1
|
Li XD, Tan ZZ, Wu D, Zhao X, Dong LL, Zhan ML, Huang LY, Zhou M, Zhao KH. Structure Reveals the Impact of Surface Charge Distribution on the Phase Separation and Aggregation of Slr0280. Biochemistry 2023. [PMID: 37319348 DOI: 10.1021/acs.biochem.3c00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Liquid-liquid phase separation (LLPS) plays a key role in the regulation of life activities. Here, we reported a protein from Synechocystis sp. PCC 6803 and annotated as Slr0280. To obtain a water-soluble protein, we deleted the N-terminus transmembrane domain and named it Slr0280Δ. Slr0280Δ with high concentration can undergo LLPS at a low temperature in vitro. It belongs to the phosphodiester glycosidase family of proteins and has a segment of a low-complexity sequence region (LCR), which is thought to regulate the LLPS. Our results show that electrostatic interactions impact the LLPS of Slr0280Δ. We also acquired the structure of Slr0280Δ, which has many grooves on the surface with a large distribution of positive and negative charges. This may be advantageous for the LLPS of Slr0280Δ through electrostatic interactions. Furthermore, the conserved amino acid (arginine at position 531) located on the LCR is important for maintaining the stability of Slr0280Δ as well as LLPS. Our research indicated that the LLPS of proteins can be transformed into aggregation by changing the surface charge distribution.
Collapse
Affiliation(s)
- Xiao-Dan Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Zi-Zhu Tan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Dong Wu
- Computer Aided Drug Discovery Center, Zhuhai Institute of Advanced Technology, Chinese Academy of Sciences, Zhuhai 519003, P. R. China
| | - Xi Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Liang-Liang Dong
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Min-Li Zhan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Li-Yan Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Ming Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Kai-Hong Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| |
Collapse
|
2
|
Singer JM, Novotney S, Strickland D, Haddox HK, Leiby N, Rocklin GJ, Chow CM, Roy A, Bera AK, Motta FC, Cao L, Strauch EM, Chidyausiku TM, Ford A, Ho E, Zaitzeff A, Mackenzie CO, Eramian H, DiMaio F, Grigoryan G, Vaughn M, Stewart LJ, Baker D, Klavins E. Large-scale design and refinement of stable proteins using sequence-only models. PLoS One 2022; 17:e0265020. [PMID: 35286324 PMCID: PMC8920274 DOI: 10.1371/journal.pone.0265020] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/18/2022] [Indexed: 12/25/2022] Open
Abstract
Engineered proteins generally must possess a stable structure in order to achieve their designed function. Stable designs, however, are astronomically rare within the space of all possible amino acid sequences. As a consequence, many designs must be tested computationally and experimentally in order to find stable ones, which is expensive in terms of time and resources. Here we use a high-throughput, low-fidelity assay to experimentally evaluate the stability of approximately 200,000 novel proteins. These include a wide range of sequence perturbations, providing a baseline for future work in the field. We build a neural network model that predicts protein stability given only sequences of amino acids, and compare its performance to the assayed values. We also report another network model that is able to generate the amino acid sequences of novel stable proteins given requested secondary sequences. Finally, we show that the predictive model-despite weaknesses including a noisy data set-can be used to substantially increase the stability of both expert-designed and model-generated proteins.
Collapse
Affiliation(s)
| | - Scott Novotney
- Two Six Technologies, Arlington, Virginia, United States of America
| | - Devin Strickland
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington, United States of America
| | - Hugh K. Haddox
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Nicholas Leiby
- Two Six Technologies, Arlington, Virginia, United States of America
| | - Gabriel J. Rocklin
- Department of Pharmacology and Center for Synthetic Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Cameron M. Chow
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Anindya Roy
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Asim K. Bera
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Francis C. Motta
- Department of Mathematical Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Longxing Cao
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Eva-Maria Strauch
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia, United States of America
| | - Tamuka M. Chidyausiku
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Alex Ford
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Ethan Ho
- Texas Advanced Computing Center, Austin, Texas, United States of America
| | | | - Craig O. Mackenzie
- Quantitative Biomedical Sciences Graduate Program, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Hamed Eramian
- Netrias, Cambridge, Massachusetts, United States of America
| | - Frank DiMaio
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Gevorg Grigoryan
- Departments of Computer Science and Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Matthew Vaughn
- Texas Advanced Computing Center, Austin, Texas, United States of America
| | - Lance J. Stewart
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - David Baker
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Eric Klavins
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
3
|
de Godoi Contessoto V, Ramos FC, de Melo RR, de Oliveira VM, Scarpassa JA, de Sousa AS, Zanphorlin LM, Slade GG, Leite VBP, Ruller R. Electrostatic interaction optimization improves catalytic rates and thermotolerance on xylanases. Biophys J 2021; 120:2172-2180. [PMID: 33831390 DOI: 10.1016/j.bpj.2021.03.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/08/2021] [Accepted: 03/23/2021] [Indexed: 10/21/2022] Open
Abstract
Understanding the aspects that contribute to improving proteins' biochemical properties is of high relevance for protein engineering. Properties such as the catalytic rate, thermal stability, and thermal resistance are crucial for applying enzymes in the industry. Different interactions can influence those biochemical properties of an enzyme. Among them, the surface charge-charge interactions have been a target of particular attention. In this study, we employ the Tanford-Kirkwood solvent accessibility model using the Monte Carlo algorithm (TKSA-MC) to predict possible interactions that could improve stability and catalytic rate of a WT xylanase (XynAWT) and its M6 xylanase (XynAM6) mutant. The modeling prediction indicates that mutating from a lysine in position 99 to a glutamic acid (K99E) favors the native state stabilization in both xylanases. Our lab results showed that mutated xylanases had their thermotolerance and catalytic rate increased, which conferred higher processivity of delignified sugarcane bagasse. The TKSA-MC approach employed here is presented as an efficient computational-based design strategy that can be applied to improve the thermal resistance of enzymes with industrial and biotechnological applications.
Collapse
Affiliation(s)
- Vinícius de Godoi Contessoto
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil; Center for Theoretical Biological Physics, Rice University, Houston, Texas; Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University, São José do Rio Preto, São Paulo, Brazil
| | - Felipe Cardoso Ramos
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Ricardo Rodrigues de Melo
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Vinícius Martins de Oliveira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Josiane Aniele Scarpassa
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Amanda Silva de Sousa
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Letıcia Maria Zanphorlin
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo, Brazil
| | - Gabriel Gouvea Slade
- Theoretical Biophysics Laboratory, Institute of Exact Sciences, Natural and Education, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Vitor Barbanti Pereira Leite
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University, São José do Rio Preto, São Paulo, Brazil.
| | - Roberto Ruller
- Microorganisms and General Biochemistry Laboratory, Institute of Bioscience, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| |
Collapse
|
4
|
Se Thoe E, Fauzi A, Tang YQ, Chamyuang S, Chia AYY. A review on advances of treatment modalities for Alzheimer's disease. Life Sci 2021; 276:119129. [PMID: 33515559 DOI: 10.1016/j.lfs.2021.119129] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/10/2021] [Accepted: 01/19/2021] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial neurodegenerative disease which is mainly characterized by progressive impairment in cognition, emotion, language and memory in older population. Considering the impact of AD, formulations of pharmaceutical drugs and cholinesterase inhibitors have been widely propagated, receiving endorsement by FDA as a form of AD treatment. However, these medications were gradually discovered to be ineffective in removing the root of AD pathogenesis but merely targeting the symptoms so as to improve a patient's cognitive outcome. Hence, a search for better disease-modifying alternatives is put into motion. Having a clear understanding of the neuroprotective mechanisms and diverse properties undertaken by specific genes, antibodies and nanoparticles is central towards designing novel therapeutic agents. In this review, we provide a brief introduction on the background of Alzheimer's disease, the biology of blood-brain barrier, along with the potentials and drawbacks associated with current therapeutic treatment avenues pertaining to gene therapy, immunotherapy and nanotherapy for better diagnosis and management of Alzheimer's disease.
Collapse
Affiliation(s)
- Ewen Se Thoe
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor's University, 47500 Selangor, Malaysia
| | - Ayesha Fauzi
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor's University, 47500 Selangor, Malaysia
| | - Yin Quan Tang
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor's University, 47500 Selangor, Malaysia
| | - Sunita Chamyuang
- School of Science, Mae Fah Luang University, Chaing Rai 57100, Thailand; Microbial Products and Innovation Research Group, Mae Fah Luang University, Chaing Rai 57100, Thailand
| | - Adeline Yoke Yin Chia
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor's University, 47500 Selangor, Malaysia.
| |
Collapse
|
5
|
Heinemann U, Roske Y. Cold-Shock Domains-Abundance, Structure, Properties, and Nucleic-Acid Binding. Cancers (Basel) 2021; 13:cancers13020190. [PMID: 33430354 PMCID: PMC7825780 DOI: 10.3390/cancers13020190] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Proteins are composed of compact domains, often of known three-dimensional structure, and natively unstructured polypeptide regions. The abundant cold-shock domain is among the set of canonical nucleic acid-binding domains and conserved from bacteria to man. Proteins containing cold-shock domains serve a large variety of biological functions, which are mostly linked to DNA or RNA binding. These functions include the regulation of transcription, RNA splicing, translation, stability and sequestration. Cold-shock domains have a simple architecture with a conserved surface ideally suited to bind single-stranded nucleic acids. Because the binding is mostly by non-specific molecular interactions which do not involve the sugar-phosphate backbone, cold-shock domains are not strictly sequence-specific and do not discriminate reliably between DNA and RNA. Many, but not all functions of cold shock-domain proteins in health and disease can be understood based of the physical and structural properties of their cold-shock domains. Abstract The cold-shock domain has a deceptively simple architecture but supports a complex biology. It is conserved from bacteria to man and has representatives in all kingdoms of life. Bacterial cold-shock proteins consist of a single cold-shock domain and some, but not all are induced by cold shock. Cold-shock domains in human proteins are often associated with natively unfolded protein segments and more rarely with other folded domains. Cold-shock proteins and domains share a five-stranded all-antiparallel β-barrel structure and a conserved surface that binds single-stranded nucleic acids, predominantly by stacking interactions between nucleobases and aromatic protein sidechains. This conserved binding mode explains the cold-shock domains’ ability to associate with both DNA and RNA strands and their limited sequence selectivity. The promiscuous DNA and RNA binding provides a rationale for the ability of cold-shock domain-containing proteins to function in transcription regulation and DNA-damage repair as well as in regulating splicing, translation, mRNA stability and RNA sequestration.
Collapse
|
6
|
Ferreira PHB, Freitas FC, McCully ME, Slade GG, de Oliveira RJ. The Role of Electrostatics and Folding Kinetics on the Thermostability of Homologous Cold Shock Proteins. J Chem Inf Model 2020; 60:546-561. [PMID: 31910002 DOI: 10.1021/acs.jcim.9b00797] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Understanding which aspects contribute to the thermostability of proteins is a challenge that has persisted for decades, and it is of great relevance for protein engineering. Several types of interactions can influence the thermostability of a protein. Among them, the electrostatic interactions have been a target of particular attention. Aiming to explore how this type of interaction can affect protein thermostability, this paper investigated four homologous cold shock proteins from psychrophilic, mesophilic, thermophilic, and hyperthermophilic organisms using a set of theoretical methodologies. It is well-known that electrostatics as well as hydrophobicity are key-elements for the stabilization of these proteins. Therefore, both interactions were initially analyzed in the native structure of each protein. Electrostatic interactions present in the native structures were calculated with the Tanford-Kirkwood model with solvent accessibility, and the amount of hydrophobic surface area buried upon folding was estimated by measuring both folded and extended structures. On the basis of Energy Landscape Theory, the local frustration and the simplified alpha-carbon structure-based model were modeled with a Debye-Hückel potential to take into account the electrostatics and the effects of an implicit solvent. Thermodynamic data for the structure-based model simulations were collected and analyzed using the Weighted Histogram Analysis and Stochastic Diffusion methods. Kinetic quantities including folding times, transition path times, folding routes, and Φ values were also obtained. As a result, we found that the methods are able to qualitatively infer that electrostatic interactions play an important role on the stabilization of the most stable thermophilic cold shock proteins, showing agreement with the experimental data.
Collapse
Affiliation(s)
- Paulo Henrique Borges Ferreira
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação , Universidade Federal do Triângulo Mineiro , Uberaba , Minas Gerais 38064200 , Brazil
| | - Frederico Campos Freitas
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação , Universidade Federal do Triângulo Mineiro , Uberaba , Minas Gerais 38064200 , Brazil
| | - Michelle E McCully
- Department of Biology , Santa Clara University , Santa Clara , California 95050 , United States
| | - Gabriel Gouvêa Slade
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação , Universidade Federal do Triângulo Mineiro , Uberaba , Minas Gerais 38064200 , Brazil
| | - Ronaldo Junio de Oliveira
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação , Universidade Federal do Triângulo Mineiro , Uberaba , Minas Gerais 38064200 , Brazil
| |
Collapse
|
7
|
Contessoto VG, de Oliveira VM, Fernandes BR, Slade GG, Leite VBP. TKSA-MC: A web server for rational mutation through the optimization of protein charge interactions. Proteins 2018; 86:1184-1188. [PMID: 30218467 DOI: 10.1002/prot.25599] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/24/2018] [Accepted: 08/31/2018] [Indexed: 11/06/2022]
Abstract
The TKSAMC is a web server which calculates protein charge-charge interactions via the Tanford-Kirkwood Surface Accessibility model with the Monte Carlo method for sampling different protein protonation states. The optimization of charge-charge interactions via directed mutations has successfully enhanced the thermal stability of different proteins and could be a key to protein engineering improvement. The server presents the electrostatic free energy contribution of each polar-charged residue to the protein native state stability. Specific residues are suggested to be mutated for improving thermal stability. The choice of a residue is based on its fraction of side chain exposed to solvent and its positive free energy contribution, which tends to destabilize the protein native state. Any residue energy contribution can be shown as a function of pH condition. The web server is freely available at UNESP (São Paulo State University - DF/IBILCE): http://tksamc.df.ibilce.unesp.br and also on GitHub https://github.com/contessoto/tksamc.
Collapse
Affiliation(s)
- Vinícius G Contessoto
- Brazilian Bioethanol Science and Technology Laboratory - CTBE, Campinas, São Paulo, Brazil.,Department of Physics, Institute of Biosciences, Letters and Exact Sciences São Paulo State University - UNESP, São José do Rio Preto, São Paulo, Brazil
| | - Vinícius M de Oliveira
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences São Paulo State University - UNESP, São José do Rio Preto, São Paulo, Brazil
| | - Bruno R Fernandes
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences São Paulo State University - UNESP, São José do Rio Preto, São Paulo, Brazil
| | - Gabriel G Slade
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences São Paulo State University - UNESP, São José do Rio Preto, São Paulo, Brazil.,Theoretical Biophysics Laboratory, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro - UFTM, Uberaba, Minas Gerais, Brazil
| | - Vitor B P Leite
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences São Paulo State University - UNESP, São José do Rio Preto, São Paulo, Brazil
| |
Collapse
|
8
|
Zhou HX, Pang X. Electrostatic Interactions in Protein Structure, Folding, Binding, and Condensation. Chem Rev 2018; 118:1691-1741. [PMID: 29319301 DOI: 10.1021/acs.chemrev.7b00305] [Citation(s) in RCA: 485] [Impact Index Per Article: 80.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Charged and polar groups, through forming ion pairs, hydrogen bonds, and other less specific electrostatic interactions, impart important properties to proteins. Modulation of the charges on the amino acids, e.g., by pH and by phosphorylation and dephosphorylation, have significant effects such as protein denaturation and switch-like response of signal transduction networks. This review aims to present a unifying theme among the various effects of protein charges and polar groups. Simple models will be used to illustrate basic ideas about electrostatic interactions in proteins, and these ideas in turn will be used to elucidate the roles of electrostatic interactions in protein structure, folding, binding, condensation, and related biological functions. In particular, we will examine how charged side chains are spatially distributed in various types of proteins and how electrostatic interactions affect thermodynamic and kinetic properties of proteins. Our hope is to capture both important historical developments and recent experimental and theoretical advances in quantifying electrostatic contributions of proteins.
Collapse
Affiliation(s)
- Huan-Xiang Zhou
- Department of Chemistry and Department of Physics, University of Illinois at Chicago , Chicago, Illinois 60607, United States.,Department of Physics and Institute of Molecular Biophysics, Florida State University , Tallahassee, Florida 32306, United States
| | - Xiaodong Pang
- Department of Physics and Institute of Molecular Biophysics, Florida State University , Tallahassee, Florida 32306, United States
| |
Collapse
|
9
|
Martins de Oliveira V, Godoi Contessoto VD, Bruno da Silva F, Zago Caetano DL, Jurado de Carvalho S, Pereira Leite VB. Effects of pH and Salt Concentration on Stability of a Protein G Variant Using Coarse-Grained Models. Biophys J 2018; 114:65-75. [PMID: 29320697 PMCID: PMC5984902 DOI: 10.1016/j.bpj.2017.11.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/20/2017] [Accepted: 11/13/2017] [Indexed: 11/18/2022] Open
Abstract
The importance of charge-charge interactions in the thermal stability of proteins is widely known. pH and ionic strength play a crucial role in these electrostatic interactions, as well as in the arrangement of ionizable residues in each protein-folding stage. In this study, two coarse-grained models were used to evaluate the effect of pH and salt concentration on the thermal stability of a protein G variant (1PGB-QDD), which was chosen due to the quantity of experimental data exploring these effects on its stability. One of these coarse-grained models, the TKSA, calculates the electrostatic free energy of the protein in the native state via the Tanford-Kirkwood approach for each residue. The other one, CpHMD-SBM, uses a Coulomb screening potential in addition to the structure-based model Cα. Both models simulate the system in constant pH. The comparison between the experimental stability analysis and the computational results obtained by these simple models showed a good agreement. Through the TKSA method, the role of each charged residue in the protein's thermal stability was inferred. Using CpHMD-SBM, it was possible to evaluate salt and pH effects throughout the folding process. Finally, the computational pKa values were calculated by both methods and presented a good level of agreement with the experiments. This study provides, to our knowledge, new information and a comprehensive description of the electrostatic contribution to protein G stability.
Collapse
Affiliation(s)
- Vinícius Martins de Oliveira
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil
| | - Vinícius de Godoi Contessoto
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil; Brazilian Bioethanol Science and Technology Laboratory- (CTBE), Campinas, Brazil
| | - Fernando Bruno da Silva
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil
| | - Daniel Lucas Zago Caetano
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil
| | - Sidney Jurado de Carvalho
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil
| | - Vitor Barbanti Pereira Leite
- São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (Ibilce), Campus São José do Rio Preto, Brazil.
| |
Collapse
|
10
|
Abstract
BACKGROUND Variable domains of camelid heavy-chain antibodies, commonly named nanobodies, have high biotechnological potential. In view of their broad range of applications in research, diagnostics and therapy, engineering their stability is of particular interest. One important aspect is the improvement of thermostability, because it can have immediate effects on conformational stability, protease resistance and aggregation propensity of the protein. METHODS We analyzed the sequences and thermostabilities of 78 purified nanobody binders. From this data, potentially stabilizing amino acid variations were identified and studied experimentally. RESULTS Some mutations improved the stability of nanobodies by up to 6.1°C, with an average of 2.3°C across eight modified nanobodies. The stabilizing mechanism involves an improvement of both conformational stability and aggregation behavior, explaining the variable degree of stabilization in individual molecules. In some instances, variations predicted to be stabilizing actually led to thermal destabilization of the proteins. The reasons for this contradiction between prediction and experiment were investigated. CONCLUSIONS The results reveal a mutational strategy to improve the biophysical behavior of nanobody binders and indicate a species-specificity of nanobody architecture. GENERAL SIGNIFICANCE This study illustrates the potential and limitations of engineering nanobody thermostability by merging sequence information with stability data, an aspect that is becoming increasingly important with the recent development of high-throughput biophysical methods.
Collapse
|
11
|
Abstract
This article defines protein stability, emphasizes its importance and surveys the field of protein stabilization, with summary reference to a selection of 2009-2015 publications. One can enhance stability by, in particular, protein engineering strategies and by chemical modification (including conjugation) in solution. General protocols are set out on how to measure a given protein's (1) kinetic thermal stability, and (2) oxidative stability, and (3) how to undertake chemical modification of a protein in solution.
Collapse
Affiliation(s)
- Ciarán Ó'Fágáin
- School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
- National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland.
| |
Collapse
|
12
|
Spassov VZ, Yan L. A pH-dependent computational approach to the effect of mutations on protein stability. J Comput Chem 2016; 37:2573-87. [PMID: 27634390 DOI: 10.1002/jcc.24482] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/01/2016] [Accepted: 08/14/2016] [Indexed: 11/07/2022]
Abstract
This article describes a novel software implementation for high-throughput scanning mutagenesis with a focus on protein stability. The approach combines molecular mechanics calculations with calculations of protein ionization and a Gaussian-chain model of electrostatic interactions in unfolded state. Comprehensive testing demonstrates a state-of-the-art accuracy for predicted free energy differences on single, double, and triple mutations with a correlation coefficient R above 0.7, which takes about 1.5 min per mutation on a single CPU. Unlike most of existing in silico methods for fast mutagenesis, the stability changes are reported as a continuous function of solution pH for wide pH intervals. We also propose a novel in silico strategy for searching stabilized protein variants that is based on combinatorial scanning mutagenesis using representative amino acid types. Our in silico predictions are in excellent agreement with the hyper-stabilized variants of mesophilic cold shock protein found using the Proside method of direct evolution. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Velin Z Spassov
- BIOVIA, Dassault Systemes, 5005 Wateridge Vista Drive, San Diego, California, 92121.
| | - Lisa Yan
- BIOVIA, Dassault Systemes, 5005 Wateridge Vista Drive, San Diego, California, 92121
| |
Collapse
|
13
|
Luna-Martínez OD, Vidal-Limón A, Villalba-Velázquez MI, Sánchez-Alcalá R, Garduño-Juárez R, Uversky VN, Becerril B. Simple approach for ranking structure determining residues. PeerJ 2016; 4:e2136. [PMID: 27366642 PMCID: PMC4924125 DOI: 10.7717/peerj.2136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/25/2016] [Indexed: 12/30/2022] Open
Abstract
Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology.
Collapse
Affiliation(s)
- Oscar D Luna-Martínez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México , Cuernavaca , Morelos , Mexico
| | - Abraham Vidal-Limón
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica , San Luis Potosí , Mexico
| | | | - Rosalba Sánchez-Alcalá
- Instituto de Biotecnología, Universidad Nacional Autónoma de México , Cuernavaca , Morelos , Mexico
| | - Ramón Garduño-Juárez
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México , Cuernavaca , Morelos , Mexico
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL, United States; Institute for Biological Instrumentation, Russian Academy of Sciences, Puschino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins, Russian Academy of Sciences, St. Petersburg, Russia
| | - Baltazar Becerril
- Instituto de Biotecnología, Universidad Nacional Autónoma de México , Cuernavaca , Morelos , Mexico
| |
Collapse
|
14
|
Su JG, Han XM, Zhao SX, Hou YX, Li XY, Qi LS, Wang JH. Impacts of the charged residues mutation S48E/N62H on the thermostability and unfolding behavior of cold shock protein: insights from molecular dynamics simulation with Gō model. J Mol Model 2016; 22:91. [DOI: 10.1007/s00894-016-2958-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
|
15
|
Tych KM, Batchelor M, Hoffmann T, Wilson MC, Paci E, Brockwell DJ, Dougan L. Tuning protein mechanics through an ionic cluster graft from an extremophilic protein. SOFT MATTER 2016; 12:2688-2699. [PMID: 26809452 DOI: 10.1039/c5sm02938d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Proteins from extremophilic organisms provide excellent model systems to determine the role of non-covalent interactions in defining protein stability and dynamics as well as being attractive targets for the development of robust biomaterials. Hyperthermophilic proteins have a prevalence of salt bridges, relative to their mesophilic homologues, which are thought to be important for enhanced thermal stability. However, the impact of salt bridges on the mechanical properties of proteins is far from understood. Here, a combination of protein engineering, biophysical characterisation, single molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulations directly investigates the role of salt bridges in the mechanical stability of two cold shock proteins; BsCSP from the mesophilic organism Bacillus subtilis and TmCSP from the hyperthermophilic organism Thermotoga maritima. Single molecule force spectroscopy shows that at ambient temperatures TmCSP is mechanically stronger yet, counter-intuitively, its native state can withstand greater deformation before unfolding (i.e. it is mechanically soft) compared with BsCSP. MD simulations were used to identify the location and quantify the population of salt bridges, and reveal that TmCSP contains a larger number of highly occupied salt bridges than BsCSP. To test the hypothesis that salt-bridges endow these mechanical properties on the hyperthermophilic CSP, a charged triple mutant (CTM) variant of BsCSP was generated by grafting an ionic cluster from TmCSP into the BsCSP scaffold. As expected CTM is thermodynamically more stable and mechanically softer than BsCSP. We show that a grafted ionic cluster can increase the mechanical softness of a protein and speculate that it could provide a mechanical recovery mechanism and that it may be a design feature applicable to other proteins.
Collapse
Affiliation(s)
- Katarzyna M Tych
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
| | | | | | | | | | | | | |
Collapse
|
16
|
Novak MJ, Pattammattel A, Koshmerl B, Puglia M, Williams C, Kumar CV. “Stable-on-the-Table” Enzymes: Engineering the Enzyme–Graphene Oxide Interface for Unprecedented Kinetic Stability of the Biocatalyst. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01968] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marc J. Novak
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Ajith Pattammattel
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Brianna Koshmerl
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Megan Puglia
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Christina Williams
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Challa V. Kumar
- Department
of Chemistry,
Department of Molecular and Cell Biology, and Institute of Materials
Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| |
Collapse
|
17
|
Significantly improved thermostability of a reductase CgKR1 from Candida glabrata with a key mutation at Asp 138 for enhancing bioreduction of aromatic α-keto esters. J Biotechnol 2015; 203:54-61. [DOI: 10.1016/j.jbiotec.2015.02.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 02/14/2015] [Accepted: 02/28/2015] [Indexed: 01/03/2023]
|
18
|
Boulet-Audet M, Byrne B, Kazarian SG. High-throughput thermal stability analysis of a monoclonal antibody by attenuated total reflection FT-IR spectroscopic imaging. Anal Chem 2014; 86:9786-93. [PMID: 25221926 PMCID: PMC4218712 DOI: 10.1021/ac502529q] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/15/2014] [Indexed: 01/03/2023]
Abstract
The use of biotherapeutics, such as monoclonal antibodies, has markedly increased in recent years. It is thus essential that biotherapeutic production pipelines are as efficient as possible. For the production process, one of the major concerns is the propensity of a biotherapeutic antibody to aggregate. In addition to reducing bioactive material recovery, protein aggregation can have major effects on drug potency and cause highly undesirable immunological effects. It is thus essential to identify processing conditions which maximize recovery while avoiding aggregation. Heat resistance is a proxy for long-term aggregation propensity. Thermal stability assays are routinely performed using various spectroscopic and scattering detection methods. Here, we evaluated the potential of macro attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopic imaging as a novel method for the high-throughput thermal stability assay of a monoclonal antibody. This chemically specific visualization method has the distinct advantage of being able to discriminate between monomeric and aggregated protein. Attenuated total reflection is particularly suitable for selectively probing the bottom of vessels, where precipitated aggregates accumulate. With focal plane array detection, we tested 12 different buffer conditions simultaneously to assess the effect of pH and ionic strength on protein thermal stability. Applying the Finke model to our imaging kinetics allowed us to determine the rate constants of nucleation and autocatalytic growth. This analysis demonstrated the greater stability of our immunoglobulin at higher pH and moderate ionic strength, revealing the key role of electrostatic interactions. The high-throughput approach presented here has significant potential for analyzing the stability of biotherapeutics as well as any other biological molecules prone to aggregation.
Collapse
Affiliation(s)
- Maxime Boulet-Audet
- Department
of Chemical Engineering, Imperial College
London, South Kensington Campus, London, SW7 2AZ, United
Kingdom
- Department
of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom
| | - Bernadette Byrne
- Department
of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom
| | - Sergei G. Kazarian
- Department
of Chemical Engineering, Imperial College
London, South Kensington Campus, London, SW7 2AZ, United
Kingdom
| |
Collapse
|
19
|
Ordu EB, Sessions RB, Clarke AR, Karagüler NG. Effect of surface electrostatic interactions on the stability and folding of formate dehydrogenase from Candida methylica. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.05.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
20
|
Socha RD, Tokuriki N. Modulating protein stability - directed evolution strategies for improved protein function. FEBS J 2013; 280:5582-95. [PMID: 23711026 DOI: 10.1111/febs.12354] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/16/2013] [Accepted: 05/20/2013] [Indexed: 11/29/2022]
Abstract
Protein engineering is widely used to generate proteins with novel or enhanced function. However, manipulating protein function in the laboratory can prove laborious, protracted and challenging. Recent developments in the understanding of protein evolutionary dynamics have unveiled the full extent by which the evolution of function is limited by protein stability - a revelation that may be applied to protein engineering on a whole. Thus, strategies that modulate protein stability and reduce its constraining effects may facilitate the engineering of protein function. A combinatorial approach involving the introduction of compensatory mutations and manipulation of the stability threshold by chaperone buffering during directed evolution can improve the functional adaptation of a protein, thereby fostering our ability to attain ever-more ambitious protein functions in the laboratory.
Collapse
Affiliation(s)
- Raymond D Socha
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | | |
Collapse
|
21
|
Buttstedt A, Wostradowski T, Ihling C, Hause G, Sinz A, Schwarz E. Different morphology of amyloid fibrils originating from agitated and non-agitated conditions. Amyloid 2013; 20:86-92. [PMID: 23570235 DOI: 10.3109/13506129.2013.784962] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In vitro amyloid formation has been suggested to be a common property of any polypeptide chain depending on particular environmental conditions although in vivo amyloid fibril formation can be promoted by point mutations or triplet expansions. Here, we explored the influence of agitation on fibril formation of amyloidogenic alanine segments fused to Cold Shock Protein B (CspB) of Bacillus subtilis. While without agitation fibril formation was clearly dependent on the presence of an amyloidogenic alanine segment, fibril formation was independent of the amyloidogenic segment under agitation. Agitation even led to fibrillation of native CspB lacking the amyloidogenic segment. Furthermore, agitation not only influenced the kinetics of fibril formation, but also resulted in completely different fibril morphologies. These results indicate that experimental conditions can alter the region that undergoes a conformational change during in vitro fibrillation. Moreover, the data show that deductions from in vitro assays on in vivo fibril formation mechanisms are afflicted with a certain degree of uncertainty and therefore need to be cautiously discussed.
Collapse
Affiliation(s)
- Anja Buttstedt
- Facultatea de Zootehnie şi Biotehnologii, Universitatea de Ştiinţe Agricole şi Medicină Veterinară, Calea Mănăştur 3-5, 400372 Cluj-Napoca, Romania.
| | | | | | | | | | | |
Collapse
|
22
|
Naganathan AN. A Rapid, Ensemble and Free Energy Based Method for Engineering Protein Stabilities. J Phys Chem B 2013; 117:4956-64. [PMID: 23541220 DOI: 10.1021/jp401588x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Athi N. Naganathan
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India
| |
Collapse
|
23
|
Durdenko EV, Saburova EA. A special role of phosphate in the stability of lactate dehydrogenase against destruction by a polyelectrolyte. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2012. [DOI: 10.1134/s1068162012040061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
24
|
Speck J, Hecky J, Tam HK, Arndt KM, Einsle O, Müller KM. Exploring the molecular linkage of protein stability traits for enzyme optimization by iterative truncation and evolution. Biochemistry 2012; 51:4850-67. [PMID: 22545913 DOI: 10.1021/bi2018738] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stability of proteins is paramount for their therapeutic and industrial use and, thus, is a major task for protein engineering. Several types of chemical and physical stabilities are desired, and discussion revolves around whether each stability trait needs to be addressed separately and how specific and compatible stabilizing mutations act. We demonstrate a stepwise perturbation-compensation strategy, which identifies mutations rescuing the activity of a truncated TEM β-lactamase. Analyses relating structural stress with the external stresses of heat, denaturants, and proteases reveal our second-site suppressors as general stability centers that also improve the full-length enzyme. A library of lactamase variants truncated by 15 N-terminal and three C-terminal residues (Bla-NΔ15CΔ3) was subjected to activity selection and DNA shuffling. The resulting clone with the best in vivo performance harbored eight mutations, surpassed the full-length wild-type protein by 5.3 °C in T(m), displayed significantly higher catalytic activity at elevated temperatures, and showed delayed guanidine-induced denaturation. The crystal structure of this mutant was determined and provided insights into its stability determinants. Stepwise reconstitution of the N- and C-termini increased its thermal, denaturant, and proteolytic resistance successively, leading to a full-length enzyme with a T(m) increased by 15.3 °C and a half-denaturation concentration shifted from 0.53 to 1.75 M guanidinium relative to that of the wild type. These improvements demonstrate that iterative truncation-optimization cycles can exploit stability-trait linkages in proteins and are exceptionally suited for the creation of progressively stabilized variants and/or downsized proteins without the need for detailed structural or mechanistic information.
Collapse
Affiliation(s)
- Janina Speck
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | | | | | | | | | | |
Collapse
|
25
|
Ahmad S, Kumar V, Ramanand KB, Rao NM. Probing protein stability and proteolytic resistance by loop scanning: a comprehensive mutational analysis. Protein Sci 2012; 21:433-46. [PMID: 22246996 DOI: 10.1002/pro.2029] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/23/2011] [Accepted: 01/06/2012] [Indexed: 11/07/2022]
Abstract
Improvement in protein thermostability was often found to be associated with increase in its proteolytic resistance as revealed by comparative studies of homologous proteins from extremophiles or mutational studies. Structural elements of protein responsible for this association are not firmly established although loops are implicated indirectly due to their structural role in protein stability. To get a better insight, a detailed study of protein wide mutants and their influence on stability and proteolytic resistance would be helpful. To generate such a data set, a model protein, Bacillus subtilis lipase was subjected to loop scanning site-saturation mutagenesis on 86 positions spanning all loops including termini. Upon screening of ~16,000 clones, 17 single mutants with improved thermostability were identified with increment in apparent melting temperature (Tm(app) ) by 1-6°C resulting in an increase in free energy of unfolding (ΔG(unf) ) by 0.04-1.16 kcal/mol. Proteolytic resistance of all single mutants upon incubation with nonspecific protease, Subtilisin A, was determined. Upon comparison, post-proteolysis residual activities as well as kinetics of proteolysis of mutants showed excellent correlation with ΔG(unf) , (r > 0.9), suggesting that proteolysis was strongly correlated with the global stability of this protein. This significant correlation in this set, with least possible sequence changes (single aa substitution), while covering >60% of protein surface strongly argues for the covariance of these two variables. Compared to studies from extremophiles, with large sequence heterogeneity, the observed correlation in such a narrow sequence space (ΔΔG(unf) = 1.57 kcal⁻¹) justifies the robustness of this relation.
Collapse
Affiliation(s)
- Shoeb Ahmad
- Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research), Uppal Road, Hyderabad 500007, India
| | | | | | | |
Collapse
|
26
|
Yumerefendi H, Desravines DC, Hart DJ. Library-based methods for identification of soluble expression constructs. Methods 2011; 55:38-43. [DOI: 10.1016/j.ymeth.2011.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 01/10/2023] Open
|
27
|
Schmid FX. Lessons about Protein Stability from in vitro Selections. Chembiochem 2011; 12:1501-7. [DOI: 10.1002/cbic.201100018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Indexed: 11/07/2022]
|
28
|
Abstract
This article defines protein stability, emphasizes its importance and surveys some notable recent publications (2004-2008) in the field of protein stability/stabilization. Knowledge of the factors stabilizing proteins has emerged from denaturation studies and from study of thermophilic (and other extremophilic) proteins. One can enhance stability by protein engineering strategies, the judicious use of solutes and additives, immobilization, and chemical modification in solution. General protocols are set out on how to measure the kinetic thermal stability of a given protein and how to undertake chemical modification of a protein in solution.
Collapse
Affiliation(s)
- Ciarán O'Fágáin
- School of Biotechnology and National Centre for Sensor Research, Dublin City University, Dublin, Ireland.
| |
Collapse
|
29
|
Influence of the stability of a fused protein and its distance to the amyloidogenic segment on fibril formation. PLoS One 2010; 5:e15436. [PMID: 21124848 PMCID: PMC2990761 DOI: 10.1371/journal.pone.0015436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 09/21/2010] [Indexed: 11/19/2022] Open
Abstract
Conversion of native proteins into amyloid fibrils is irreversible and therefore it is difficult to study the interdependence of conformational stability and fibrillation by thermodynamic analyses. Here we approached this problem by fusing amyloidogenic poly-alanine segments derived from the N-terminal domain of the nuclear poly (A) binding protein PABPN1 with a well studied, reversibly unfolding protein, CspB from Bacillus subtilis. Earlier studies had indicated that CspB could maintain its folded structure in fibrils, when it was separated from the amyloidogenic segment by a long linker. When CspB is directly fused with the amyloidogenic segment, it unfolds because its N-terminal chain region becomes integrated into the fibrillar core, as shown by protease mapping experiments. Spacers of either 3 or 16 residues between CspB and the amyloidogenic segment were not sufficient to prevent this loss of CspB structure. Since the low thermodynamic stability of CspB (ΔG(D) = 12.4 kJ/mol) might be responsible for unfolding and integration of CspB into fibrils, fusions with a CspB mutant with enhanced thermodynamic stability (ΔG(D) = 26.9 kJ/mol) were studied. This strongly stabilized CspB remained folded and prevented fibril formation in all fusions. Our data show that the conformational stability of a linked, independently structured protein domain can control fibril formation.
Collapse
|
30
|
Maniccia AW, Yang W, Johnson JA, Li S, Tjong H, Zhou HX, Shaket LA, Yang JJ. Inverse tuning of metal binding affinity and protein stability by altering charged coordination residues in designed calcium binding proteins. PMC BIOPHYSICS 2009; 2:11. [PMID: 20025729 PMCID: PMC2816670 DOI: 10.1186/1757-5036-2-11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 12/21/2009] [Indexed: 11/10/2022]
Abstract
Ca(2+ )binding proteins are essential for regulating the role of Ca(2+ )in cell signaling and maintaining Ca(2+ )homeostasis. Negatively charged residues such as Asp and Glu are often found in Ca(2+ )binding proteins and are known to influence Ca(2+ )binding affinity and protein stability. In this paper, we report a systematic investigation of the role of local charge number and type of coordination residues in Ca(2+ )binding and protein stability using de novo designed Ca(2+ )binding proteins. The approach of de novo design was chosen to avoid the complications of cooperative binding and Ca(2+)-induced conformational change associated with natural proteins. We show that when the number of negatively charged coordination residues increased from 2 to 5 in a relatively restricted Ca(2+)-binding site, Ca(2+ )binding affinities increased by more than 3 orders of magnitude and metal selectivity for trivalent Ln(3+ )over divalent Ca(2+ )increased by more than 100-fold. Additionally, the thermal transition temperatures of the apo forms of the designed proteins decreased due to charge repulsion at the Ca(2+ )binding pocket. The thermal stability of the proteins was regained upon Ca(2+ )and Ln(3+ )binding to the designed Ca(2+ )binding pocket. We therefore observe a striking tradeoff between Ca(2+)/Ln(3+ )affinity and protein stability when the net charge of the coordination residues is varied. Our study has strong implications for understanding and predicting Ca(2+)-conferred thermal stabilization of natural Ca(2+ )binding proteins as well as for designing novel metalloproteins with tunable Ca(2+ )and Ln(3+ )binding affinity and selectivity.PACS codes: 05.10.-a.
Collapse
Affiliation(s)
- Anna Wilkins Maniccia
- Department of Chemistry, Center for Drug Design and Biotechnology, Georgia State University, Atlanta, GA 30303, USA
| | - Wei Yang
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Road 5625, Changchun, Jilin 130022, PR China
| | - Julian A Johnson
- Department of Chemistry, Center for Drug Design and Biotechnology, Georgia State University, Atlanta, GA 30303, USA
| | - Shunyi Li
- Department of Chemistry, Center for Drug Design and Biotechnology, Georgia State University, Atlanta, GA 30303, USA
| | - Harianto Tjong
- Department of Physics and Institute of Molecular Biophysics and School of Computational Science, Florida State University, Tallahassee, Florida 32306, USA
| | - Huan-Xiang Zhou
- Department of Physics and Institute of Molecular Biophysics and School of Computational Science, Florida State University, Tallahassee, Florida 32306, USA
| | - Lev A Shaket
- Department of Chemistry, Center for Drug Design and Biotechnology, Georgia State University, Atlanta, GA 30303, USA
| | - Jenny J Yang
- Department of Chemistry, Center for Drug Design and Biotechnology, Georgia State University, Atlanta, GA 30303, USA
| |
Collapse
|
31
|
Multivariate analysis of the sequence dependence of asparagine deamidation rates in peptides. Pharm Res 2009; 26:2417-28. [PMID: 19756976 DOI: 10.1007/s11095-009-9953-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2009] [Accepted: 08/07/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To develop a quantitative scheme to describe and predict asparagine deamidation in polypeptides using chemometric models employing reduced physicochemical property scales of amino acids. METHODS Deamidation rates for 306 pentapeptides, Gly-(n-1)-Asn-(n+1)-Gly, with the residues n-1 and n+1 varying over the naturally occurring amino acids, were obtained from literature. A multivariate regression technique, called projection to latent structures (PLS), was used to establish mathematical relationships between the physicochemical properties and the deamidation half-lives of the amino acid sequences. Three reduced physicochemical property scales, amide hydrogen exchange rates (to describe the relative acidity of the amide protons) and flexibility parameters for the sequences were evaluated for their predictive capacity. RESULTS The most effective descriptors of the deamidation half-lives were reduced-property parameters for amino acids called zz-scores. The PLS models with the reduced property scales, combined with the hydrogen exchange rates and/or flexibility parameters, explained more than 95% of the sequence-dependent variation in the deamidation half-lives. The amide hydrogen exchange rate (i.e., amide proton acidity), hydrophilicity, polarizability, and size of amino acids in position n+1 were found to be the principal factors governing the rate of deamidation. The effect of amino acids in position n-1 was found to be negligible. CONCLUSIONS Chemometric analysis employing reduced physicochemical parameters can provide an accurate prediction of chemical instability in peptides and proteins. The relative importance of these various factors could also be determined.
Collapse
|
32
|
Torrado M, Revuelta J, Gonzalez C, Corzana F, Bastida A, Asensio JL. Role of conserved salt bridges in homeodomain stability and DNA binding. J Biol Chem 2009; 284:23765-79. [PMID: 19561080 DOI: 10.1074/jbc.m109.012054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted to proteins from homeotherms. We have analyzed the influence of salt and hydrophobic bridges at these sites on the stability and DNA binding properties of human Hesx-1 homeodomain. Regarding the protein stability, our analysis shows that hydrophobic side chains are clearly preferred at positions 19/30 and 31/42. This stabilizing influence results from the more favorable packing of the aliphatic side chains with the protein core, as illustrated by the three-dimensional solution structure of a thermostable variant, herein reported. In contrast only polar side chains seem to be tolerated at positions 17/52. Interestingly, despite the significant influence of pairs 19/30 and 31/42 on the stability of the homeodomain, their effect on DNA binding ranges from modest to negligible. The observed lack of correlation between binding strength and conformational stability in the analyzed variants suggests that salt/hydrophobic bridges at these specific positions might have been employed by evolution to independently modulate both properties.
Collapse
Affiliation(s)
- Mario Torrado
- Departamento de Química Orgánica Biológica, Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas, 28006 Madrid
| | | | | | | | | | | |
Collapse
|
33
|
de Carvalho SJ, Fenley MO, da Silva FLB. Protein-ion binding process on finite macromolecular concentration. A Poisson-Boltzmann and Monte Carlo study. J Phys Chem B 2009; 112:16766-76. [PMID: 19368030 DOI: 10.1021/jp800783x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Electrostatic interactions are one of the key driving forces for protein-ligands complexation. Different levels for the theoretical modeling of such processes are available on the literature. Most of the studies on the Molecular Biology field are performed within numerical solutions of the Poisson-Boltzmann Equation and the dielectric continuum models framework. In such dielectric continuum models, there are two pivotal questions: (a) how the protein dielectric medium should be modeled, and (b) what protocol should be used when solving this effective Hamiltonian. By means of Monte Carlo (MC) and Poisson-Boltzmann (PB) calculations, we define the applicability of the PB approach with linear and nonlinear responses for macromolecular electrostatic interactions in electrolyte solution, revealing some physical mechanisms and limitations behind it especially due the raise of both macromolecular charge and concentration out of the strong coupling regime. A discrepancy between PB and MC for binding constant shifts is shown and explained in terms of the manner PB approximates the excess chemical potentials of the ligand, and not as a consequence of the nonlinear thermal treatment and/or explicit ion-ion interactions as it could be argued. Our findings also show that the nonlinear PB predictions with a low dielectric response well reproduce the pK shifts calculations carried out with an uniform dielectric model. This confirms and completes previous results obtained by both MC and linear PB calculations.
Collapse
Affiliation(s)
- Sidney Jurado de Carvalho
- Department of Physics, IBILCE/Unesp, 15054-000 - Rua Cristovão Colombo, 2265, Jd. Nazareth, São José do Rio Preto - SP, Brazil
| | | | | |
Collapse
|
34
|
Bloom JD, Glassman MJ. Inferring stabilizing mutations from protein phylogenies: application to influenza hemagglutinin. PLoS Comput Biol 2009; 5:e1000349. [PMID: 19381264 PMCID: PMC2664478 DOI: 10.1371/journal.pcbi.1000349] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 03/05/2009] [Indexed: 01/08/2023] Open
Abstract
One selection pressure shaping sequence evolution is the requirement that a
protein fold with sufficient stability to perform its biological functions. We
present a conceptual framework that explains how this requirement causes the
probability that a particular amino acid mutation is fixed during evolution to
depend on its effect on protein stability. We mathematically formalize this
framework to develop a Bayesian approach for inferring the stability effects of
individual mutations from homologous protein sequences of known phylogeny. This
approach is able to predict published experimentally measured mutational
stability effects (ΔΔG values) with an accuracy
that exceeds both a state-of-the-art physicochemical modeling program and the
sequence-based consensus approach. As a further test, we use our phylogenetic
inference approach to predict stabilizing mutations to influenza hemagglutinin.
We introduce these mutations into a temperature-sensitive influenza virus with a
defect in its hemagglutinin gene and experimentally demonstrate that some of the
mutations allow the virus to grow at higher temperatures. Our work therefore
describes a powerful new approach for predicting stabilizing mutations that can
be successfully applied even to large, complex proteins such as hemagglutinin.
This approach also makes a mathematical link between phylogenetics and
experimentally measurable protein properties, potentially paving the way for
more accurate analyses of molecular evolution. Mutating a protein frequently causes a change in its stability. As scientists, we
often care about these changes because we would like to engineer a
protein's stability or understand how its stability is impacted by a
naturally occurring mutation. Evolution also cares about mutational stability
changes, because a basic evolutionary requirement is that proteins remain
sufficiently stable to perform their biological functions. Our work is based on
the idea that it should be possible to use the fact that evolution selects for
stability to infer from related proteins the effects of specific mutations. We
show that we can indeed use protein evolutionary histories to computationally
predict previously measured mutational stability changes more accurately than
methods based on either of the two main existing strategies. We then test
whether we can predict mutations that increase the stability of hemagglutinin,
an influenza protein whose rapid evolution is partly responsible for the ability
of this virus to cause yearly epidemics. We experimentally create viruses
carrying predicted stabilizing mutations and find that several do in fact
improve the virus's ability to grow at higher temperatures. Our
computational approach may therefore be of use in understanding the evolution of
this medically important virus.
Collapse
Affiliation(s)
- Jesse D Bloom
- Division of Biology, California Institute of Technology, Pasadena, California, USA.
| | | |
Collapse
|
35
|
Schweiker KL, Makhatadze GI. Protein stabilization by the rational design of surface charge-charge interactions. Methods Mol Biol 2009; 490:261-83. [PMID: 19157087 DOI: 10.1007/978-1-59745-367-7_11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The design of proteins with increased stability has many important applications in biotechnology. In recent years, strategies involving directed evolution, sequence-based design, or computational design have proven successful for generating stabilized proteins. A brief overview of the various methods that have been used to increase protein stability is presented, followed by a detailed example of how the rational design of surface charge-charge interactions has provided a robust method for protein stabilization.
Collapse
Affiliation(s)
- Katrina L Schweiker
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | | |
Collapse
|
36
|
Schweiker KL, Makhatadze GI. A computational approach for the rational design of stable proteins and enzymes: optimization of surface charge-charge interactions. Methods Enzymol 2009; 454:175-211. [PMID: 19216927 DOI: 10.1016/s0076-6879(08)03807-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The design of stable proteins and enzymes is not only of particular biotechnological importance, but also addresses some important fundamental questions. While there are a number of different options available for designing or engineering stable proteins, the field of computational design provides fast and universal methods for stabilizing proteins of interest. One of the successful computational design strategies focuses on stabilizing proteins through the optimization of charge-charge interactions on the protein surface. By optimizing surface interactions, it is possible to alleviate some of the challenges that accompany efforts to redesign the protein core. The rational design of surface charge-charge interactions also allows one to optimize only the interactions that are distant from binding sites or active sites, making it possible to increase stability without adversely affecting activity. The optimization of surface charge-charge interactions is discussed in detail along with the experimental evidence to demonstrate that this is a robust and universal approach to designing proteins with enhanced stability.
Collapse
Affiliation(s)
- Katrina L Schweiker
- Department of Biology and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, USA
| | | |
Collapse
|
37
|
Radestock S, Gohlke H. Exploiting the Link between Protein Rigidity and Thermostability for Data-Driven Protein Engineering. Eng Life Sci 2008. [DOI: 10.1002/elsc.200800043] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
38
|
Vazquez-Figueroa E, Yeh V, Broering JM, Chaparro-Riggers JF, Bommarius AS. Thermostable variants constructed via the structure-guided consensus method also show increased stability in salts solutions and homogeneous aqueous-organic media. Protein Eng Des Sel 2008; 21:673-80. [PMID: 18799474 DOI: 10.1093/protein/gzn048] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Enzyme instability is a major factor preventing widespread adoption of enzymes for catalysis. Stability at high temperatures and in the presence of high salt concentrations and organic solvents would allow enzymes to be employed for transformations of compounds not readily soluble in low temperature or in purely aqueous systems. Furthermore, many redox enzymes require costly cofactors for function and consequently a robust cofactor regeneration system. In this work, we demonstrate how thermostable variants developed via an amino acid sequence-based consensus method also showed improved stability in solutions with high concentrations of kosmotropic and chaotropic salts and water-miscible organic solvents. This is invaluable to protein engineers since deactivation in salt solutions and organic solvents is not well understood, rendering a priori design of enzyme stability in these media difficult. Variants of glucose 1-dehydrogenase (GDH) were studied in solutions of different salts along the Hofmeister series and in the presence of varying amounts of miscible organic solvent. Only the most stable variants showed little deactivation dependence on salt-type and salt concentration. Kinetic stability, expressed by the deactivation rate constant k(d,obs), did not always correlate with thermodynamic stability of variants, as measured by melting temperature T(m). However, a strong correlation (R(2) > 0.95) between temperature stability and organic solvent stability was found when plotting T(50)(60) versus C(50)(60) values. All GDH variants retained stability in homogeneous aqueous-organic solvents with >80% v/v of organic solvent.
Collapse
Affiliation(s)
- E Vazquez-Figueroa
- School of Chemical and Biomolecular Engineering, Parker H. Petit Institute for Bioengineering and Bioscience, Atlanta, GA 30332-0363, USA
| | | | | | | | | |
Collapse
|
39
|
Changing the Determinants of Protein Stability from Covalent to Non-Covalent Interactions by In Vitro Evolution: A Structural and Energetic Analysis. J Mol Biol 2008; 381:1040-54. [DOI: 10.1016/j.jmb.2008.06.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 06/11/2008] [Indexed: 11/16/2022]
|
40
|
Kather I, Jakob RP, Dobbek H, Schmid FX. Increased folding stability of TEM-1 beta-lactamase by in vitro selection. J Mol Biol 2008; 383:238-51. [PMID: 18706424 DOI: 10.1016/j.jmb.2008.07.082] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 07/16/2008] [Accepted: 07/29/2008] [Indexed: 10/21/2022]
Abstract
In vitro selections of stabilized proteins lead to more robust enzymes and, at the same time, yield novel insights into the principles of protein stability. We employed Proside, a method of in vitro selection, to find stabilized variants of TEM-1 beta-lactamase from Escherichia coli. Proside links the increased protease resistance of stabilized proteins to the infectivity of a filamentous phage. Several libraries of TEM-1 beta-lactamase variants were generated by error-prone PCR, and variants with increased protease resistance were obtained by raising temperature or guanidinium chloride concentration during proteolytic selections. Despite the small size of phage libraries, several strongly stabilizing mutations could be obtained, and a manual combination of the best shifted the profiles for thermal unfolding and temperature-dependent inactivation of beta-lactamase by almost 20 degrees C to a higher temperature. The wild-type protein unfolds in two stages: from the native state via an intermediate of the molten-globule type to the unfolded form. In the course of the selections, the native protein was stabilized by 27 kJ mol(-1) relative to the intermediate and the cooperativity of unfolding was strongly increased. Three of our stabilizing replacements (M182T, A224V, and R275L) had been identified independently in naturally occurring beta-lactamase variants with extended substrate spectrum. In these variants, they acted as global suppressors of destabilizations caused by the mutations in the active site. The comparison between the crystal structure of our best variant and the crystal structure of the wild-type protein indicates that most of the selected mutations optimize helices and their packing. The stabilization by the E147G substitution is remarkable. It removes steric strain that originates from an overly tight packing of two helices in the wild-type protein. Such unfavorable van der Waals repulsions are not easily identified in crystal structures or by computational approaches, but they strongly reduce the conformational stability of a protein.
Collapse
Affiliation(s)
- Insa Kather
- Laboratorium für Biochemie und Bayreuther, Zentrum für Molekulare Biowissenschaften, Universität Bayreuth, 95440 Bayreuth, Germany
| | | | | | | |
Collapse
|
41
|
Tadokoro T, Matsushita K, Abe Y, Rohman MS, Koga Y, Takano K, Kanaya S. Remarkable Stabilization of a Psychrotrophic RNase HI by a Combination of Thermostabilizing Mutations Identified by the Suppressor Mutation Method. Biochemistry 2008; 47:8040-7. [DOI: 10.1021/bi800246e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takashi Tadokoro
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kyoko Matsushita
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yumi Abe
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Muhammad Saifur Rohman
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuichi Koga
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazufumi Takano
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shigenori Kanaya
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, and CREST, JST, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
42
|
Paschke M, Tiede C, Höhne W. Engineering a circularly permuted GFP scaffold for peptide presentation. J Mol Recognit 2008; 20:367-78. [PMID: 17918771 DOI: 10.1002/jmr.844] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The use of peptides as in vivo and in vitro ligand binding agents is hampered by the high flexibility, low stability and lack of intrinsic detection signal of peptide aptamers. Recent attempts to overcome these limitations included the integration of the binding peptide into a stable protein scaffold. In this paper, we present the optimization and testing of a circularly permuted variant of the green fluorescent protein (GFP). We examined the ability of the optimized scaffold to accept peptide insertions at three different regions. The three regions chosen are localized in close spatial proximity to each other and support different conformations of the inserted peptides. In all the three regions peptides with a biased, but still comprehensive, amino acid repertoire could be presented without disturbing the function of the optimized GFP-scaffold.
Collapse
Affiliation(s)
- Matthias Paschke
- Institut für Biochemie, Charité-Universitätsmedizin Berlin, Monbijoustrasse 20, D-10117 Berlin, Germany. mailto:
| | | | | |
Collapse
|
43
|
Vázquez-Figueroa E, Chaparro-Riggers J, Bommarius AS. Development of a Thermostable Glucose Dehydrogenase by a Structure-Guided Consensus Concept. Chembiochem 2007; 8:2295-301. [DOI: 10.1002/cbic.200700500] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
44
|
Mills IA, Flaugh SL, Kosinski-Collins MS, King JA. Folding and stability of the isolated Greek key domains of the long-lived human lens proteins gammaD-crystallin and gammaS-crystallin. Protein Sci 2007; 16:2427-44. [PMID: 17905830 PMCID: PMC2211709 DOI: 10.1110/ps.072970207] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The transparency of the eye lens depends on the high solubility and stability of the lens crystallin proteins. The monomeric gamma-crystallins and oligomeric beta-crystallins have paired homologous double Greek key domains, presumably evolved through gene duplication and fusion. Prior investigation of the refolding of human gammaD-crystallin revealed that the C-terminal domain folds first and nucleates the folding of the N-terminal domain. This result suggested that the human N-terminal domain might not be able to fold on its own. We constructed and expressed polypeptide chains corresponding to the isolated N- and C-terminal domains of human gammaD-crystallin, as well as the isolated domains of human gammaS-crystallin. Both circular dichroism and fluorescence spectroscopy indicated that the isolated domains purified from Escherichia coli were folded into native-like monomers. After denaturation, the isolated domains refolded efficiently at pH 7 and 37 degrees C into native-like structures. The in vitro refolding of all four domains revealed two kinetic phases, identifying partially folded intermediates for the Greek key motifs. When subjected to thermal denaturation, the isolated N-terminal domains were less stable than the full-length proteins and less stable than the C-terminal domains, and this was confirmed in equilibrium unfolding/refolding experiments. The decrease in stability of the N-terminal domain of human gammaD-crystallin with respect to the complete protein indicated that the interdomain interface contributes of 4.2 kcal/mol to the overall stability of this very long-lived protein.
Collapse
Affiliation(s)
- Ishara A Mills
- Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA
| | | | | | | |
Collapse
|
45
|
Baldwin RL. Energetics of protein folding. J Mol Biol 2007; 371:283-301. [PMID: 17582437 DOI: 10.1016/j.jmb.2007.05.078] [Citation(s) in RCA: 212] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 05/23/2007] [Accepted: 05/25/2007] [Indexed: 10/23/2022]
Abstract
The energetics of protein folding determine the 3D structure of a folded protein. Knowledge of the energetics is needed to predict the 3D structure from the amino acid sequence or to modify the structure by protein engineering. Recent developments are discussed: major factors are reviewed and auxiliary factors are discussed briefly. Major factors include the hydrophobic factor (burial of non-polar surface area) and van der Waals interactions together with peptide hydrogen bonds and peptide solvation. The long-standing model for the hydrophobic factor (free energy change proportional to buried non-polar surface area) is contrasted with the packing-desolvation model and the approximate nature of the proportionality between free energy and apolar surface area is discussed. Recent energetic studies of forming peptide hydrogen bonds (gas phase) are reviewed together with studies of peptide solvation in solution. Closer agreement is achieved between the 1995 values for protein unfolding enthalpies in vacuum given by Lazaridis-Archontis-Karplus and Makhatadze-Privalov when the solvation enthalpy of the peptide group is taken from electrostatic calculations. Auxiliary factors in folding energetics include salt bridges and side-chain hydrogen bonds, disulfide bridges, and propensities to form alpha-helices and beta-structure. Backbone conformational entropy is a major energetic factor which is discussed only briefly for lack of knowledge.
Collapse
Affiliation(s)
- Robert L Baldwin
- Department of Biochemistry, Beckman Center, Stanford University Medical Center, Stanford, CA 94305, USA.
| |
Collapse
|
46
|
Smith MD, Rosenow MA, Wang M, Allen JP, Szostak JW, Chaput JC. Structural insights into the evolution of a non-biological protein: importance of surface residues in protein fold optimization. PLoS One 2007; 2:e467. [PMID: 17520026 PMCID: PMC1867856 DOI: 10.1371/journal.pone.0000467] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 04/25/2007] [Indexed: 11/23/2022] Open
Abstract
Phylogenetic profiling of amino acid substitution patterns in proteins has led many to conclude that most structural information is carried by interior core residues that are solvent inaccessible. This conclusion is based on the observation that buried residues generally tolerate only conserved sequence changes, while surface residues allow more diverse chemical substitutions. This notion is now changing as it has become apparent that both core and surface residues play important roles in protein folding and stability. Unfortunately, the ability to identify specific mutations that will lead to enhanced stability remains a challenging problem. Here we discuss two mutations that emerged from an in vitro selection experiment designed to improve the folding stability of a non-biological ATP binding protein. These mutations alter two solvent accessible residues, and dramatically enhance the expression, solubility, thermal stability, and ligand binding affinity of the protein. The significance of both mutations was investigated individually and together, and the X-ray crystal structures of the parent sequence and double mutant protein were solved to a resolution limit of 2.8 and 1.65 A, respectively. Comparative structural analysis of the evolved protein to proteins found in nature reveals that our non-biological protein evolved certain structural features shared by many thermophilic proteins. This experimental result suggests that protein fold optimization by in vitro selection offers a viable approach to generating stable variants of many naturally occurring proteins whose structures and functions are otherwise difficult to study.
Collapse
Affiliation(s)
- Matthew D. Smith
- Center for BioOptical Nanotechnology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - Matthew A. Rosenow
- Center for BioOptical Nanotechnology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - Meitian Wang
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - James P. Allen
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| | - Jack W. Szostak
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - John C. Chaput
- Center for BioOptical Nanotechnology, The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, United States of America
| |
Collapse
|
47
|
Max KEA, Wunderlich M, Roske Y, Schmid FX, Heinemann U. Optimized variants of the cold shock protein from in vitro selection: structural basis of their high thermostability. J Mol Biol 2007; 369:1087-97. [PMID: 17481655 DOI: 10.1016/j.jmb.2007.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 04/03/2007] [Accepted: 04/04/2007] [Indexed: 11/20/2022]
Abstract
The bacterial cold shock proteins (Csp) are widely used as models for the experimental and computational analysis of protein stability. In a previous study, in vitro evolution was employed to identify strongly stabilizing mutations in Bs-CspB from Bacillus subtilis. The best variant found by this approach contained the mutations M1R, E3K and K65I, which raised the midpoint of thermal unfolding of Bs-CspB from 53.8 degrees C to 83.7 degrees C, and increased the Gibbs free energy of stabilization by 20.9 kJ mol(-1). Another selected variant with the two mutations A46K and S48R was stabilized by 11.1 kJ mol(-1). To elucidate the molecular basis of these stabilizations, we determined the crystal structures of these two Bs-CspB variants. The mutated residues are generally well ordered and provide additional stabilizing interactions, such as charge interactions, additional hydrogen bonds and improved side-chain packing. Several mutations improve the electrostatic interactions, either by the removal of unfavorable charges (E3K) or by compensating their destabilizing interactions (A46K, S48R). The stabilizing mutations are clustered at a contiguous surface area of Bs-CspB, which apparently is critically important for the stability of the beta-barrel structure but not well optimized in the wild-type protein.
Collapse
Affiliation(s)
- Klaas E A Max
- Makromolekulare Strukturen und Interaktionen, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | | | | | | | | |
Collapse
|
48
|
Gribenko AV, Makhatadze GI. Role of the Charge–Charge Interactions in Defining Stability and Halophilicity of the CspB Proteins. J Mol Biol 2007; 366:842-56. [PMID: 17188709 DOI: 10.1016/j.jmb.2006.11.061] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/20/2006] [Accepted: 11/17/2006] [Indexed: 11/28/2022]
Abstract
Charge-charge interactions on the surface of native proteins are important for protein stability and can be computationally redesigned in a rational way to modulate protein stability. Such computational effort led to an engineered protein, CspB-TB that has the same core as the mesophilic cold shock protein CspB-Bs from Bacillus subtilis, but optimized distribution of charge-charge interactions on the surface. The CspB-TB protein shows an increase in the transition temperature by 20 degrees C relative to the unfolding temperature of CspB-Bs. The CspB-TB and CspB-Bs protein pair offers a unique opportunity to further explore the energetics of charge-charge interactions as the substitutions at the same sequence positions are done in largely similar structural but different electrostatic environments. In particular we addressed two questions. What is the contribution of charge-charge interactions in the unfolded state to the protein stability and how amino acid substitutions modulate the effect of increase in ionic strength on protein stability (i.e. protein halophilicity). To this end, we experimentally measured the stabilities of over 100 variants of CspB-TB and CspB-Bs proteins with substitutions at charged residues. We also performed computational modeling of these protein variants. Analysis of the experimental and computational data allowed us to conclude that the charge-charge interactions in the unfolded state of two model proteins CspB-Bs and CspB-TB are not very significant and computational models that are based only on the native state structure can adequately, i.e. qualitatively (stabilizing versus destabilizing) and semi-quantitatively (relative rank order), predict the effects of surface charge neutralization or reversal on protein stability. We also show that the effect of ionic strength on protein stability (protein halophilicity) appears to be mainly due to the screening of the long-range charge-charge interactions.
Collapse
Affiliation(s)
- Alexey V Gribenko
- Department of Biochemistry and Molecular Biology, Penn State University, College of Medicine, Hershey, PA 17033, USA
| | | |
Collapse
|
49
|
Khechinashvili NN, Fedorov MV, Kabanov AV, Monti S, Ghio C, Soda K. Side Chain Dynamics and Alternative Hydrogen Bonding in the Mechanism of Protein Thermostabilization. J Biomol Struct Dyn 2006; 24:255-62. [PMID: 17054383 DOI: 10.1080/07391102.2006.10507117] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
To elucidate the mechanism of protein thermostabilization, the thermodynamic properties of small monomeric proteins from mesophilic and thermophilic organisms have been analyzed. Molecular dynamics simulations were employed in the study of dynamic features of charged and polar side chains of amino acid residues. The basic conclusion has been made: surface charged and polar side chains with high conformational mobility can form alternative hydrogen bonded (H-bonded) donor-acceptor pairs. The correlation between the quantitative content of alternative H-bonds per residue and the temperature of maximal thermostability of proteins has been found. The proposed mechanism of protein thermostabilization suggests continuous disruption of the primary H-bonds and formation of alternative ones, which maintain constant the enthalpy value in the native state and prevent a rapid increase of the conformational entropy with the rising temperature. The analysis of the results show that the more residues located in the N- and C-terminal regions and in the extended loops that are capable of forming alternative longer-range H-bonded pairs, the higher the protein thermostability.
Collapse
Affiliation(s)
- N N Khechinashvili
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.
| | | | | | | | | | | |
Collapse
|
50
|
Mozo-Villarías A, Cedano J, Querol E. Hydrophobicity Density Profiles to Predict Thermal Stability Enhancement in Proteins. Protein J 2006; 25:529-35. [PMID: 17106643 DOI: 10.1007/s10930-006-9039-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A hydrophobicity density is defined for a protein through its hydrophobicity tensor (similar to the inertia tensor), by using the Eisenberg hydrophobicity scale of the hydrophobic amino acids of a protein. This allows calculation of the radii of the corresponding hydrophobic ellipsoid of a protein and thus subsequently of its hydrophobic density. A hydrophobicity density profile is then obtained by simulating point mutations of each amino acid of a protein either to a high hydrophobicity value or to zero hydrophobicity. It is found that an increase in the hydrophobic density of the protein correlates with an increase of its mid-point transition temperature. From this profile it is possible to determine the amino acids or domain stretches in a protein that are most amenable to mutation in order to increase the thermal stability. The model is tested to predict the thermostabilisation effects of two mutations in a beta-glucanase: M29G and M29F. This model is compared with other hydrophobicity-related profiles described by other authors.
Collapse
Affiliation(s)
- Angel Mozo-Villarías
- Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, 25198, Lleida, Spain.
| | | | | |
Collapse
|