1
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Wang J, Chen S, Yuan Q, Chen J, Li D, Wang L, Yang Y. Predicting the effects of mutations on protein solubility using graph convolution network and protein language model representation. J Comput Chem 2024; 45:436-445. [PMID: 37933773 DOI: 10.1002/jcc.27249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/11/2023] [Accepted: 10/21/2023] [Indexed: 11/08/2023]
Abstract
Solubility is one of the most important properties of protein. Protein solubility can be greatly changed by single amino acid mutations and the reduced protein solubility could lead to diseases. Since experimental methods to determine solubility are time-consuming and expensive, in-silico methods have been developed to predict the protein solubility changes caused by mutations mostly through protein evolution information. However, these methods are slow since it takes long time to obtain evolution information through multiple sequence alignment. In addition, these methods are of low performance because they do not fully utilize protein 3D structures due to a lack of experimental structures for most proteins. Here, we proposed a sequence-based method DeepMutSol to predict solubility change from residual mutations based on the Graph Convolutional Neural Network (GCN), where the protein graph was initiated according to predicted protein structure from Alphafold2, and the nodes (residues) were represented by protein language embeddings. To circumvent the small data of solubility changes, we further pretrained the model over absolute protein solubility. DeepMutSol was shown to outperform state-of-the-art methods in benchmark tests. In addition, we applied the method to clinically relevant genes from the ClinVar database and the predicted solubility changes were shown able to separate pathogenic mutations. All of the data sets and the source code are available at https://github.com/biomed-AI/DeepMutSol.
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Affiliation(s)
- Jing Wang
- Guangzhou institute of technology, Xidian University, Guangzhou, China
- School of Computer Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Sheng Chen
- School of Computer Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Qianmu Yuan
- School of Computer Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Jianwen Chen
- School of Computer Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - Danping Li
- School of Telecommunications Engineering, Xidian University, Xi'an, China
| | - Lei Wang
- School of Electronic Engineering, Xidian University, Xi'an, China
| | - Yuedong Yang
- School of Computer Science and Engineering, Sun Yat-sen University, Guangzhou, China
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2
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McNutt E, Ke N, Thurman A, Eaglesham JB, Berkmen M. SAS: Split antibiotic selection for identifying chaperones that improve protein solubility. Heliyon 2024; 10:e26996. [PMID: 38495176 PMCID: PMC10943334 DOI: 10.1016/j.heliyon.2024.e26996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 02/15/2024] [Accepted: 02/22/2024] [Indexed: 03/19/2024] Open
Abstract
Background Heterologous expression of active, native-folded protein in Escherichia coli is critical in both academic research and biotechnology settings. When expressing non-native recombinant proteins in E. coli, obtaining soluble and active protein can be challenging. Numerous techniques can be used to enhance a proteins solubility, and largely focus on either altering the expression strain, plasmid vector features, growth conditions, or the protein coding sequence itself. However, there is no one-size-fits-all approach for addressing issues with protein solubility, and it can be both time and labor intensive to find a solution. An alternative approach is to use the co-expression of chaperones to assist with increasing protein solubility. By designing a genetic system where protein solubility is linked to viability, the appropriate protein folding factor can be selected for any given protein of interest. To this end, we developed a Split Antibiotic Selection (SAS) whereby an insoluble protein is inserted in-frame within the coding sequence of the hygromycin B resistance protein, aminoglycoside 7″-phosphotransferase-Ia (APH(7″)), to generate a tripartite fusion. By creating this tripartite fusion with APH(7″), the solubility of the inserted protein can be assessed by measuring the level of hygromycin B resistance of the cells. Results We demonstrate the functionality of this system using a known protein and co-chaperone pair, the human mitochondrial Hsp70 ATPase domain (ATPase70) and its co-chaperone human escort protein (Hep). Insertion of the insoluble ATPase70 within APH(7'') renders the tripartite fusion insoluble and results in sensitivity to hygromycin B. Antibiotic resistance can be rescued by expression of the co-chaperone Hep which assists in the folding of the APH(7'')-ATPase70-APH(7'') tripartite fusion and find that cellular hygromycin B resistance correlates with the total soluble fusion protein. Finally, using a diverse chaperone library, we find that SAS can be used in a pooled genetic selection to identify chaperones capable of improving client protein solubility. Conclusions The tripartite APH(7'') fusion links the in vivo solubility of the inserted protein of interest to hygromycin B resistance. This construct can be used in conjunction with a chaperone library to select for chaperones that increase the solubility of the inserted protein. This selection system can be applied to a variety of client proteins and eliminates the need to individually test chaperone-protein pairs to identify those that increase solubility.
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Affiliation(s)
- Emily McNutt
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Na Ke
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | | | | | - Mehmet Berkmen
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
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3
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Rahbar MR, Nezafat N, Morowvat MH, Savardashtaki A, Ghoshoon MB, Mehrabani-Zeinabad K, Ghasemi Y. Targeting Efficient Features of Urate Oxidase to Increase Its Solubility. Appl Biochem Biotechnol 2024:10.1007/s12010-023-04819-w. [PMID: 38308671 DOI: 10.1007/s12010-023-04819-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 02/05/2024]
Abstract
With the demand for mass production of protein drugs, solubility has become a serious issue. Extrinsic and intrinsic factors both affect this property. A homotetrameric cofactor-free urate oxidase (UOX) is not sufficiently soluble. To engineer UOX for optimum solubility, it is important to identify the most effective factor that influences solubility. The most effective feature to target for protein engineering was determined by measuring various solubility-related factors of UOX. A large library of homologous sequences was obtained from the databases. The data was reduced to six enzymes from different organisms. On the basis of various sequence- and structure-derived elements, the most and the least soluble enzymes were defined. To determine the best protein engineering target for modification, features of the most and least soluble enzymes were compared. Metabacillus fastidiosus UOX was the most soluble enzyme, while Agrobacterium globiformis UOX was the least soluble. According to the comparison-constant method, positive surface patches caused by arginine residue distribution are appropriate targets for modification. Two Arg to Ala mutations were introduced to the least soluble enzyme to test this hypothesis. These mutations significantly enhanced the mutant's solubility. While different algorithms produced conflicting results, it was difficult to determine which proteins were most and least soluble. Solubility prediction requires multiple algorithms based on these controversies. Protein surfaces should be investigated regionally rather than globally, and both sequence and structural data should be considered. Several other biotechnological products could be engineered using the data reduction and comparison-constant methods used in this study.
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Affiliation(s)
- Mohammad Reza Rahbar
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Navid Nezafat
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran
| | - Mohammad Hossein Morowvat
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran
| | - Amir Savardashtaki
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Bagher Ghoshoon
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran
| | - Kamran Mehrabani-Zeinabad
- Department of Biostatistics, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Younes Ghasemi
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, P.O. Box 71345-1583, Shiraz, Iran.
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4
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Quan N, Eguchi Y, Geiler-Samerotte K. Intra- FCY1: a novel system to identify mutations that cause protein misfolding. Front Genet 2023; 14:1198203. [PMID: 37745845 PMCID: PMC10512024 DOI: 10.3389/fgene.2023.1198203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Protein misfolding is a common intracellular occurrence. Most mutations to coding sequences increase the propensity of the encoded protein to misfold. These misfolded molecules can have devastating effects on cells. Despite the importance of protein misfolding in human disease and protein evolution, there are fundamental questions that remain unanswered, such as, which mutations cause the most misfolding? These questions are difficult to answer partially because we lack high-throughput methods to compare the destabilizing effects of different mutations. Commonly used systems to assess the stability of mutant proteins in vivo often rely upon essential proteins as sensors, but misfolded proteins can disrupt the function of the essential protein enough to kill the cell. This makes it difficult to identify and compare mutations that cause protein misfolding using these systems. Here, we present a novel in vivo system named Intra-FCY1 that we use to identify mutations that cause misfolding of a model protein [yellow fluorescent protein (YFP)] in Saccharomyces cerevisiae. The Intra-FCY1 system utilizes two complementary fragments of the yeast cytosine deaminase Fcy1, a toxic protein, into which YFP is inserted. When YFP folds, the Fcy1 fragments associate together to reconstitute their function, conferring toxicity in media containing 5-fluorocytosine and hindering growth. But mutations that make YFP misfold abrogate Fcy1 toxicity, thus strains possessing misfolded YFP variants rise to high frequency in growth competition experiments. This makes such strains easier to study. The Intra-FCY1 system cancels localization of the protein of interest, thus can be applied to study the relative stability of mutant versions of diverse cellular proteins. Here, we confirm this method can identify novel mutations that cause misfolding, highlighting the potential for Intra-FCY1 to illuminate the relationship between protein sequence and stability.
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Affiliation(s)
- N. Quan
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ, United States
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Y. Eguchi
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ, United States
| | - K. Geiler-Samerotte
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ, United States
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
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5
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Englund E, Schmidt M, Nava AA, Klass S, Keiser L, Dan Q, Katz L, Yuzawa S, Keasling JD. Biosensor Guided Polyketide Synthases Engineering for Optimization of Domain Exchange Boundaries. Nat Commun 2023; 14:4871. [PMID: 37573440 PMCID: PMC10423236 DOI: 10.1038/s41467-023-40464-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/28/2023] [Indexed: 08/14/2023] Open
Abstract
Type I modular polyketide synthases (PKSs) are multi-domain enzymes functioning like assembly lines. Many engineering attempts have been made for the last three decades to replace, delete and insert new functional domains into PKSs to produce novel molecules. However, inserting heterologous domains often destabilize PKSs, causing loss of activity and protein misfolding. To address this challenge, here we develop a fluorescence-based solubility biosensor that can quickly identify engineered PKSs variants with minimal structural disruptions. Using this biosensor, we screen a library of acyltransferase (AT)-exchanged PKS hybrids with randomly assigned domain boundaries, and we identify variants that maintain wild type production levels. We then probe each position in the AT linker region to determine how domain boundaries influence structural integrity and identify a set of optimized domain boundaries. Overall, we have successfully developed an experimentally validated, high-throughput method for making hybrid PKSs that produce novel molecules.
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Affiliation(s)
- Elias Englund
- Joint BioEnergy Institute, Emeryville, CA, USA
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Matthias Schmidt
- Joint BioEnergy Institute, Emeryville, CA, USA
- Institute of Applied Microbiology, Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
- Biological Systems and Engineering Division, Lawrence Berkeley National laboratory, Berkeley, CA, USA
| | - Alberto A Nava
- Joint BioEnergy Institute, Emeryville, CA, USA
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Sarah Klass
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National laboratory, Berkeley, CA, USA
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Leah Keiser
- Joint BioEnergy Institute, Emeryville, CA, USA
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA
| | - Qingyun Dan
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National laboratory, Berkeley, CA, USA
| | - Leonard Katz
- Joint BioEnergy Institute, Emeryville, CA, USA
- QB3, University of California, Berkeley, Berkeley, CA, USA
| | - Satoshi Yuzawa
- Joint BioEnergy Institute, Emeryville, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National laboratory, Berkeley, CA, USA
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
- Graduate school of Media and Governance, Keio University, Fujisawa, Kanagawa, Japan
| | - Jay D Keasling
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Biological Systems and Engineering Division, Lawrence Berkeley National laboratory, Berkeley, CA, USA.
- Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA.
- QB3, University of California, Berkeley, Berkeley, CA, USA.
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA.
- Center for Biosustainability, Danish Technical University, Lyngby, Denmark.
- Center for Synthetic biochemistry, Institute for Synthetic biology, Shenzhen Institute of Advanced Technology, Shenzhen, China.
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6
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Ahmed S, Manjunath K, Chattopadhyay G, Varadarajan R. Identification of stabilizing point mutations through mutagenesis of destabilized protein libraries. J Biol Chem 2022; 298:101785. [PMID: 35247389 PMCID: PMC8971944 DOI: 10.1016/j.jbc.2022.101785] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/18/2022] [Accepted: 02/26/2022] [Indexed: 01/22/2023] Open
Abstract
Although there have been recent transformative advances in the area of protein structure prediction, prediction of point mutations that improve protein stability remains challenging. It is possible to construct and screen large mutant libraries for improved activity or ligand binding. However, reliable screens for mutants that improve protein stability do not yet exist, especially for proteins that are well folded and relatively stable. Here, we demonstrate that incorporation of a single, specific, destabilizing mutation termed parent inactivating mutation into each member of a single-site saturation mutagenesis library, followed by screening for suppressors, allows for robust and accurate identification of stabilizing mutations. We carried out fluorescence-activated cell sorting of such a yeast surface display, saturation suppressor library of the bacterial toxin CcdB, followed by deep sequencing of sorted populations. We found that multiple stabilizing mutations could be identified after a single round of sorting. In addition, multiple libraries with different parent inactivating mutations could be pooled and simultaneously screened to further enhance the accuracy of identification of stabilizing mutations. Finally, we show that individual stabilizing mutations could be combined to result in a multi-mutant that demonstrated an increase in thermal melting temperature of about 20 °C, and that displayed enhanced tolerance to high temperature exposure. We conclude that as this method is robust and employs small library sizes, it can be readily extended to other display and screening formats to rapidly isolate stabilized protein mutants.
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Affiliation(s)
- Shahbaz Ahmed
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Kavyashree Manjunath
- Centre for Chemical Biology and Therapeutics, Institute of Stem Cell Science and Regenerative Medicine, Bangalore, India
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7
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Yoo JI, Navaratna TA, Kolence P, O’Malley MA. GPCR-FEX: A Fluoride-Based Selection System for Rapid GPCR Screening and Engineering. ACS Synth Biol 2022; 11:39-45. [PMID: 34979077 DOI: 10.1021/acssynbio.1c00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The directed evolution of proteins comprises a search of sequence space for variants that improve a target phenotype, yet identification of desirable variants is inherently limited by library size and screening ability. Selections that couple protein phenotype to cell viability accelerate identification of promising variants by depleting libraries of undesirable variants en masse. Here, we introduce GPCR-FEX, a stringent selection platform that couples G-protein coupled receptor (GPCR) signaling to expression of a fluoride ion exporter (FEX)-GFP fusion gene and concomitant cellular fluoride tolerance in yeast. The GPCR-FEX platform works to deplete inactive GPCR variants from the library prior to high-throughput fluorescence-based cell sorting for rapid, inexpensive screening of receptor libraries that sample an expanded sequence space. Using this system, FEX1 was placed under the control of either PFUS1 or PFIG1, promoters activated upon agonist binding by the native yeast GPCRs, Ste2p or Ste3p. Addition of a C-terminal degron to FEX1p enhanced the dynamic range of cell growth between agonist-treated and untreated cells. Using deep sequencing to enumerate population members, we show rapid selection of a previously engineered Ste2p receptor mutant strain over wild-type Ste2p in a model library enrichment experiment. Overall, the GPCR-FEX platform provides a mechanism to rapidly engineer GPCRs, which are important cellular sensors for synthetic biology.
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Affiliation(s)
- Justin I. Yoo
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Tejas A. Navaratna
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Patrick Kolence
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Michelle A. O’Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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8
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Ahmed S, Bhasin M, Manjunath K, Varadarajan R. Prediction of Residue-specific Contributions to Binding and Thermal Stability Using Yeast Surface Display. Front Mol Biosci 2022; 8:800819. [PMID: 35127820 PMCID: PMC8814602 DOI: 10.3389/fmolb.2021.800819] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 12/14/2021] [Indexed: 12/11/2022] Open
Abstract
Accurate prediction of residue burial as well as quantitative prediction of residue-specific contributions to protein stability and activity is challenging, especially in the absence of experimental structural information. This is important for prediction and understanding of disease causing mutations, and for protein stabilization and design. Using yeast surface display of a saturation mutagenesis library of the bacterial toxin CcdB, we probe the relationship between ligand binding and expression level of displayed protein, with in vivo solubility in E. coli and in vitro thermal stability. We find that both the stability and solubility correlate well with the total amount of active protein on the yeast cell surface but not with total amount of expressed protein. We coupled FACS and deep sequencing to reconstruct the binding and expression mean fluorescent intensity of each mutant. The reconstructed mean fluorescence intensity (MFIseq) was used to differentiate between buried site, exposed non active-site and exposed active-site positions with high accuracy. The MFIseq was also used as a criterion to identify destabilized as well as stabilized mutants in the library, and to predict the melting temperatures of destabilized mutants. These predictions were experimentally validated and were more accurate than those of various computational predictors. The approach was extended to successfully identify buried and active-site residues in the receptor binding domain of the spike protein of SARS-CoV-2, suggesting it has general applicability.
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Affiliation(s)
- Shahbaz Ahmed
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Munmun Bhasin
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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9
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Ortega C, Oppezzo P, Correa A. Overcoming the Solubility Problem in E. coli: Available Approaches for Recombinant Protein Production. Methods Mol Biol 2022; 2406:35-64. [PMID: 35089549 DOI: 10.1007/978-1-0716-1859-2_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Despite the importance of recombinant protein production in the academy and industrial fields, many issues concerning the expression of soluble and homogeneous products are still unsolved. Several strategies were developed to overcome these obstacles; however, at present, there is no magic bullet that can be applied for all cases. Indeed, several key expression parameters need to be evaluated for each protein. Among the different hosts for protein expression, Escherichia coli is by far the most widely used. In this chapter, we review many of the different tools employed to circumvent protein insolubility problems.
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Affiliation(s)
- Claudia Ortega
- Recombinant Protein Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Pablo Oppezzo
- Recombinant Protein Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Agustín Correa
- Recombinant Protein Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay.
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10
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Zutz A, Hamborg L, Pedersen LE, Kassem MM, Papaleo E, Koza A, Herrgård MJ, Jensen SI, Teilum K, Lindorff-Larsen K, Nielsen AT. A dual-reporter system for investigating and optimizing protein translation and folding in E. coli. Nat Commun 2021; 12:6093. [PMID: 34667164 PMCID: PMC8526717 DOI: 10.1038/s41467-021-26337-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 10/01/2021] [Indexed: 01/29/2023] Open
Abstract
Strategies for investigating and optimizing the expression and folding of proteins for biotechnological and pharmaceutical purposes are in high demand. Here, we describe a dual-reporter biosensor system that simultaneously assesses in vivo protein translation and protein folding, thereby enabling rapid screening of mutant libraries. We have validated the dual-reporter system on five different proteins and find an excellent correlation between reporter signals and the levels of protein expression and solubility of the proteins. We further demonstrate the applicability of the dual-reporter system as a screening assay for deep mutational scanning experiments. The system enables high throughput selection of protein variants with high expression levels and altered protein stability. Next generation sequencing analysis of the resulting libraries of protein variants show a good correlation between computationally predicted and experimentally determined protein stabilities. We furthermore show that the mutational experimental data obtained using this system may be useful for protein structure calculations.
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Affiliation(s)
- Ariane Zutz
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
| | - Louise Hamborg
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Lasse Ebdrup Pedersen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
| | - Maher M Kassem
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Elena Papaleo
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Anna Koza
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
| | - Markus J Herrgård
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
| | - Sheila Ingemann Jensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark
| | - Kaare Teilum
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet 220, 2800 Kgs, Lyngby, Denmark.
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11
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Ren C, Wen X, Mencius J, Quan S. An enzyme-based biosensor for monitoring and engineering protein stability in vivo. Proc Natl Acad Sci U S A 2021; 118:e2101618118. [PMID: 33753520 PMCID: PMC8020752 DOI: 10.1073/pnas.2101618118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Protein stability affects the physiological functions of proteins and is also a desirable trait in many protein engineering tasks, yet improving protein stability is challenging because of limitations in methods for directly monitoring protein stability in cells. Here, we report an in vivo stability biosensor wherein a protein of interest (POI) is inserted into a microbial enzyme (CysGA) that catalyzes the formation of endogenous fluorescent compounds, thereby coupling POI stability to simple fluorescence readouts. We demonstrate the utility of the biosensor in directed evolution to obtain stabilized, less aggregation-prone variants of two POIs (including nonamyloidogenic variants of human islet amyloid polypeptide). Beyond engineering applications, we exploited our biosensor in deep mutational scanning for experimental delineation of the stability-related contributions of all residues throughout the catalytic domain of a histone H3K4 methyltransferase, thereby revealing its scientifically informative stability landscape. Thus, our highly accessible method for in vivo monitoring of the stability of diverse proteins will facilitate both basic research and applied protein engineering efforts.
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Affiliation(s)
- Chang Ren
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Xin Wen
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Jun Mencius
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
| | - Shu Quan
- State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing, East China University of Science and Technology, Shanghai 200237, China
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12
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Nelson T, Liang S, Stains CI. A Luminescence-Based System for Identification of Genetically Encodable Inhibitors of Protein Aggregation. ACS OMEGA 2020; 5:12974-12978. [PMID: 32548481 PMCID: PMC7288563 DOI: 10.1021/acsomega.0c00779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
Molecules that disrupt protein aggregation represent potential tool compounds for the investigation of numerous human disease states. However, the identification of small molecules capable of disrupting protein aggregation has proven challenging. Larger biomolecules such as antibodies and proteins are promising alternatives due to their increased size. Despite the promise of protein-based inhibitors, generalizable assays are needed to more readily identify proteins capable of inhibiting aggregation. Herein, we utilize our previously reported self-assembling NanoLuc luciferase fragments to engineer a platform in which both detection reagents are expressed from the same plasmid, enabling facile co-transformation with a genetically encodable inhibitor. This streamlined system is capable of detecting changes in the solubility of amylin, huntingtin, and amyloid-β (Aβ) proteins in response to mutations, small-molecule inhibitors, and expression of genetically encodable inhibitors. This improved platform provides a means to begin to identify protein-based inhibitors with improved efficacy.
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Affiliation(s)
- Travis
J. Nelson
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Shuo Liang
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Cliff I. Stains
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
- Department
of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
- University
of Virginia Cancer Center, University of
Virginia, Charlottesville, Virginia 22904, United States
- Nebraska
Center for Integrated Biomolecular Communication, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
- Cancer
Genes and Molecular Regulation Program, Fred & Pamela Buffet Cancer
Center, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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13
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Nelson TJ, Truong T, Truong B, Bilyeu CV, Zhao J, Stains CI. A luminescence-based assay for monitoring changes in alpha-synuclein aggregation in living cells. RSC Adv 2020; 10:16675-16678. [PMID: 32489651 PMCID: PMC7266166 DOI: 10.1039/d0ra02720k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease is characterized by the accumulation of protein aggregates in the brain, termed Lewy bodies. Lewy bodies are predominantly composed of α-synuclein and mutations that increase the aggregation potential of α-synuclein have been associated with early on-set disease. Assays capable of reporting on the solubility of α-synuclein in living cells could provide a means to interrogate the influence of mutations on aggregation as well as identify small molecules capable of modulating the aggregation of α-synuclein. Herein, we repurpose our previously reported self-assembling NanoLuc luciferase fragments to engineer a platform for detecting α-synuclein solubility in living cells. This new assay is capable of reporting on changes in α-synuclein solubility caused by disease-relevant mutations as well as inhibitors of aggregation. In the long term, this new assay platform provides a means to investigate the influence of mutations on α-synuclein solubility as well as identify potential tool compounds capable of modulating α-synuclein aggregation.
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Affiliation(s)
- Travis J Nelson
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA
| | - Tiffany Truong
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA
| | - BaoLong Truong
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA
| | - Camden V Bilyeu
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA
| | - Jia Zhao
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA
| | - Cliff I Stains
- Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE 68588, USA.,Nebraska Center for Integrated Biomolecular Communication, University of Nebraska - Lincoln, Lincoln, NE 68588, USA.,Cancer Genes and Molecular Regulation Program, Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.,University of Virginia Cancer Center, University of Virginia, Charlottesville, VA, 22904, USA
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14
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Jong WSP, Ten Hagen-Jongman CM, Vikström D, Dontje W, Abdallah AM, de Gier JW, Bitter W, Luirink J. Mutagenesis-Based Characterization and Improvement of a Novel Inclusion Body Tag. Front Bioeng Biotechnol 2020; 7:442. [PMID: 31998707 PMCID: PMC6965018 DOI: 10.3389/fbioe.2019.00442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/11/2019] [Indexed: 12/13/2022] Open
Abstract
Whereas, bacterial inclusion bodies (IBs) for long were regarded as undesirable aggregates emerging during recombinant protein production, they currently receive attention as promising nanoparticulate biomaterials with diverse applications in biotechnology and biomedicine. We previously identified ssTorA, a signal sequence that normally directs protein export via the Tat pathway in E. coli, as a tag that induces the accumulation of fused proteins into IBs under overexpression conditions. Here, we used targeted mutagenesis to identify features and motifs being either critical or dispensable for IB formation. We found that IB formation is neither related to the function of ssTorA as a Tat-signal sequence nor is it a general feature of this family of signal sequences. IB formation was inhibited by co-overexpression of ssTorA binding chaperones TorD and DnaK and by amino acid substitutions that affect the propensity of ssTorA to form an α-helix. Systematic deletion experiments identified a minimal region of ssTorA required for IB formation in the center of the signal sequence. Unbiased genetic screening of a library of randomly mutagenized ssTorA sequences for reduced aggregation properties allowed us to pinpoint residues that are critical to sustain insoluble expression. Together, the data point to possible mechanisms for the aggregation of ssTorA fusions. Additionally, they led to the design of a tag with superior IB-formation properties compared to the original ssTorA sequence.
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Affiliation(s)
- Wouter S P Jong
- Abera Bioscience AB, Solna, Sweden.,Department of Molecular Microbiology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Vrije Universiteit, Amsterdam, Netherlands
| | - Corinne M Ten Hagen-Jongman
- Department of Molecular Microbiology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Vrije Universiteit, Amsterdam, Netherlands
| | | | - Wendy Dontje
- Department of Clinical Immunology and Rheumatology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Abdallah M Abdallah
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.,Bioscience Core Laboratory, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, Stockholm, Sweden
| | - Wilbert Bitter
- Department of Molecular Microbiology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Vrije Universiteit, Amsterdam, Netherlands.,Medical Microbiology and Infection Control, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, Netherlands
| | - Joen Luirink
- Abera Bioscience AB, Solna, Sweden.,Department of Molecular Microbiology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Vrije Universiteit, Amsterdam, Netherlands
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15
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Ren C, Wen X, Mencius J, Quan S. Selection and screening strategies in directed evolution to improve protein stability. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0288-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractProtein stability is not only fundamental for experimental, industrial, and therapeutic applications, but is also the baseline for evolving novel protein functions. For decades, stability engineering armed with directed evolution has continued its rapid development and inevitably poses challenges. Generally, in directed evolution, establishing a reliable link between a genotype and any interpretable phenotype is more challenging than diversifying genetic libraries. Consequently, we set forth in a small picture to emphasize the screening or selection techniques in protein stability-directed evolution to secure the link. For a more systematic review, two main branches of these techniques, namely cellular or cell-free display and stability biosensors, are expounded with informative examples.
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16
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Hot CoFi Blot: A High-Throughput Colony-Based Screen for Identifying More Thermally Stable Protein Variants. Methods Mol Biol 2019. [PMID: 31267459 DOI: 10.1007/978-1-4939-9624-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Highly soluble and stable proteins are desirable for many different applications, from basic science to reaching a cancer patient in the form of a biological drug. For X-ray crystallography-where production of a protein crystal might take weeks and even months-a stable protein sample of high purity and concentration can greatly increase the chances of producing a well-diffracting crystal. For a patient receiving a specific protein drug, its safety, efficacy, and even cost are factors affected by its solubility and stability. Increased protein expression and protein stability can be achieved by randomly altering the coding sequence. As the number of mutants generated might be overwhelming, a powerful protein expression and stability screen is required. In this chapter, we describe a colony filtration technology, which allows us to screen random mutagenesis libraries for increased thermal stability-the Hot CoFi blot. We share how to create the random mutagenesis library, how to perform the Hot CoFi blot, and how to identify more thermally stable clones. We use the Tobacco Etch Virus protease as a target to exemplify the procedure.
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17
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Paladin L, Piovesan D, Tosatto SCE. SODA: prediction of protein solubility from disorder and aggregation propensity. Nucleic Acids Res 2019; 45:W236-W240. [PMID: 28505312 PMCID: PMC7059794 DOI: 10.1093/nar/gkx412] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/09/2017] [Indexed: 01/08/2023] Open
Abstract
Solubility is an important, albeit not well understood, feature determining protein behavior. It is of paramount importance in protein engineering, where similar folded proteins may behave in very different ways in solution. Here we present SODA, a novel method to predict the changes of protein solubility based on several physico-chemical properties of the protein. SODA uses the propensity of the protein sequence to aggregate as well as intrinsic disorder, plus hydrophobicity and secondary structure preferences to estimate changes in solubility. It has been trained and benchmarked on two different datasets. The comparison to other recently published methods shows that SODA has state-of-the-art performance and is particularly well suited to predict mutations decreasing solubility. The method is fast, returning results for single mutations in seconds. A usage example estimating the full repertoire of mutations for a human germline antibody highlights several solubility hotspots on the surface. The web server, complete with RESTful interface and extensive help, can be accessed from URL: http://protein.bio.unipd.it/soda.
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Affiliation(s)
- Lisanna Paladin
- Department of Biomedical Sciences, University of Padua, Viale G. Colombo 3, 35121 Padova, Italy
| | - Damiano Piovesan
- Department of Biomedical Sciences, University of Padua, Viale G. Colombo 3, 35121 Padova, Italy
| | - Silvio C E Tosatto
- Department of Biomedical Sciences, University of Padua, Viale G. Colombo 3, 35121 Padova, Italy.,CNR Institute of Neuroscience, Viale G. Colombo 3, 35121 Padova, Italy
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18
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Abstract
Camelid-derived nanobodies are versatile tools for research, diagnostics, and therapeutics. Certain nanobodies can function as intrabodies and bind antigens within the eukaryotic cytosol. This capability is valuable for the development of intracellular probes and targeted gene therapies. Consequently, many attempts have been made to produce nanobodies that are intracellularly stable and resistant to aggregation. Pursuit of these intrabodies generally focuses on library design or nanobody selection method. Recent variations of library design have yielded diverse libraries capable of producing nanobodies against a wide variety of antigens. Novel screening methods have also been developed, yielding nanobodies with high affinity for intracellular antigens. These screening techniques can have advantages over phage display methods when nanobodies against intracellular antigens must be rapidly produced. Some intracellular screening methods convey the additional advantage of selecting for other desired intrabody characteristics, such as antiviral action or conditional stability. This review summarizes the recent developments in both library design and selection methods aimed at producing intrabodies.
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Affiliation(s)
- James Woods
- 1 Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
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19
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Nelson TJ, Zhao J, Stains CI. Utilizing split-NanoLuc luciferase fragments as luminescent probes for protein solubility in living cells. Methods Enzymol 2019; 622:55-66. [PMID: 31155065 DOI: 10.1016/bs.mie.2019.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protein misfolding and aggregation is now recognized as a hallmark of numerous human diseases. Standard bioanalytical techniques for monitoring protein aggregation generally rely on small molecules that provide an optical readout of fibril formation. While these methods have been useful for mechanistic studies, additional approaches are required to probe the equilibrium between soluble and insoluble protein within living systems. Such approaches could provide platforms for the identification of inhibitors of protein aggregation as well as a means to investigate the effect of mutations on protein aggregation in model systems. In this chapter, we provide detailed protocols for employing split-NanoLuc luciferase (Nluc) fragments to monitor changes in protein solubility in bacterial and mammalian cells. This sensitive luminesce-based assay can report upon changes in protein solubility induced by inhibitors and disease-relevant mutations.
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Affiliation(s)
- Travis J Nelson
- Department of Chemistry and Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Jia Zhao
- Department of Chemistry and Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Cliff I Stains
- Department of Chemistry and Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, United States; Cancer Genes and Molecular Recognition Program, Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, United States.
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20
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Du F, Kruziki MA, Zudock EJ, Zhang Y, Lown PS, Hackel BJ. Engineering an EGFR-binding Gp2 domain for increased hydrophilicity. Biotechnol Bioeng 2019; 116:526-535. [PMID: 30536855 PMCID: PMC6358468 DOI: 10.1002/bit.26893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/26/2018] [Accepted: 12/06/2018] [Indexed: 11/07/2022]
Abstract
The Gp2 domain is a 45 amino-acid scaffold that has been evolved for specific, high-affinity binding towards multiple targets and was proven useful in molecular imaging and biological antagonism. It was hypothesized that Gp2 may benefit from increased hydrophilicity for improved physiological distribution as well as for physicochemical robustness. We identified seven exposed hydrophobic sites for hydrophilic mutations and experimentally evaluated single mutants, which yielded six mutations that do not substantially hinder expression, binding affinity or specificity (to epidermal growth factor receptor), and thermal stability. Eight combinations of these mutations improved hydrophilicity relative to the parental Gp2 clone as assessed by reverse-phase high-performance liquid chromatography (p < 0.05). Secondary structures and refolding abilities of the selected single mutants and all multimutants were unchanged relative to the parental ligand. A variant with five hydrophobic-to-hydrophilic mutations was identified with enhanced solubility as well as reasonable binding affinity ( K d = 53-63 nM), recombinant yield (1.3 ± 0.8 mg/L), and thermal stability ( T m = 53 ± 3°C). An alternative variant with a cluster of three leucine-to-hydrophilic mutations was identified with increased solubility, nominally increased binding affinity ( K d = 13-28 nM) and reasonable thermal stability ( T m = 54.0 ± 0.6°C) but reduced yield (0.4 ± 0.3 mg/L). In addition, a ≥7°C increase in the midpoint of thermal denaturation was observed in one of the single mutants (T21N). These mutants highlight the physicochemical tradeoffs associated with hydrophobic-to-hydrophilic mutation within a small protein, improve the solubility and hydrophilicity of an existent molecular imaging probe, and provide a more hydrophilic starting point for discovery of new Gp2 ligands towards additional targets.
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Affiliation(s)
- Feifan Du
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
| | - Max A Kruziki
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
| | - Elizabeth J Zudock
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
| | - Yi Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
| | - Patrick S Lown
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
| | - Benjamin J Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota - Twin Cities, Minneapolis, Minnesota
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21
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Liu Y, Miao K, Li Y, Fares M, Chen S, Zhang X. A HaloTag-Based Multicolor Fluorogenic Sensor Visualizes and Quantifies Proteome Stress in Live Cells Using Solvatochromic and Molecular Rotor-Based Fluorophores. Biochemistry 2018; 57:4663-4674. [DOI: 10.1021/acs.biochem.8b00135] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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22
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Sachsenhauser V, Bardwell JC. Directed evolution to improve protein folding in vivo. Curr Opin Struct Biol 2018; 48:117-123. [PMID: 29278775 PMCID: PMC5880552 DOI: 10.1016/j.sbi.2017.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023]
Abstract
Recently, several innovative approaches have been developed that allow one to directly screen or select for improved protein folding in the cellular context. These methods have the potential of not just leading to a better understanding of the in vivo folding process, they may also allow for improved production of proteins of biotechnological interest.
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Affiliation(s)
- Veronika Sachsenhauser
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA
| | - James Ca Bardwell
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA; Howard Hughes Medical Institute, University of Michigan, 830 N. University, Ann Arbor, MI 48109, USA.
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23
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Fares M, Li Y, Liu Y, Miao K, Gao Z, Zhai Y, Zhang X. A Molecular Rotor-Based Halo-Tag Ligand Enables a Fluorogenic Proteome Stress Sensor to Detect Protein Misfolding in Mildly Stressed Proteome. Bioconjug Chem 2018; 29:215-224. [DOI: 10.1021/acs.bioconjchem.7b00763] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Matthew Fares
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Yinghao Li
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Yu Liu
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Kun Miao
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Zi Gao
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Yufeng Zhai
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Xin Zhang
- Department of Chemistry, ‡Department of Biochemistry and Molecular Biology, and §The Huck Institutes
of Life Sciences, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
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24
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Liu Y, Fares M, Dunham NP, Gao Z, Miao K, Jiang X, Bollinger SS, Boal AK, Zhang X. AgHalo: A Facile Fluorogenic Sensor to Detect Drug-Induced Proteome Stress. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702417] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yu Liu
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
| | - Matthew Fares
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
| | - Noah P. Dunham
- Department of Biochemistry and Molecular Biology; The Pennsylvania State University; University Park PA 16802 USA
| | - Zi Gao
- Department of Biochemistry and Molecular Biology; The Pennsylvania State University; University Park PA 16802 USA
| | - Kun Miao
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
| | - Xueyuan Jiang
- Department of Biochemistry and Molecular Biology; The Pennsylvania State University; University Park PA 16802 USA
| | - Samuel S. Bollinger
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
| | - Amie K. Boal
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
- Department of Biochemistry and Molecular Biology; The Pennsylvania State University; University Park PA 16802 USA
| | - Xin Zhang
- Department of Chemistry; The Pennsylvania State University; University Park PA 16802 USA
- Department of Biochemistry and Molecular Biology; The Pennsylvania State University; University Park PA 16802 USA
- The Huck Institutes of Life Sciences; The Pennsylvania State University; University Park PA 16802 USA
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25
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Liu Y, Fares M, Dunham NP, Gao Z, Miao K, Jiang X, Bollinger SS, Boal AK, Zhang X. AgHalo: A Facile Fluorogenic Sensor to Detect Drug-Induced Proteome Stress. Angew Chem Int Ed Engl 2017; 56:8672-8676. [PMID: 28557281 DOI: 10.1002/anie.201702417] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Indexed: 11/08/2022]
Abstract
Drug-induced proteome stress that involves protein aggregation may cause adverse effects and undermine the safety profile of a drug. Safety of drugs is regularly evaluated using cytotoxicity assays that measure cell death. However, these assays provide limited insights into the presence of proteome stress in live cells. A fluorogenic protein sensor is reported to detect drug-induced proteome stress prior to cell death. An aggregation prone Halo-tag mutant (AgHalo) was evolved to sense proteome stress through its aggregation. Detection of such conformational changes was enabled by a fluorogenic ligand that fluoresces upon AgHalo forming soluble aggregates. Using 5 common anticancer drugs, we exemplified detection of differential proteome stress before any cell death was observed. Thus, this sensor can be used to evaluate drug safety in a regime that the current cytotoxicity assays cannot cover and be generally applied to detect proteome stress induced by other toxins.
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Affiliation(s)
- Yu Liu
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Matthew Fares
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Noah P Dunham
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Zi Gao
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Kun Miao
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xueyuan Jiang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Samuel S Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Amie K Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xin Zhang
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.,Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.,The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
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26
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Emmerstorfer-Augustin A, Moser S, Pichler H. Screening for improved isoprenoid biosynthesis in microorganisms. J Biotechnol 2016; 235:112-20. [DOI: 10.1016/j.jbiotec.2016.03.051] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 03/29/2016] [Accepted: 03/31/2016] [Indexed: 11/26/2022]
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27
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Zhao J, Nelson TJ, Vu Q, Truong T, Stains CI. Self-Assembling NanoLuc Luciferase Fragments as Probes for Protein Aggregation in Living Cells. ACS Chem Biol 2016; 11:132-8. [PMID: 26492083 DOI: 10.1021/acschembio.5b00758] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Given the clear role of protein aggregation in human disease, there is a critical need for assays capable of quantifying protein aggregation in living systems. We hypothesized that the inherently low background and biocompatibility of luminescence signal readouts could provide a potential solution to this problem. Herein, we describe a set of self-assembling NanoLuc luciferase (Nluc) fragments that produce a tunable luminescence readout that is dependent upon the solubility of a target protein fused to the N-terminal Nluc fragment. To demonstrate this approach, we employed this assay in bacteria to assess mutations known to disrupt amyloid-beta (Aβ) aggregation as well as disease-relevant mutations associated with familial Alzheimer's diseases. The luminescence signal from these experiments correlates with the reported aggregation potential of these Aβ mutants and reinforces the increased aggregation potential of disease-relevant mutations in Aβ1-42. To further demonstrate the utility of this approach, we show that the effect of small molecule inhibitors on Aβ aggregation can be monitored using this system. In addition, we demonstrate that aggregation assays can be ported into mammalian cells. Taken together, these results indicate that this platform could be used to rapidly screen for mutations that influence protein aggregation as well as inhibitors of protein aggregation. This method offers a novel, genetically encodable luminescence readout of protein aggregation in living cells.
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Affiliation(s)
- Jia Zhao
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Travis J. Nelson
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Quyen Vu
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Tiffany Truong
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
| | - Cliff I. Stains
- Department
of Chemistry, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
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28
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Boock JT, King BC, Taw MN, Conrado RJ, Siu KH, Stark JC, Walker LP, Gibson DM, DeLisa MP. Repurposing a bacterial quality control mechanism to enhance enzyme production in living cells. J Mol Biol 2015; 427:1451-1463. [PMID: 25591491 DOI: 10.1016/j.jmb.2015.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/30/2014] [Accepted: 01/05/2015] [Indexed: 11/25/2022]
Abstract
Heterologous expression of many proteins in bacteria, yeasts, and plants is often limited by low titers of functional protein. To address this problem, we have created a two-tiered directed evolution strategy in Escherichia coli that enables optimization of protein production while maintaining high biological activity. The first tier involves a genetic selection for intracellular protein stability that is based on the folding quality control mechanism inherent to the twin-arginine translocation pathway, while the second is a semi-high-throughput screen for protein function. To demonstrate the utility of this strategy, we isolated variants of the endoglucanase Cel5A, from the plant-pathogenic fungus Fusarium graminearum, whose production was increased by as much as 30-fold over the parental enzyme. This gain in production was attributed to just two amino acid substitutions, and it was isolated after two iterations through the two-tiered approach. There was no significant tradeoff in activity on soluble or insoluble cellulose substrates. Importantly, by combining the folding filter afforded by the twin-arginine translocation quality control mechanism with a function-based screen, we show enrichment for variants with increased protein abundance in a manner that does not compromise catalytic activity, providing a highly soluble parent for engineering of improved or new function.
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Affiliation(s)
- Jason T Boock
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Brian C King
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
| | - May N Taw
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Robert J Conrado
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Ka-Hei Siu
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Jessica C Stark
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Larry P Walker
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Donna M Gibson
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA; Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Ithaca, NY 14853, USA
| | - Matthew P DeLisa
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
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Overcoming the solubility problem in E. coli: available approaches for recombinant protein production. Methods Mol Biol 2015; 1258:27-44. [PMID: 25447857 DOI: 10.1007/978-1-4939-2205-5_2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite the importance of recombinant protein production in academy and industrial fields, many issues concerning the expression of soluble and homogeneous product are still unsolved. Although several strategies were developed to overcome these obstacles, at present there is no magic bullet that can be applied for all cases. Indeed, several key expression parameters need to be evaluated for each protein. Among the different hosts for protein expression, Escherichia coli is by far the most widely used. In this chapter, we review many of the different tools employed to circumvent protein insolubility problems.
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Gupta A, Shrivastava N, Grover P, Singh A, Mathur K, Verma V, Kaur C, Chaudhary VK. A novel helper phage enabling construction of genome-scale ORF-enriched phage display libraries. PLoS One 2013; 8:e75212. [PMID: 24086469 PMCID: PMC3785514 DOI: 10.1371/journal.pone.0075212] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 08/08/2013] [Indexed: 11/19/2022] Open
Abstract
Phagemid-based expression of cloned genes fused to the gIIIP coding sequence and rescue using helper phages, such as VCSM13, has been used extensively for constructing large antibody phage display libraries. However, for randomly primed cDNA and gene fragment libraries, this system encounters reading frame problems wherein only one of 18 phages display the translated foreign peptide/protein fused to phagemid-encoded gIIIP. The elimination of phages carrying out-of-frame inserts is vital in order to improve the quality of phage display libraries. In this study, we designed a novel helper phage, AGM13, which carries trypsin-sensitive sites within the linker regions of gIIIP. This renders the phage highly sensitive to trypsin digestion, which abolishes its infectivity. For open reading frame (ORF) selection, the phagemid-borne phages are rescued using AGM13, so that clones with in-frame inserts express fusion proteins with phagemid-encoded trypsin-resistant gIIIP, which becomes incorporated into the phages along with a few copies of AGM13-encoded trypsin-sensitive gIIIP. In contrast, clones with out-of-frame inserts produce phages carrying only AGM13-encoded trypsin-sensitive gIIIP. Trypsin treatment of the phage population renders the phages with out-of-frame inserts non-infectious, whereas phages carrying in-frame inserts remain fully infectious and can hence be enriched by infection. This strategy was applied efficiently at a genome scale to generate an ORF-enriched whole genome fragment library from Mycobacterium tuberculosis, in which nearly 100% of the clones carried in-frame inserts after selection. The ORF-enriched libraries were successfully used for identification of linear and conformational epitopes for monoclonal antibodies specific to mycobacterial proteins.
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Affiliation(s)
- Amita Gupta
- Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
- * E-mail: (AG); (VKC)
| | - Nimisha Shrivastava
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Payal Grover
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Ajay Singh
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Kapil Mathur
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Vaishali Verma
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Charanpreet Kaur
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Vijay K. Chaudhary
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
- * E-mail: (AG); (VKC)
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Gul N, Linares DM, Ho FY, Poolman B. Evolved Escherichia coli strains for amplified, functional expression of membrane proteins. J Mol Biol 2013; 426:136-49. [PMID: 24041572 DOI: 10.1016/j.jmb.2013.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/08/2013] [Accepted: 09/10/2013] [Indexed: 10/26/2022]
Abstract
The major barrier to the physical characterization and structure determination of membrane proteins is low protein yield and/or low functionality in recombinant expression. The enteric bacterium Escherichia coli is the most widely employed organism for producing recombinant proteins. Beside several advantages of this expression host, one major drawback is that the protein of interest does not always adopt its native conformation and may end up in large insoluble aggregates. We describe a robust strategy to increase the likelihood of overexpressing membrane proteins in a functional state. The method involves fusion in tandem of green fluorescent protein and the erythromycin resistance protein (23S ribosomal RNA adenine N-6 methyltransferase, ErmC) to the C-terminus of a target membrane protein. The fluorescence of green fluorescent protein is used to report the folding state of the target protein, whereas ErmC is used to select for increased expression. By gradually increasing the erythromycin concentration of the medium and testing different membrane protein targets, we obtained a number of evolved strains of which four (NG2, NG3, NG5 and NG6) were characterized and their genome was fully sequenced. Strikingly, each of the strains carried a mutation in the hns gene, whose product is involved in genome organization and transcriptional silencing. The degree of expression of (membrane) proteins correlates with the severity of the hns mutation, but cells in which hns was deleted showed an intermediate expression performance. We propose that (partial) removal of the transcriptional silencing mechanism changes the levels of proteins essential for the functional overexpression of membrane proteins.
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Affiliation(s)
- Nadia Gul
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre and Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Daniel M Linares
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre and Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Franz Y Ho
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre and Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Netherlands Proteomics Centre and Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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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.
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Affiliation(s)
- Raymond D Socha
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
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33
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Hart DJ, Waldo GS. Library methods for structural biology of challenging proteins and their complexes. Curr Opin Struct Biol 2013; 23:403-8. [PMID: 23602357 DOI: 10.1016/j.sbi.2013.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 02/08/2023]
Abstract
Genetic engineering of constructs to improve solubility or stability is a common approach, but it is often unclear how to obtain improvements. When the domain composition of a target is poorly understood, or if there are insufficient structure data to guide sited directed mutagenesis, long iterative phases of subcloning or mutation and expression often prove unsuccessful despite much effort. Random library approaches can offer a solution to this problem and involve construction of large libraries of construct variants that are analysed via screens or selections for the desired phenotype. Huge improvements in construct behaviour can be achieved rapidly with no requirement for prior knowledge of the target. Here we review the development of these experimental strategies and recent successes.
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Affiliation(s)
- Darren J Hart
- EMBL Grenoble Outstation and Unit of Virus Host-Cell Interactions, UMI3265 UJF-EMBL-CNRS, Grenoble, France.
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34
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Screening libraries for improved solubility: using E. coli dihydrofolate reductase as a reporter. Methods Mol Biol 2013. [PMID: 23423901 DOI: 10.1007/978-1-62703-293-3_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Low protein solubility is a problem in many areas of protein science. Although chemical methods have been developed to solubilize proteins these are not always effective and add to the cost of producing the protein. One way of overcoming these difficulties is to evolve the protein to be more soluble. A major hurdle in this process is the ability to select mutant proteins with enhanced solubility from a large library of randomly mutated proteins. In this article, we describe such a method. The method relies on the fact that increasing the expression of dihydrofolate reductase (DHFR) makes Escherichia coli resistant to Trimethoprim (TMP). Proteins fused to DHFR will produce chimeras with altered levels of resistance to TMP. This variation in TMP resistance can be used to identify mutant proteins with enhanced solubility.
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Abstract
Molecular chaperones assist de novo protein folding and facilitate the refolding of stress-denatured proteins. The molecular chaperone concept was coined nearly 35 years ago, and since then, tremendous strides have been made in understanding how these factors support protein folding. Here, we focus on how various chaperone proteins were first identified to play roles in protein folding. Examples are used to illustrate traditional routes of chaperone discovery and point out their advantages and limitations. Recent advances, including the development of folding biosensors and promising methods for the stabilization of proteins in vivo, provide new routes for chaperone discovery.
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Affiliation(s)
- Shu Quan
- Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA.
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36
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Gregoire S, Irwin J, Kwon I. Techniques for Monitoring Protein Misfolding and Aggregation in Vitro and in Living Cells. KOREAN J CHEM ENG 2012; 29:693-702. [PMID: 23565019 PMCID: PMC3615250 DOI: 10.1007/s11814-012-0060-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protein misfolding and aggregation have been considered important in understanding many neurodegenerative diseases and recombinant biopharmaceutical production. Therefore, various traditional and modern techniques have been utilized to monitor protein aggregation in vitro and in living cells. Fibril formation, morphology and secondary structure content of amyloidogenic proteins in vitro have been monitored by molecular probes, TEM/AFM, and CD/FTIR analyses, respectively. Protein aggregation in living cells has been qualitatively or quantitatively monitored by numerous molecular folding reporters based on either fluorescent protein or enzyme. Aggregation of a target protein is directly correlated to the changes in fluorescence or enzyme activity of the folding reporter fused to the target protein, which allows non-invasive monitoring aggregation of the target protein in living cells. Advances in the techniques used to monitor protein aggregation in vitro and in living cells have greatly facilitated the understanding of the molecular mechanism of amyloidogenic protein aggregation associated with neurodegenerative diseases, optimizing culture conditions to reduce aggregation of biopharmaceuticals expressed in living cells, and screening of small molecule libraries in the search for protein aggregation inhibitors.
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Affiliation(s)
- Simpson Gregoire
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia22904
| | - Jacob Irwin
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia22904
| | - Inchan Kwon
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia22904
- Institutes on Aging, University of Virginia, Charlottesville, Virginia22904
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Monegal A, Olichon A, Bery N, Filleron T, Favre G, de Marco A. Single domain antibodies with VH hallmarks are positively selected during panning of llama (Lama glama) naïve libraries. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 36:150-156. [PMID: 21767565 DOI: 10.1016/j.dci.2011.06.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/24/2011] [Accepted: 06/26/2011] [Indexed: 05/31/2023]
Abstract
Independent variable domains with VH hallmarks have been repeatedly identified in immune and pre-immune VHH libraries. In some cases, stable independent VH domains have been also isolated in mouse and human recombinant antibody repertoires. However, we have come to realize that VHs were selected with a higher efficiency than VHHs during biopanning of a pre-immune (VHH) library. The biochemical and biophysical comparison did not indicate a presence of any feature that would favor the VH binders during the selection process. In contrast, selected VHHs seemed to be more stable than the VHs, ruling out the existence of a thermodynamically - favored VH sub-class. Therefore, we reasoned that a certain degree of thermodynamic instability may be beneficial for both displaying and expression of VH(H)s when the Sec-pathway is used for their secretion to avoid the cytoplasmic trapping of fast-folding polypeptides. Indeed, VHHs, but not VHs, were accumulated at higher concentrations when expressed fused to the dsbA leader peptide, a sequence that drives the linked polypeptides to the co-translational SRP secretion machinery. These data suggest that the thermodynamically favored VHHs can be lost during biopanning, as previously observed for DARPins and in contrast to the recombinant antibodies in scFv format.
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Affiliation(s)
- Ana Monegal
- Cogentech - Protein Chemistry Unit, IFOM-IEO Campus, Via Adamello 16, 20139 Milano, Italy
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38
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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
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D'Angelo S, Velappan N, Mignone F, Santoro C, Sblattero D, Kiss C, Bradbury ARM. Filtering "genic" open reading frames from genomic DNA samples for advanced annotation. BMC Genomics 2011; 12 Suppl 1:S5. [PMID: 21810207 PMCID: PMC3223728 DOI: 10.1186/1471-2164-12-s1-s5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background In order to carry out experimental gene annotation, DNA encoding open reading frames (ORFs) derived from real genes (termed "genic") in the correct frame is required. When genes are correctly assigned, isolation of genic DNA for functional annotation can be carried out by PCR. However, not all genes are correctly assigned, and even when correctly assigned, gene products are often incorrectly folded when expressed in heterologous hosts. This is a problem that can sometimes be overcome by the expression of protein fragments encoding domains, rather than full-length proteins. One possible method to isolate DNA encoding such domains would to "filter" complex DNA (cDNA libraries, genomic and metagenomic DNA) for gene fragments that confer a selectable phenotype relying on correct folding, with all such domains present in a complex DNA sample, termed the “domainome”. Results In this paper we discuss the preparation of diverse genic ORF libraries from randomly fragmented genomic DNA using ß-lactamase to filter out the open reading frames. By cloning DNA fragments between leader sequences and the mature ß-lactamase gene, colonies can be selected for resistance to ampicillin, conferred by correct folding of the lactamase gene. Our experiments demonstrate that the majority of surviving colonies contain genic open reading frames, suggesting that ß-lactamase is acting as a selectable folding reporter. Furthermore, different leaders (Sec, TAT and SRP), normally translocating different protein classes, filter different genic fragment subsets, indicating that their use increases the fraction of the “domainone” that is accessible. Conclusions The availability of ORF libraries, obtained with the filtering method described here, combined with screening methods such as phage display and protein-protein interaction studies, or with protein structure determination projects, can lead to the identification and structural determination of functional genic ORFs. ORF libraries represent, moreover, a useful tool to proceed towards high-throughput functional annotation of newly sequenced genomes.
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Affiliation(s)
- Sara D'Angelo
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
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40
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Makino T, Skretas G, Georgiou G. Strain engineering for improved expression of recombinant proteins in bacteria. Microb Cell Fact 2011; 10:32. [PMID: 21569582 PMCID: PMC3120638 DOI: 10.1186/1475-2859-10-32] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 05/14/2011] [Indexed: 01/17/2023] Open
Abstract
Protein expression in Escherichia coli represents the most facile approach for the preparation of non-glycosylated proteins for analytical and preparative purposes. So far, the optimization of recombinant expression has largely remained a matter of trial and error and has relied upon varying parameters, such as expression vector, media composition, growth temperature and chaperone co-expression. Recently several new approaches for the genome-scale engineering of E. coli to enhance recombinant protein expression have been developed. These methodologies now enable the generation of optimized E. coli expression strains in a manner analogous to metabolic engineering for the synthesis of low-molecular-weight compounds. In this review, we provide an overview of strain engineering approaches useful for enhancing the expression of hard-to-produce proteins, including heterologous membrane proteins.
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Affiliation(s)
- Tomohiro Makino
- Department of Chemical Engineering, The University of Texas at Austin, 78712, USA
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41
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Reetz MT, Zheng H. Manipulating the Expression Rate and Enantioselectivity of an Epoxide Hydrolase by Using Directed Evolution. Chembiochem 2011; 12:1529-35. [DOI: 10.1002/cbic.201100078] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Indexed: 11/06/2022]
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42
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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]
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43
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Schwab T, Sterner R. Stabilization of a metabolic enzyme by library selection in Thermus thermophilus. Chembiochem 2011; 12:1581-8. [PMID: 21455924 DOI: 10.1002/cbic.201000770] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Indexed: 11/11/2022]
Abstract
The anthranilate phosphoribosyl transferase from the hyperthermophilic archaeon Sulfolobus solfataricus (sAnPRT, encoded by strpD), which catalyzes the third step in tryptophan biosynthesis, is a thermostable homodimer with low enzymatic activity at room temperature. We have combined two mutations leading to the monomerization and two mutations leading to the activation of sAnPRT. The resulting "activated monomer" sAnPRT-I36E-M47D+D83G-F149S, which is much more labile than wild-type sAnPRT, was stabilized by a combination of random mutagenesis and metabolic library selection using the extremely thermophilic bacterium Thermus thermophilus as host. This approach led to the identification of five mutations that individually increased the thermal stability of sAnPRT-I36E-M47D+D83G-F149S by 1 to 8 °C, and by 13 °C when combined. The beneficial exchanges were located in different parts of the protein structure, but none of them led to the "re-dimerization" of the enzyme. We observed a negative correlation between thermal stability and catalytic activity of the mutants; this suggests that conformational flexibility is required for catalysis by sAnPRT.
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Affiliation(s)
- Thomas Schwab
- Institute of Biophysics and Physical Biochemistry, University of Regensburg, Regensburg, Germany
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44
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Sabogal A, Rio DC. A green fluorescent protein solubility screen in E. coli reveals domain boundaries of the GTP-binding domain in the P element transposase. Protein Sci 2011; 19:2210-8. [PMID: 20842711 DOI: 10.1002/pro.499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Guanosine triphosphate (GTP) binding and hydrolysis events often act as molecular switches in proteins, modulating conformational changes between active and inactive states in many signaling molecules and transport systems. The P element transposase of Drosophila melanogaster requires GTP binding to proceed along its reaction pathway, following initial site-specific DNA binding. GTP binding is unique to P elements and may represent a novel form of transpositional regulation, allowing the bound transposase to find a second site, looping the transposon DNA for strand cleavage and excision. The GTP-binding activity has been previously mapped to the central portion of the transposase protein; however, the P element transposase contains little sequence identity with known GTP-binding folds. To identify soluble, active transposase domains, a GFP solubility screen was used testing the solubility of random P element gene fragments in E. coli. The screen produced a single clone spanning known GTP-binding residues in the central portion of the transposase coding region. This clone, amino acids 275-409 in the P element transposase, was soluble, highly expressed in E.coli and active for GTP-binding activity, therefore is a candidate for future biochemical and structural studies. In addition, the chimeric screen revealed a minimal N-terminal THAP DNA-binding domain attached to an extended leucine zipper coiled-coil dimerization domain in the P element transposase, precisely delineating the DNA-binding and dimerization activities on the primary sequence. This study highlights the use of a GFP-based solubility screen on a large multidomain protein to identify highly expressed, soluble truncated domain subregions.
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Affiliation(s)
- Alex Sabogal
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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45
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Janocha S, Bichet A, Zöllner A, Bernhardt R. Substitution of lysine with glutamic acid at position 193 in bovine CYP11A1 significantly affects protein oligomerization and solubility but not enzymatic activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:126-31. [DOI: 10.1016/j.bbapap.2010.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 05/19/2010] [Accepted: 06/01/2010] [Indexed: 10/19/2022]
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46
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Behar G, Sole V, Defontaine A, Maillasson M, Quemener A, Jacques Y, Tellier C. Evolution of interleukin-15 for higher E. coli expression and solubility. Protein Eng Des Sel 2010; 24:283-90. [DOI: 10.1093/protein/gzq107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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47
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Enhancing the Stability and Solubility of the Glucocorticoid Receptor Ligand-Binding Domain by High-Throughput Library Screening. J Mol Biol 2010; 403:562-77. [DOI: 10.1016/j.jmb.2010.08.048] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 08/20/2010] [Accepted: 08/24/2010] [Indexed: 11/23/2022]
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48
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Tian Y, Deutsch C, Krishnamoorthy B. Scoring function to predict solubility mutagenesis. Algorithms Mol Biol 2010; 5:33. [PMID: 20929563 PMCID: PMC2958853 DOI: 10.1186/1748-7188-5-33] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 10/07/2010] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Mutagenesis is commonly used to engineer proteins with desirable properties not present in the wild type (WT) protein, such as increased or decreased stability, reactivity, or solubility. Experimentalists often have to choose a small subset of mutations from a large number of candidates to obtain the desired change, and computational techniques are invaluable to make the choices. While several such methods have been proposed to predict stability and reactivity mutagenesis, solubility has not received much attention. RESULTS We use concepts from computational geometry to define a three body scoring function that predicts the change in protein solubility due to mutations. The scoring function captures both sequence and structure information. By exploring the literature, we have assembled a substantial database of 137 single- and multiple-point solubility mutations. Our database is the largest such collection with structural information known so far. We optimize the scoring function using linear programming (LP) methods to derive its weights based on training. Starting with default values of 1, we find weights in the range [0,2] so that predictions of increase or decrease in solubility are optimized. We compare the LP method to the standard machine learning techniques of support vector machines (SVM) and the Lasso. Using statistics for leave-one-out (LOO), 10-fold, and 3-fold cross validations (CV) for training and prediction, we demonstrate that the LP method performs the best overall. For the LOOCV, the LP method has an overall accuracy of 81%. AVAILABILITY Executables of programs, tables of weights, and datasets of mutants are available from the following web page: http://www.wsu.edu/~kbala/OptSolMut.html.
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Affiliation(s)
- Ye Tian
- Department of Mathematics, Washington State University, Pullman, WA 99164, USA
| | | | - Bala Krishnamoorthy
- Department of Mathematics, Washington State University, Pullman, WA 99164, USA
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49
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Novel fluorescence-assisted whole-cell assay for engineering and characterization of proteases and their substrates. Appl Environ Microbiol 2010; 76:7500-8. [PMID: 20851955 DOI: 10.1128/aem.01558-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have developed a sensitive and highly efficient whole-cell methodology for quantitative analysis and screening of protease activity in vivo. The method is based on the ability of a genetically encoded protease to rescue a coexpressed short-lived fluorescent substrate reporter from cytoplasmic degradation and thereby confer increased whole-cell fluorescence in proportion to the protease's apparent activity in the Escherichia coli cytoplasm. We demonstrated that this system can reveal differences in the efficiency with which tobacco etch virus (TEV) protease processes different substrate peptides. In addition, when analyzing E. coli cells expressing TEV protease variants that differed in terms of their in vivo solubility, cells containing the most-soluble protease variant exhibited the highest fluorescence intensity. Furthermore, flow cytometry screening allowed for enrichment and subsequent identification of an optimal substrate peptide and protease variant from a large excess of cells expressing suboptimal variants (1:100,000). Two rounds of cell sorting resulted in a 69,000-fold enrichment and a 22,000-fold enrichment of the superior substrate peptide and protease variant, respectively. Our approach presents a new promising path forward for high-throughput substrate profiling of proteases, engineering of novel protease variants with desired properties (e.g., altered substrate specificity and improved solubility and activity), and identification of protease inhibitors.
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Mansell TJ, Linderman SW, Fisher AC, DeLisa MP. A rapid protein folding assay for the bacterial periplasm. Protein Sci 2010; 19:1079-90. [PMID: 20440843 DOI: 10.1002/pro.388] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An array of genetic screens and selections has been developed for reporting protein folding and solubility in the cytoplasm of living cells. However, there are currently no analogous folding assays for the bacterial periplasm, despite the significance of this compartment for the expression of recombinant proteins, especially those requiring important posttranslational modifications (e.g., disulfide bond formation). Here, we describe an engineered genetic selection for monitoring protein folding in the periplasmic compartment of Escherichia coli cells. In this approach, target proteins are sandwiched between an N-terminal signal recognition particle (SRP)-dependent signal peptide and a C-terminal selectable marker, TEM-1 beta-lactamase. The resulting chimeras are localized to the periplasmic space via the cotranslational SRP pathway. Using a panel of native and heterologous proteins, we demonstrate that the folding efficiency of various target proteins correlates directly with in vivo beta-lactamase activity and thus resistance to ampicillin. We also show that this reporter is useful for the discovery of extrinsic periplasmic factors (e.g., chaperones) that affect protein folding and for obtaining folding-enhanced proteins via directed evolution. Collectively, these data demonstrate that our periplasmic folding reporter is a powerful tool for screening and engineering protein folding in a manner that does not require any structural or functional information about the target protein.
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Affiliation(s)
- Thomas J Mansell
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA
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