in various fields of life sciences, however, the photophysical properties of BADAN are not fully understood. The study of the spectral properties of BADAN attached to a number of mutant forms of GGBP, as well as changes in its spectral characteristics during structural changes in proteins, allowed to shed light on the photophysical properties of BADAN. It was shown that spectral properties of BADAN are determined by at least one non-fluorescent and two fluorescent isomers with overlapping absorbing bands. It was found that BADAN fluorescence is determined by the unsolvated "PICT" (planar intramolecular charge transfer state) and solvated "TICT" (twisted intramolecular charge transfer state) excited states. While "TICT" state can be formed both as a result of the "PICT" state solvation and as a result of light absorption by the solvated ground state of the dye. BADAN fluorescence linked to GGBP/H152C apoform is quenched by Trp 183, but this effect is inhibited by glucose intercalation. New details of the changes in the spectral characteristics of BADAN during the unfolding of the protein apo and holoforms have been obtained.
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6
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Ren W, Dokainish HM, Shinobu A, Oshima H, Sugita Y. Unraveling the Coupling between Conformational Changes and Ligand Binding in Ribose Binding Protein Using Multiscale Molecular Dynamics and Free-Energy Calculations. J Phys Chem B 2021; 125:2898-2909. [PMID: 33728914 PMCID: PMC10954230 DOI: 10.1021/acs.jpcb.0c11600] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Conformational changes of proteins upon ligand binding are usually explained in terms of several mechanisms including the induced fit, conformational selection, or their mixtures. Due to the slow time scales, conventional molecular dynamics (cMD) simulations based on the atomistic models cannot easily simulate the open-to-closed conformational transition in proteins. In our previous study, we have developed an enhanced sampling scheme (generalized replica exchange with solute tempering selected surface charged residues: gREST_SSCR) for multidomain proteins and applied it to ligand-mediated conformational changes in the G134R mutant of ribose-binding protein (RBPG134R) in solution. The free-energy landscape (FEL) of RBPG134R in the presence of a ribose at the binding site included the open and closed states and two intermediates, open-like and closed-like forms. Only the open and open-like forms existed in the FEL without a ribose. In the current study, the coupling between the conformational changes and ligand binding is further investigated using coarse-grained MD, multiple atomistic cMD, and free-energy calculations. The ribose is easily dissociated from the binding site of wild-type RBP and RBPG134R in the cMD simulations starting from the open and open-like forms. In contrast, it is stable at the binding site in the simulations from the closed and closed-like forms. The free-energy calculations provide the binding affinities of different structures, supporting the results of cMD simulations. Importantly, cMD simulations from the closed-like structures reveal transitions toward the closed one in the presence of a bound ribose. On the basis of the computational results, we propose a molecular mechanism in which conformational selection and induced fit happen in the first and second halves of the open-to-closed transition in RBP, respectively.
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Affiliation(s)
- Weitong Ren
- Theoretical
Molecular Science Laboratory, RIKEN Cluster
for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hisham M. Dokainish
- Theoretical
Molecular Science Laboratory, RIKEN Cluster
for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Ai Shinobu
- Laboratory
for Biomolecular Function Simulation, RIKEN
Center for Biosystems Dynamics Research, Integrated Innovation Building 7F, 6-7-1 minatojima-minamimachi,
Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Hiraku Oshima
- Laboratory
for Biomolecular Function Simulation, RIKEN
Center for Biosystems Dynamics Research, Integrated Innovation Building 7F, 6-7-1 minatojima-minamimachi,
Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Yuji Sugita
- Theoretical
Molecular Science Laboratory, RIKEN Cluster
for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Computational
Biophysics Research Team, RIKEN Center for
Computational Science, Integrated Innovation Building 7F, 6-7-1 minatojima-minamimachi,
Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Laboratory
for Biomolecular Function Simulation, RIKEN
Center for Biosystems Dynamics Research, Integrated Innovation Building 7F, 6-7-1 minatojima-minamimachi,
Chuo-ku, Kobe, Hyogo 650-0047, Japan
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7
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Yang M, Tang Y, Weng J, Liu Z, Wang W. The Role of Calcium in Regulating the Conformational Dynamics of d-Galactose/d-Glucose-Binding Protein Revealed by Markov State Model Analysis. J Chem Inf Model 2021; 61:891-900. [PMID: 33445873 DOI: 10.1021/acs.jcim.0c01119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The d-glucose/d-galactose-binding protein (GGBP) from Escherichia coli is a substrate-binding protein (SBP) associated with sugar transport and chemotaxis. It is also a calcium-binding protein, which makes it unique in the SBP family. However, the functional importance of Ca2+ binding is not fully understood. Here, the calcium-dependent properties of GGBP were explored by all-atom molecular dynamics simulations and Markov state model (MSM) analysis as well as single-molecule Förster resonance energy transfer (smFRET) measurements. In agreement with previous experimental studies, we observed the structure stabilization effect of Ca2+ binding on the C-terminal domain of GGBP, especially the Ca2+-binding site. Interestingly, the MSMs of calcium-depleted GGBP and calcium-bound GGBP (GGBP/Ca2+) demonstrate that Ca2+ greatly stabilizes the open conformation, and smFRET measurements confirmed this result. Further analysis reveals that Ca2+ binding disturbs the local hydrogen bonding interactions and the conformational dynamics of the hinge region, thereby weakening the long-range interdomain correlations to favor the open conformation. These results suggest an active regulatory role of Ca2+ binding in GGBP, which finely tunes the conformational distribution. The work sheds new light on the study of calcium-binding proteins in prokaryotes.
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Affiliation(s)
- Maohua Yang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Yegen Tang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Jingwei Weng
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Zhijun Liu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Wenning Wang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
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8
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Martínez JD, Manzano AI, Calviño E, Diego AD, Rodriguez de Francisco B, Romanò C, Oscarson S, Millet O, Gabius HJ, Jiménez-Barbero J, Cañada FJ. Fluorinated Carbohydrates as Lectin Ligands: Simultaneous Screening of a Monosaccharide Library and Chemical Mapping by 19F NMR Spectroscopy. J Org Chem 2020; 85:16072-16081. [PMID: 33258593 PMCID: PMC7773211 DOI: 10.1021/acs.joc.0c01830] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Indexed: 02/06/2023]
Abstract
Molecular recognition of carbohydrates is a key step in essential biological processes. Carbohydrate receptors can distinguish monosaccharides even if they only differ in a single aspect of the orientation of the hydroxyl groups or harbor subtle chemical modifications. Hydroxyl-by-fluorine substitution has proven its merits for chemically mapping the importance of hydroxyl groups in carbohydrate-receptor interactions. 19F NMR spectroscopy could thus be adapted to allow contact mapping together with screening in compound mixtures. Using a library of fluorinated glucose (Glc), mannose (Man), and galactose (Gal) derived by systematically exchanging every hydroxyl group by a fluorine atom, we developed a strategy combining chemical mapping and 19F NMR T2 filtering-based screening. By testing this strategy on the proof-of-principle level with a library of 13 fluorinated monosaccharides to a set of three carbohydrate receptors of diverse origin, i.e. the human macrophage galactose-type lectin, a plant lectin, Pisum sativum agglutinin, and the bacterial Gal-/Glc-binding protein from Escherichia coli, it became possible to simultaneously define their monosaccharide selectivity and identify the essential hydroxyls for interaction.
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Affiliation(s)
- J. Daniel Martínez
- CIC
bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
| | - Ana I. Manzano
- Centro
de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Eva Calviño
- Centro
de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ana de Diego
- Centro
de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | | | - Cecilia Romanò
- Centre
for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Stefan Oscarson
- Centre
for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Oscar Millet
- CIC
bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
| | - Hans-Joachim Gabius
- Institute
of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
| | - Jesús Jiménez-Barbero
- CIC
bioGUNE, Basque Research Technology Alliance, BRTA, Bizkaia Technology Park, Building 800, 48160 Derio, Spain
- Ikerbasque,
Basque Foundation for Science, 48009 Bilbao, Spain
- Department
of Organic Chemistry II, Faculty of Science and Technology, UPV-EHU, 48940 Leioa, Spain
| | - Francisco J. Cañada
- Centro
de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
- Centro
de Investigación Biomédica en Red-Enfermedades Respiratorias
(CIBERES), Avda Monforte
de Lemos 3-5, 28029 Madrid, Spain
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9
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Kaczmarski JA, Mahawaththa MC, Feintuch A, Clifton BE, Adams LA, Goldfarb D, Otting G, Jackson CJ. Altered conformational sampling along an evolutionary trajectory changes the catalytic activity of an enzyme. Nat Commun 2020; 11:5945. [PMID: 33230119 PMCID: PMC7683729 DOI: 10.1038/s41467-020-19695-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023] Open
Abstract
Several enzymes are known to have evolved from non-catalytic proteins such as solute-binding proteins (SBPs). Although attention has been focused on how a binding site can evolve to become catalytic, an equally important question is: how do the structural dynamics of a binding protein change as it becomes an efficient enzyme? Here we performed a variety of experiments, including propargyl-DO3A-Gd(III) tagging and double electron-electron resonance (DEER) to study the rigid body protein dynamics of reconstructed evolutionary intermediates to determine how the conformational sampling of a protein changes along an evolutionary trajectory linking an arginine SBP to a cyclohexadienyl dehydratase (CDT). We observed that primitive dehydratases predominantly populate catalytically unproductive conformations that are vestiges of their ancestral SBP function. Non-productive conformational states, including a wide-open state, are frozen out of the conformational landscape via remote mutations, eventually leading to extant CDT that exclusively samples catalytically relevant compact states. These results show that remote mutations can reshape the global conformational landscape of an enzyme as a mechanism for increasing catalytic activity.
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Affiliation(s)
- Joe A Kaczmarski
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Mithun C Mahawaththa
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Akiva Feintuch
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Ben E Clifton
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia.,Protein Engineering and Evolution Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0412, Japan
| | - Luke A Adams
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Daniella Goldfarb
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Gottfried Otting
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia. .,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia.
| | - Colin J Jackson
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia. .,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia. .,Australian Research Council Centre of Excellence in Synthetic Biology, Research School of Chemistry, Australian National University, Canberra, 2601, ACT, Australia.
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10
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Rational design to control the trade-off between receptor affinity and cooperativity. Proc Natl Acad Sci U S A 2020; 117:19136-19140. [PMID: 32727893 DOI: 10.1073/pnas.2006254117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cooperativity enhances the responsiveness of biomolecular receptors to small changes in the concentration of their target ligand, albeit with a concomitant reduction in affinity. The binding midpoint of a two-site receptor with a Hill coefficient of 1.9, for example, must be at least 19 times higher than the dissociation constant of the higher affinity of its two binding sites. This trade-off can be overcome, however, by the extra binding energy provided by the addition of more binding sites, which can be used to achieve highly cooperative receptors that still retain high affinity. Exploring this experimentally, we have employed an "intrinsic disorder" mechanism to design two cooperative, three-binding-site receptors starting from a single-site-and thus noncooperative-doxorubicin-binding aptamer. The first receptor follows a binding energy landscape that partitions the energy provided by the additional binding event to favor affinity, achieving a Hill coefficient of 1.9 but affinity within a factor of 2 of the parent aptamer. The binding energy landscape of the second receptor, in contrast, partitions more of this energy toward cooperativity, achieving a Hill coefficient of 2.3, but at the cost of 4-fold poorer affinity than that of the parent aptamer. The switch between these two behaviors is driven primarily by the affinity of the receptors' second binding event, which serves as an allosteric "gatekeeper" defining the extent to which the system is weighted toward higher cooperativity or higher affinity.
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11
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Coarse-grained molecular dynamics simulation of protein conformational change coupled to ligand binding. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Kooshapur H, Ma J, Tjandra N, Bermejo GA. NMR Analysis of Apo Glutamine‐Binding Protein Exposes Challenges in the Study of Interdomain Dynamics. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
| | - Junhe Ma
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
- Present address: Ashland Specialty Ingredients 500 Hercules Rd. Wilmington DE 19808 USA
| | - Nico Tjandra
- Laboratory of Structural BiophysicsBiochemistry and Biophysics CenterNational Heart, Lung, and Blood InstituteNational Institutes of Health Bethesda MD 20892 USA
| | - Guillermo A. Bermejo
- Office of Intramural ResearchCenter for Information TechnologyNational Institutes of Health Bethesda MD 20892 USA
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13
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Kooshapur H, Ma J, Tjandra N, Bermejo GA. NMR Analysis of Apo Glutamine-Binding Protein Exposes Challenges in the Study of Interdomain Dynamics. Angew Chem Int Ed Engl 2019; 58:16899-16902. [PMID: 31515908 DOI: 10.1002/anie.201911015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Indexed: 02/06/2023]
Abstract
Glutamine-binding protein (GlnBP) displays an apo, "open" and a holo, "closed" crystal form, mutually related by a rigid-body reorientation of its domains. A fundamental question about such large-scale conformational transitions, whether the closed state exists in the absence of ligand, is controversial in the case of GlnBP. NMR observations have indicated no evidence of the closed form, whereas experimentally validated computations have suggested a remarkable ca. 40 % population. Herein, a paramagnetic NMR strategy designed to detect the putative apo-closed species shows that a major population of the latter is highly improbable. Further, NMR residual dipolar couplings collected under three anisotropic conditions do not reveal differential domain alignment and establish that the average solution conformation is satisfied by the apo-open crystal structure. Our results indicate that the computational prediction of large-scale interdomain motions is not trivial and may lead to erroneous conclusions without proper experimental validation.
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Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Junhe Ma
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.,Present address: Ashland Specialty Ingredients, 500 Hercules Rd., Wilmington, DE, 19808, USA
| | - Nico Tjandra
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Guillermo A Bermejo
- Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, MD, 20892, USA
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14
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Mussel-inspired antifouling magnetic activated carbon for uranium recovery from simulated seawater. J Colloid Interface Sci 2019; 534:172-182. [DOI: 10.1016/j.jcis.2018.09.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/01/2018] [Accepted: 09/07/2018] [Indexed: 01/05/2023]
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15
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Pluta P, Roversi P, Bernardo-Seisdedos G, Rojas AL, Cooper JB, Gu S, Pickersgill RW, Millet O. Structural basis of pyrrole polymerization in human porphobilinogen deaminase. Biochim Biophys Acta Gen Subj 2018; 1862:1948-1955. [PMID: 29908816 DOI: 10.1016/j.bbagen.2018.06.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/17/2018] [Accepted: 06/13/2018] [Indexed: 01/27/2023]
Abstract
Human porphobilinogen deaminase (PBGD), the third enzyme in the heme pathway, catalyzes four times a single reaction to convert porphobilinogen into hydroxymethylbilane. Remarkably, PBGD employs a single active site during the process, with a distinct yet chemically equivalent bond formed each time. The four intermediate complexes of the enzyme have been biochemically validated and they can be isolated but they have never been structurally characterized other than the apo- and holo-enzyme bound to the cofactor. We present crystal structures for two human PBGD intermediates: PBGD loaded with the cofactor and with the reaction intermediate containing two additional substrate pyrrole rings. These results, combined with SAXS and NMR experiments, allow us to propose a mechanism for the reaction progression that requires less structural rearrangements than previously suggested: the enzyme slides a flexible loop over the growing-product active site cavity. The structures and the mechanism proposed for this essential reaction explain how a set of missense mutations result in acute intermittent porphyria.
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Affiliation(s)
- Paula Pluta
- Protein Stability and Inherited Disease Laboratory, CIC bioGUNE, Derio, Bizkaia 48160, Spain
| | - Pietro Roversi
- Oxford Glycobiology Institute, Dept. of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7RH, England, UK
| | | | - Adriana L Rojas
- Structural Biology Unit, CIC bioGUNE, Derio, Bizkaia 48160, Spain
| | - Jonathan B Cooper
- Department of Biological Sciences, Birkbeck, London WC1E 7HX, UK; Division of Medicine, University College London, London WC1E 6BT, UK
| | - Shuang Gu
- School of Biological and Chemical Sciences, Chemistry & Biochemistry Department, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Richard W Pickersgill
- School of Biological and Chemical Sciences, Chemistry & Biochemistry Department, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Oscar Millet
- Protein Stability and Inherited Disease Laboratory, CIC bioGUNE, Derio, Bizkaia 48160, Spain.
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16
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Structural basis and energy landscape for the Ca 2+ gating and calmodulation of the Kv7.2 K + channel. Proc Natl Acad Sci U S A 2018; 115:2395-2400. [PMID: 29463698 PMCID: PMC5873240 DOI: 10.1073/pnas.1800235115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ion channels are sophisticated proteins that exert control over a plethora of body functions. Specifically, the members of the Kv7 family are prominent components of the nervous systems, responsible for the ion fluxes that regulate the electrical signaling in neurons and cardiac myocytes. Albeit its relevance, there are still several questions, including the Ca2+/calmodulin (CaM)-mediated gating mechanism. We found that Ca2+ binding to CaM triggers a segmental rotation that allosterically transmits the signal from the cytosol up to the transmembrane region. NMR-derived analysis of the dynamics demonstrates that it occurs through a conformational selection mechanism. Energetically, CaM association with the channel tunes the affinities of the CaM lobes (calmodulation) so that the channel can sense the specific changes in [Ca2+] resulting after an action potential. The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K+ M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca2+ gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of helices hA and hB of Kv7.2 with CaM, as a function of Ca2+ concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca2+ concentration (10–100 nM), only the N-lobe of CaM is Ca2+-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-populated excited state (1.5%) that corresponds to the inactive state of the channel. In response to a chemical or electrical signal, intracellular Ca2+ levels rise up to 1–10 μM, triggering Ca2+ association with the C-lobe. The associated conformational rearrangement is the key biological signal that shifts populations to the closed/inactive channel. This reorientation affects the C-lobe of CaM and both helices in Kv7.2, allosterically transducing the information from the Ca2+-binding site to the transmembrane region of the channel.
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17
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Abstract
Conditionally disordered proteins are either ordered or disordered depending on the environmental context. The substrates of the mitochondrial intermembrane space (IMS) oxidoreductase Mia40 are synthesized on cytosolic ribosomes and diffuse as intrinsically disordered proteins to the IMS, where they fold into their functional conformations; behaving thus as conditionally disordered proteins. It is not clear how the sequences of these polypeptides encode at the same time for their ability to adopt a folded structure and to remain unfolded. Here we characterize the disorder-to-order transition of a Mia40 substrate, the human small copper chaperone Cox17. Using an integrated real-time approach, including chromatography, fluorescence, CD, FTIR, SAXS, NMR, and MS analysis, we demonstrate that in this mitochondrial protein, the conformational switch between disordered and folded states is controlled by the formation of a single disulfide bond, both in the presence and in the absence of Mia40. We provide molecular details on how the folding of a conditionally disordered protein is tightly regulated in time and space, in such a way that the same sequence is competent for protein translocation and activity.
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18
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Fraga H, Pujols J, Gil-Garcia M, Roque A, Bernardo-Seisdedos G, Santambrogio C, Bech-Serra JJ, Canals F, Bernadó P, Grandori R, Millet O, Ventura S. Disulfide driven folding for a conditionally disordered protein. Sci Rep 2017; 7:16994. [PMID: 29208936 PMCID: PMC5717278 DOI: 10.1038/s41598-017-17259-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/23/2017] [Indexed: 11/09/2022] Open
Abstract
Conditionally disordered proteins are either ordered or disordered depending on the environmental context. The substrates of the mitochondrial intermembrane space (IMS) oxidoreductase Mia40 are synthesized on cytosolic ribosomes and diffuse as intrinsically disordered proteins to the IMS, where they fold into their functional conformations; behaving thus as conditionally disordered proteins. It is not clear how the sequences of these polypeptides encode at the same time for their ability to adopt a folded structure and to remain unfolded. Here we characterize the disorder-to-order transition of a Mia40 substrate, the human small copper chaperone Cox17. Using an integrated real-time approach, including chromatography, fluorescence, CD, FTIR, SAXS, NMR, and MS analysis, we demonstrate that in this mitochondrial protein, the conformational switch between disordered and folded states is controlled by the formation of a single disulfide bond, both in the presence and in the absence of Mia40. We provide molecular details on how the folding of a conditionally disordered protein is tightly regulated in time and space, in such a way that the same sequence is competent for protein translocation and activity.
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Affiliation(s)
- Hugo Fraga
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departamento de Bioquimica, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Jordi Pujols
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Marcos Gil-Garcia
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Alicia Roque
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | | | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | | | - Francesc Canals
- Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM-U1054, CNRS UMR-5048, Université de Montpellier, 29, rue de Navacelles, 34090, Montpellier, France
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | - Oscar Millet
- Protein Stability and Inherited Diseases Laboratory, CIC bioGUNE, 48160, Derio, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina. Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain. .,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
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19
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Fonin AV, Golikova AD, Zvereva IA, D'Auria S, Staiano M, Uversky VN, Kuznetsova IM, Turoverov KK. Osmolyte-Like Stabilizing Effects of Low GdnHCl Concentrations on d-Glucose/d-Galactose-Binding Protein. Int J Mol Sci 2017; 18:E2008. [PMID: 28925982 PMCID: PMC5618657 DOI: 10.3390/ijms18092008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/14/2017] [Accepted: 09/16/2017] [Indexed: 11/16/2022] Open
Abstract
The ability of d-glucose/d-galactose-binding protein (GGBP) to reversibly interact with its ligands, glucose and galactose, makes this protein an attractive candidate for sensing elements of glucose biosensors. This potential is largely responsible for attracting researchers to study the conformational properties of this protein. Previously, we showed that an increase in the fluorescence intensity of the fluorescent dye 6-bromoacetyl-2-dimetylaminonaphtalene (BADAN) is linked to the holo-form of the GGBP/H152C mutant in solutions containing sub-denaturing concentrations of guanidine hydrochloride (GdnHCl). It was hypothesized that low GdnHCl concentrations might lead to compaction of the protein, thereby facilitating ligand binding. In this work, we utilize BADAN fluorescence spectroscopy, intrinsic protein UV fluorescence spectroscopy, and isothermal titration calorimetry (ITC) to show that the sub-denaturing GdnHCl concentrations possess osmolyte-like stabilizing effects on the structural dynamics, conformational stability, and functional activity of GGBP/H152C and the wild type of this protein (wtGGBP). Our data are consistent with the model where low GdnHCl concentrations promote a shift in the dynamic distribution of the protein molecules toward a conformational ensemble enriched in molecules with a tighter structure and a more closed conformation. This promotes the increase in the configurational complementarity between the protein and glucose molecules that leads to the increase in glucose affinity in both GGBP/H152C and wtGGBP.
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Affiliation(s)
- Alexander V Fonin
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
| | - Alexandra D Golikova
- Saint Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia.
| | - Irina A Zvereva
- Saint Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia.
| | - Sabato D'Auria
- CNR, Institute of Food Science, via Roma 64, 83100 Avellino, Italy.
| | - Maria Staiano
- CNR, Institute of Food Science, via Roma 64, 83100 Avellino, Italy.
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., Tampa, FL 33612, USA.
| | - Irina M Kuznetsova
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
| | - Konstantin K Turoverov
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
- Department of Biophysics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya av. 29, 195251 St. Petersburg, Russia.
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20
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Kar RK, Kharerin H, Padinhateeri R, Bhat PJ. Multiple Conformations of Gal3 Protein Drive the Galactose-Induced Allosteric Activation of the GAL Genetic Switch of Saccharomyces cerevisiae. J Mol Biol 2016; 429:158-176. [PMID: 27913116 DOI: 10.1016/j.jmb.2016.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/04/2016] [Accepted: 11/04/2016] [Indexed: 01/01/2023]
Abstract
Gal3p is an allosteric monomeric protein that activates the GAL genetic switch of Saccharomyces cerevisiae in response to galactose. Expression of constitutive mutant of Gal3p or overexpression of wild-type Gal3p activates the GAL switch in the absence of galactose. These data suggest that Gal3p exists as an ensemble of active and inactive conformations. Structural data have indicated that Gal3p exists in open (inactive) and closed (active) conformations. However, a mutant of Gal3p that predominantly exists in inactive conformation and is yet capable of responding to galactose has not been isolated. To understand the mechanism of allosteric transition, we have isolated a triple mutant of Gal3p with V273I, T404A, and N450D substitutions, which, upon overexpression, fails to activate the GAL switch on its own but activates the switch in response to galactose. Overexpression of Gal3p mutants with single or double mutations in any of the three combinations failed to exhibit the behavior of the triple mutant. Molecular dynamics analysis of the wild-type and the triple mutant along with two previously reported constitutive mutants suggests that the wild-type Gal3p may also exist in super-open conformation. Furthermore, our results suggest that the dynamics of residue F237 situated in the hydrophobic pocket located in the hinge region drives the transition between different conformations. Based on this study, we suggest that conformational selection mechanism is the driving force in the allosteric transition of Gal3p, which may have implications in other signaling pathways involving monomeric proteins.
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Affiliation(s)
- Rajesh Kumar Kar
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India
| | - Hungyo Kharerin
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India
| | - Ranjith Padinhateeri
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India
| | - Paike Jayadeva Bhat
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India.
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21
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Unione L, Ortega G, Mallagaray A, Corzana F, Pérez-Castells J, Canales A, Jiménez-Barbero J, Millet O. Unraveling the Conformational Landscape of Ligand Binding to Glucose/Galactose-Binding Protein by Paramagnetic NMR and MD Simulations. ACS Chem Biol 2016; 11:2149-57. [PMID: 27219646 DOI: 10.1021/acschembio.6b00148] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein dynamics related to function can nowadays be structurally well characterized (i.e., instances obtained by high resolution structures), but they are still ill-defined energetically, and the energy landscapes are only accessible computationally. This is the case for glucose-galactose binding protein (GGBP), where the crystal structures of the apo and holo states provide structural information for the domain rearrangement upon ligand binding, while the time scale and the energetic determinants for such concerted dynamics have been so far elusive. Here, we use GGBP as a paradigm to define a functional conformational landscape, both structurally and energetically, by using an innovative combination of paramagnetic NMR experiments and MD simulations. Anisotropic NMR parameters induced by self-alignment of paramagnetic metal ions was used to characterize the ensemble of conformations adopted by the protein in solution while the rate of interconversion between conformations was elucidated by long molecular dynamics simulation on two states of GGBP, the closed-liganded (holo_cl) and open-unloaded (apo_op) states. Our results demonstrate that, in its apo state, the protein coexists between open-like (68%) and closed-like (32%) conformations, with an exchange rate around 25 ns. Despite such conformational heterogeneity, the presence of the ligand is the ultimate driving force to unbalance the equilibrium toward the holo_cl form, in a mechanism largely governed by a conformational selection mechanism.
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Affiliation(s)
- Luca Unione
- Molecular
Recognition and Host−Pathogen Interactions, CICbioGUNE, Bizkaia
Technology Park, Building 801 A, 48170 Derio, Spain
| | - Gabriel Ortega
- Molecular
Recognition and Host−Pathogen Interactions, CICbioGUNE, Bizkaia
Technology Park, Building 801 A, 48170 Derio, Spain
| | - Alvaro Mallagaray
- Institute
of Chemistry, Center for Structural and Cell Biology in Medicine (CSCM), University of Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany
| | - Francisco Corzana
- Departamento
de Química y Centro de Investigación en Síntesis
Química, Universidad de La Rioja, 26006 Logroño, La Rioja, Spain
| | - Javier Pérez-Castells
- Facultad
de Farmacia, Dpto. Química y Bioquímica, Universidad San Pablo CEU, Urb. Montepríncipe, ctra., Boadilla km 5,300
Boadilla del Monte, 28668 Madrid, Spain
| | - Angeles Canales
- Department
of Química Orgánica I, Fac. C. C. Químicas, Universidad Complutense de Madrid, Avd. Complutense s/n, 28040 Madrid, Spain
| | - Jesús Jiménez-Barbero
- Molecular
Recognition and Host−Pathogen Interactions, CICbioGUNE, Bizkaia
Technology Park, Building 801 A, 48170 Derio, Spain
- Ikerbasque, Basque
Foundation
for Science, Maria Diaz de Haro 13, 48009 Bilbao, Spain
- Departament of Organic Chemistry II, Faculty of Science & Technology, University of the Basque Country, 48940 Leioa, Bizkaia Spain
| | - Oscar Millet
- Molecular
Recognition and Host−Pathogen Interactions, CICbioGUNE, Bizkaia
Technology Park, Building 801 A, 48170 Derio, Spain
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22
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Cai Z, Luck LA, Punihaole D, Madura JD, Asher SA. Photonic crystal protein hydrogel sensor materials enabled by conformationally induced volume phase transition. Chem Sci 2016; 7:4557-4562. [PMID: 30155102 PMCID: PMC6016329 DOI: 10.1039/c6sc00682e] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 03/23/2016] [Indexed: 01/09/2023] Open
Abstract
Hydrogels that change volume in response to specific molecular stimuli can serve as platforms for sensors, actuators and drug delivery devices. There is great interest in designing intelligent hydrogels for tissue engineering, drug delivery, and microfluidics that utilize protein binding specificities and conformational changes. Protein conformational change induced by ligand binding can cause volume phase transitions (VPTs). Here, we develop a highly selective glucose sensing protein photonic crystal (PC) hydrogel that is fabricated from genetically engineered E. coli glucose/galactose binding protein (GGBP). The resulting 2-D PC-GGBP hydrogel undergoes a VPT in response to glucose. The volume change causes the 2-D PC array particle spacing to decrease, leading to a blue-shifted diffraction which enables our sensors to report on glucose concentrations. This 2-D PC-GGBP responsive hydrogel functions as a selective and sensitive sensor that easily monitors glucose concentrations from ∼0.2 μM to ∼10 mM. This work demonstrates a proof-of-concept for developing responsive, "smart" protein hydrogel materials with VPTs that utilize ligand binding induced protein conformational changes. This innovation may enable the development of other novel chemical sensors and high-throughput screening devices that can monitor protein-drug binding interactions.
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Affiliation(s)
- Zhongyu Cai
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , USA .
| | - Linda A Luck
- Department of Chemistry , State University of New York at Plattsburgh , Plattsburgh , NY 12901 , USA
| | - David Punihaole
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , USA .
| | - Jeffry D Madura
- Department of Chemistry and Biochemistry , Duquesne University , Pittsburgh , Pennsylvania 15282 , USA
| | - Sanford A Asher
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , USA .
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23
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Antonik PM, Volkov AN, Broder UN, Re DL, van Nuland NAJ, Crowley PB. Anomer-Specific Recognition and Dynamics in a Fucose-Binding Lectin. Biochemistry 2016; 55:1195-203. [PMID: 26845253 DOI: 10.1021/acs.biochem.5b01212] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Sugar binding by a cell surface ∼29 kDa lectin (RSL) from the bacterium Ralstonia solanacearum was characterized by NMR spectroscopy. The complexes formed with four monosaccharides and four fucosides were studied. Complete resonance assignments and backbone dynamics were determined for RSL in the sugar-free form and when bound to l-fucose or d-mannose. RSL was found to interact with both the α- and the β-anomer of l-fucose and the "fucose like" sugars d-arabinose and l-galactose. Peak splitting was observed for some resonances of the binding site residues. The assignment of the split signals to the α- or β-anomer was confirmed by comparison with the spectra of RSL bound to methyl-α-l-fucoside or methyl-β-l-fucoside. The backbone dynamics of RSL were sensitive to the presence of ligand, with the protein adopting a more compact structure upon binding to l-fucose. Taking advantage of tryptophan residues in the binding sites, we show that the indole resonance is an excellent reporter on ligand binding. Each sugar resulted in a distinct signature of chemical shift perturbations, suggesting that tryptophan signals are a sufficient probe of sugar binding.
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Affiliation(s)
- Paweł M Antonik
- School of Chemistry, National University of Ireland Galway , University Road, Galway, Ireland.,Department of Food BioSciences, Teagasc Food Research Centre , Ashtown, Dublin 15, Ireland
| | - Alexander N Volkov
- Jean Jeener NMR Centre, Structural Biology Brussels, Vrije Universiteit Brussel , Pleinlaan 2, 1050 Brussels, Belgium.,Structural Biology Research Centre, VIB, Pleinlaan 2, 1050 Brussels, Belgium
| | - Ursula N Broder
- School of Chemistry, National University of Ireland Galway , University Road, Galway, Ireland
| | - Daniele Lo Re
- School of Chemistry, National University of Ireland Galway , University Road, Galway, Ireland
| | - Nico A J van Nuland
- Jean Jeener NMR Centre, Structural Biology Brussels, Vrije Universiteit Brussel , Pleinlaan 2, 1050 Brussels, Belgium.,Structural Biology Research Centre, VIB, Pleinlaan 2, 1050 Brussels, Belgium
| | - Peter B Crowley
- School of Chemistry, National University of Ireland Galway , University Road, Galway, Ireland
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24
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Abdelkader EH, Yao X, Feintuch A, Adams LA, Aurelio L, Graham B, Goldfarb D, Otting G. Pulse EPR-enabled interpretation of scarce pseudocontact shifts induced by lanthanide binding tags. JOURNAL OF BIOMOLECULAR NMR 2016; 64:39-51. [PMID: 26597990 DOI: 10.1007/s10858-015-0003-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
Pseudocontact shifts (PCS) induced by tags loaded with paramagnetic lanthanide ions provide powerful long-range structure information, provided the location of the metal ion relative to the target protein is known. Usually, the metal position is determined by fitting the magnetic susceptibility anisotropy (Δχ) tensor to the 3D structure of the protein in an 8-parameter fit, which requires a large set of PCSs to be reliable. In an alternative approach, we used multiple Gd(3+)-Gd(3+) distances measured by double electron-electron resonance (DEER) experiments to define the metal position, allowing Δχ-tensor determinations from more robust 5-parameter fits that can be performed with a relatively sparse set of PCSs. Using this approach with the 32 kDa E. coli aspartate/glutamate binding protein (DEBP), we demonstrate a structural transition between substrate-bound and substrate-free DEBP, supported by PCSs generated by C3-Tm(3+) and C3-Tb(3+) tags attached to a genetically encoded p-azidophenylalanine residue. The significance of small PCSs was magnified by considering the difference between the chemical shifts measured with Tb(3+) and Tm(3+) rather than involving a diamagnetic reference. The integrative sparse data approach developed in this work makes poorly soluble proteins of limited stability amenable to structural studies in solution, without having to rely on cysteine mutations for tag attachment.
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Affiliation(s)
- Elwy H Abdelkader
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Xuejun Yao
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Akiva Feintuch
- Department of Chemical Physics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Luke A Adams
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Daniella Goldfarb
- Department of Chemical Physics, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Gottfried Otting
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia.
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25
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Pulido NO, Silva DA, Tellez LA, Pérez-Hernández G, García-Hernández E, Sosa-Peinado A, Fernández-Velasco DA. On the molecular basis of the high affinity binding of basic amino acids to LAOBP, a periplasmic binding protein fromSalmonella typhimurium. J Mol Recognit 2015; 28:108-16. [DOI: 10.1002/jmr.2434] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/20/2014] [Accepted: 09/15/2014] [Indexed: 12/21/2022]
Affiliation(s)
- Nancy O. Pulido
- Laboratorio de Fisicoquímica e Ingeniería de Proteínas, Departamento de Bioquímica, Facultad de Medicina; Universidad Nacional Autónoma de México; México DF Mexico
| | - Daniel-Adriano Silva
- Laboratorio de Fisicoquímica e Ingeniería de Proteínas, Departamento de Bioquímica, Facultad de Medicina; Universidad Nacional Autónoma de México; México DF Mexico
- Biochemistry Department; University of Washington; Seattle WA USA
| | - Luis A. Tellez
- Laboratorio de Fisicoquímica e Ingeniería de Proteínas, Departamento de Bioquímica, Facultad de Medicina; Universidad Nacional Autónoma de México; México DF Mexico
- Department of Psychiatry; Yale University School of Medicine; New Haven CT USA
| | - Gerardo Pérez-Hernández
- Departamento de Ciencias Naturales; Universidad Autónoma Metropolitana- Cuajimalpa; México DF Mexico
| | - Enrique García-Hernández
- Instituto de Química; Universidad Nacional Autónoma de México; Circuito Exterior, Ciudad Universitaria México 04510 DF Mexico
| | - Alejandro Sosa-Peinado
- Laboratorio de Fisicoquímica e Ingeniería de Proteínas, Departamento de Bioquímica, Facultad de Medicina; Universidad Nacional Autónoma de México; México DF Mexico
| | - D. Alejandro Fernández-Velasco
- Laboratorio de Fisicoquímica e Ingeniería de Proteínas, Departamento de Bioquímica, Facultad de Medicina; Universidad Nacional Autónoma de México; México DF Mexico
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26
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Situ SF, Samia ACS. Highly efficient antibacterial iron oxide@carbon nanochains from wüstite precursor nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2014; 6:20154-20163. [PMID: 25347201 DOI: 10.1021/am505744m] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A new hydrothermal synthesis approach involving the carbonization of glucose in the presence of wüstite (FeO) nanoparticles is presented, which leads to the fabrication of rapidly acting and potent antibacterial agents based on iron oxide@carbon (IO@C) nanochains. By using nonmagnetic FeO precursor nanoparticles that slowly oxidize into the magnetic Fe3O4 crystal structure under hydrothermal conditions, we were able to prepare well-defined and short-length IO@C nanochains that are highly dispersed in aqueous media and readily interact with bacterial cells, leading to a complete loss in bacterial cell viability within short incubation times at minimal dosage. The smaller IO@C nanochains synthesized using the FeO precursor nanoparticles can reach above 2-fold enhancement in microbe-killing activity when compared to the larger nanochains fabricated directly from Fe3O4 nanoparticles. In addition, the synthesized IO@C nanochains can be easily isolated using an external magnet and be subsequently recycled to effectively eradicate Escherichia coli cells even after five separate treatment cycles.
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Affiliation(s)
- Shu F Situ
- Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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27
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Gu S, Silva DA, Meng L, Yue A, Huang X. Quantitatively characterizing the ligand binding mechanisms of choline binding protein using Markov state model analysis. PLoS Comput Biol 2014; 10:e1003767. [PMID: 25101697 PMCID: PMC4125059 DOI: 10.1371/journal.pcbi.1003767] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 06/22/2014] [Indexed: 01/05/2023] Open
Abstract
Protein-ligand recognition plays key roles in many biological processes. One of the most fascinating questions about protein-ligand recognition is to understand its underlying mechanism, which often results from a combination of induced fit and conformational selection. In this study, we have developed a three-pronged approach of Markov State Models, Molecular Dynamics simulations, and flux analysis to determine the contribution of each model. Using this approach, we have quantified the recognition mechanism of the choline binding protein (ChoX) to be ∼90% conformational selection dominant under experimental conditions. This is achieved by recovering all the necessary parameters for the flux analysis in combination with available experimental data. Our results also suggest that ChoX has several metastable conformational states, of which an apo-closed state is dominant, consistent with previous experimental findings. Our methodology holds great potential to be widely applied to understand recognition mechanisms underlining many fundamental biological processes.
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Affiliation(s)
- Shuo Gu
- Department of Chemistry, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Daniel-Adriano Silva
- Department of Chemistry, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Luming Meng
- Department of Chemistry, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Alexander Yue
- Department of Chemistry, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Xuhui Huang
- Department of Chemistry, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Division of Biomedical Engineering, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Center of Systems Biology and Human Health, Institute for Advance Study and School of Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- * E-mail:
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28
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ben Bdira F, González E, Pluta P, Laín A, Sanz-Parra A, Falcon-Perez JM, Millet O. Tuning intracellular homeostasis of human uroporphyrinogen III synthase by enzyme engineering at a single hotspot of congenital erythropoietic porphyria. Hum Mol Genet 2014; 23:5805-13. [PMID: 24925316 DOI: 10.1093/hmg/ddu298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Congenital erythropoietic porphyria (CEP) results from a deficiency in uroporphyrinogen III synthase enzyme (UROIIIS) activity that ultimately stems from deleterious mutations in the uroS gene. C73 is a hotspot for these mutations and a C73R substitution, which drastically reduces the enzyme activity and stability, is found in almost one-third of all reported CEP cases. Here, we have studied the structural basis, by which mutations in this hotspot lead to UROIIIS destabilization. First, a strong interdependency is observed between the volume of the side chain at position 73 and the folded protein. Moreover, there is a correlation between the in vitro half-life of the mutated proteins and their expression levels in eukaryotic cell lines. Molecular modelling was used to rationalize the results, showing that the mutation site is coupled to the hinge region separating the two domains. Namely, mutations at position 73 modulate the inter-domain closure and ultimately affect protein stability. By incorporating residues capable of interacting with R73 to stabilize the hinge region, catalytic activity was fully restored and a moderate increase in the kinetic stability of the enzyme was observed. These results provide an unprecedented rationale for a destabilizing missense mutation and pave the way for the effective design of molecular chaperones as a therapy against CEP.
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Affiliation(s)
- Fredj ben Bdira
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
| | - Esperanza González
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
| | - Paula Pluta
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
| | - Ana Laín
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
| | - Arantza Sanz-Parra
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
| | - Juan Manuel Falcon-Perez
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain
| | - Oscar Millet
- Structural Biology Unit and Metabolomics Unit, CIC bioGUNE, Bizkaia Technology Park, Building 800-801A, Derio 48160, Spain and
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29
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Affiliation(s)
- Alan C. Gibbs
- Janssen Pharmaceutical Research and Development, LLC, Welsh and McKean Road, Spring House, Pennsylvania 19477-0776, United States
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30
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Maity A, Majumdar S, Priya P, De P, Saha S, Ghosh Dastidar S. Adaptability in protein structures: structural dynamics and implications in ligand design. J Biomol Struct Dyn 2014; 33:298-321. [PMID: 24433438 DOI: 10.1080/07391102.2013.873002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The basic framework of understanding the mechanisms of protein functions is achieved from the knowledge of their structures which can model the molecular recognition. Recent advancement in the structural biology has revealed that in spite of the availability of the structural data, it is nontrivial to predict the mechanism of the molecular recognition which progresses via situation-dependent structural adaptation. The mutual selectivity of protein-protein and protein-ligand interactions often depends on the modulations of conformations empowered by their inherent flexibility, which in turn regulates the function. The mechanism of a protein's function, which used to be explained by the ideas of 'lock and key' has evolved today as the concept of 'induced fit' as well as the 'population shift' models. It is felt that the 'dynamics' is an essential feature to take into account for understanding the mechanism of protein's function. The design principles of therapeutic molecules suffer from the problems of plasticity of the receptors whose binding conformations are accurately not predictable from the prior knowledge of a template structure. On the other hand, flexibility of the receptors provides the opportunity to improve the binding affinity of a ligand by suitable substitution that will maximize the binding by modulating the receptors surface. In this paper, we discuss with example how the protein's flexibility is correlated with its functions in various systems, revealing the importance of its understanding and for making applications. We also highlight the methodological challenges to investigate it computationally and to account for the flexible nature of the molecules in drug design.
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Affiliation(s)
- Atanu Maity
- a Bioinformatics Centre, Bose Institute , P-1/12, C.I.T. Scheme VII M, Kolkata 700054 , India
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31
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Unione L, Galante S, Díaz D, Cañada FJ, Jiménez-Barbero J. NMR and molecular recognition. The application of ligand-based NMR methods to monitor molecular interactions. MEDCHEMCOMM 2014. [DOI: 10.1039/c4md00138a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
NMR allows the monitoring of molecular recognition processes in solution. Nowadays, a plethora of NMR methods are available to deduce the key features of the interaction from both the ligand or the receptor points of view.
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Affiliation(s)
- Luca Unione
- Chemical and Physical Biology
- Centro de Investigaciones Biológicas
- CSIC
- 28040 Madrid, Spain
| | - Silvia Galante
- Chemical and Physical Biology
- Centro de Investigaciones Biológicas
- CSIC
- 28040 Madrid, Spain
| | - Dolores Díaz
- Chemical and Physical Biology
- Centro de Investigaciones Biológicas
- CSIC
- 28040 Madrid, Spain
| | - F. Javier Cañada
- Chemical and Physical Biology
- Centro de Investigaciones Biológicas
- CSIC
- 28040 Madrid, Spain
| | - Jesús Jiménez-Barbero
- Chemical and Physical Biology
- Centro de Investigaciones Biológicas
- CSIC
- 28040 Madrid, Spain
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32
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Chu BCH, Chan DI, DeWolf T, Periole X, Vogel HJ. Molecular dynamics simulations reveal that apo-HisJ can sample a closed conformation. Proteins 2013; 82:386-98. [DOI: 10.1002/prot.24396] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/12/2013] [Accepted: 08/14/2013] [Indexed: 11/11/2022]
Affiliation(s)
- B. C. H. Chu
- Department of Biological Sciences; University of Calgary; Calgary Alberta T2N 1N4 Canada
| | - D. I. Chan
- Department of Biological Sciences; University of Calgary; Calgary Alberta T2N 1N4 Canada
| | - T. DeWolf
- Department of Biological Sciences; University of Calgary; Calgary Alberta T2N 1N4 Canada
| | - X. Periole
- Groningen Biomolecular Sciences and Biotechnology Institute, Zernike Institute for Advanced Materials; University of Groningen; Nijenborgh 7, 9747 AG Groningen The Netherlands
| | - H. J. Vogel
- Department of Biological Sciences; University of Calgary; Calgary Alberta T2N 1N4 Canada
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Chu BCH, DeWolf T, Vogel HJ. Role of the two structural domains from the periplasmic Escherichia coli histidine-binding protein HisJ. J Biol Chem 2013; 288:31409-22. [PMID: 24036119 DOI: 10.1074/jbc.m113.490441] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Escherichia coli HisJ is a type II periplasmic binding protein that functions to reversibly capture histidine and transfer it to its cognate inner membrane ABC permease. Here, we used NMR spectroscopy to determine the structure of apo-HisJ (26.5 kDa) in solution. HisJ is a bilobal protein in which domain 1 (D1) is made up of two noncontiguous subdomains, and domain 2 (D2) is expressed as the inner domain. To better understand the roles of D1 and D2, we have isolated and characterized each domain separately. Structurally, D1 closely resembles its homologous domain in apo- and holo-HisJ, whereas D2 is more similar to the holo-form. NMR relaxation experiments reveal that HisJ becomes more ordered upon ligand binding, whereas isolated D2 experiences a significant reduction in slower (millisecond to microsecond) motions compared with the homologous domain in apo-HisJ. NMR titrations reveal that D1 is able to bind histidine in a similar manner as full-length HisJ, albeit with lower affinity. Unexpectedly, isolated D1 and D2 do not interact with each other in the presence or absence of histidine, which indicates the importance of intact interdomain-connecting elements (i.e. hinge regions) for HisJ functioning. Our results shed light on the binding mechanism of type II periplasmic binding proteins where ligand is initially bound by D1, and D2 plays a supporting role in this dynamic process.
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Affiliation(s)
- Byron C H Chu
- From the Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Alberta T2N 1N4, Canada
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34
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NMR spectroscopy on domain dynamics in biomacromolecules. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 112:58-117. [DOI: 10.1016/j.pbiomolbio.2013.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 12/22/2022]
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