1
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Cook KD, Tran T, Thomas VA, Devanaboyina SC, Rock DA, Pearson JT. Correlation of In Vitro Kinetic Stability to Preclinical In Vivo Pharmacokinetics for a Panel of Anti-PD-1 Monoclonal Antibody Interleukin 21 Mutein Immunocytokines. Drug Metab Dispos 2024; 52:228-235. [PMID: 38135505 DOI: 10.1124/dmd.123.001555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 12/24/2023] Open
Abstract
The development of therapeutic fusion protein drugs is often impeded by the unintended consequences that occur from fusing together domains from independent naturally occurring proteins, consequences such as altered biodistribution, tissue uptake, or rapid clearance and potential immunogenicity. For therapeutic fusion proteins containing globular domains, we hypothesized that aberrant in vivo behavior could be related to low kinetic stability of these domains leading to local unfolding and susceptibility to partial proteolysis and/or salvage and uptake. Herein we describe an assay to measure kinetic stability of therapeutic fusion proteins by way of their sensitivity to the protease thermolysin. The results indicate that in vivo pharmacokinetics of a panel of anti-programmed cell death protein 1 monocolonal antibody:interleukin 21 immunocytokines in both mice and nonhuman primates are highly correlated with their in vitro susceptibility to thermolysin-mediated proteolysis. This assay can be used as a tool to quickly identify in vivo liabilities of globular domains of therapeutic proteins, thus aiding in the optimization and development of new multispecific drug candidates. SIGNIFICANCE STATEMENT: This work describes a novel assay utilizing protein kinetic stability to identify preclinical in vivo pharmacokinetic liabilities of multispecific therapeutic fusion proteins. This provides an efficient, inexpensive method to ascertain inherent protein stability in vitro before conducting in vivo studies, which can rapidly increase the speed of preclinical drug development.
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Affiliation(s)
- Kevin D Cook
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Thuy Tran
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Veena A Thomas
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | | | - Dan A Rock
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
| | - Josh T Pearson
- Amgen Research, Pharmacokinetics & Drug Metabolism, South San Francisco, California
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2
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Pal S, Udgaonkar JB. Mutations of evolutionarily conserved aromatic residues suggest that misfolding of the mouse prion protein may commence in multiple ways. J Neurochem 2023; 167:696-710. [PMID: 37941487 DOI: 10.1111/jnc.16007] [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: 08/17/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
The misfolding of the mammalian prion protein from its α-helix rich cellular isoform to its β-sheet rich infectious isoform is associated with several neurodegenerative diseases. The determination of the structural mechanism by which misfolding commences, still remains an unsolved problem. In the current study, native-state hydrogen exchange coupled with mass spectrometry has revealed that the N state of the mouse prion protein (moPrP) at pH 4 is in dynamic equilibrium with multiple partially unfolded forms (PUFs) capable of initiating misfolding. Mutation of three evolutionarily conserved aromatic residues, Tyr168, Phe174, and Tyr217 present at the interface of the β2-α2 loop and the C-terminal end of α3 in the structured C-terminal domain of moPrP significantly destabilize the native state (N) of the protein. They also reduce the free energy differences between the N state and two PUFs identified as PUF1 and PUF2**. It is shown that PUF2** in which the β2-α2 loop and the C-terminal end of α3 are disordered, has the same stability as the previously identified PUF2*, but to have a very different structure. Misfolding can commence from both PUF1 and PUF2**, as it can from PUF2*. Hence, misfolding can commence and proceed in multiple ways from structurally distinct precursor conformations. The increased extents to which PUF1 and PUF2** are populated at equilibrium in the case of the mutant variants, greatly accelerate their misfolding. The results suggest that the three aromatic residues may have been evolutionarily selected to impede the misfolding of moPrP.
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Affiliation(s)
- Suman Pal
- Indian Institute of Science Education and Research Pune, Pune, India
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3
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Yan NL, Morgan GJ, Petrassi HM, Wilson IA, Kelly JW. Pharmacological stabilization of the native state of full-length immunoglobulin light chains to treat light chain amyloidosis. Curr Opin Chem Biol 2023; 75:102319. [PMID: 37279624 PMCID: PMC10523890 DOI: 10.1016/j.cbpa.2023.102319] [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: 02/01/2023] [Revised: 04/03/2023] [Accepted: 04/14/2023] [Indexed: 06/08/2023]
Abstract
Immunoglobulin light chain amyloidosis (AL) is a cancer of plasma cells that secrete unstable full-length immunoglobulin light chains. These light chains misfold and aggregate, often with aberrant endoproteolysis, leading to organ toxicity. AL is currently treated by pharmacological elimination of the clonal plasma cells. Since it remains difficult to completely kill these cells in the majority of patients, we seek a complementary drug that inhibits light chain aggregation, which should diminish organ toxicity. We discovered a small-molecule binding site on full-length immunoglobulin light chains by structurally characterizing hit stabilizers emerging from a high-throughput screen seeking small molecules that protect full-length light chains from conformational excursion-linked endoproteolysis. The x-ray crystallographic characterization of 7 structurally distinct hit native-state stabilizers provided a structure-based blueprint, reviewed herein, to design more potent stabilizers. This approach enabled us to transform hits with micromolar affinity into stabilizers with nanomolar dissociation constants that potently prevent light chain aggregation.
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Affiliation(s)
- Nicholas L Yan
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Gareth J Morgan
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA 02118, USA
| | - H Michael Petrassi
- Protego Biopharma, 10945 Vista Sorrento Parkway, San Diego, CA 92130, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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4
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Tsuboyama K, Dauparas J, Chen J, Laine E, Mohseni Behbahani Y, Weinstein JJ, Mangan NM, Ovchinnikov S, Rocklin GJ. Mega-scale experimental analysis of protein folding stability in biology and design. Nature 2023; 620:434-444. [PMID: 37468638 PMCID: PMC10412457 DOI: 10.1038/s41586-023-06328-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/14/2023] [Indexed: 07/21/2023]
Abstract
Advances in DNA sequencing and machine learning are providing insights into protein sequences and structures on an enormous scale1. However, the energetics driving folding are invisible in these structures and remain largely unknown2. The hidden thermodynamics of folding can drive disease3,4, shape protein evolution5-7 and guide protein engineering8-10, and new approaches are needed to reveal these thermodynamics for every sequence and structure. Here we present cDNA display proteolysis, a method for measuring thermodynamic folding stability for up to 900,000 protein domains in a one-week experiment. From 1.8 million measurements in total, we curated a set of around 776,000 high-quality folding stabilities covering all single amino acid variants and selected double mutants of 331 natural and 148 de novo designed protein domains 40-72 amino acids in length. Using this extensive dataset, we quantified (1) environmental factors influencing amino acid fitness, (2) thermodynamic couplings (including unexpected interactions) between protein sites, and (3) the global divergence between evolutionary amino acid usage and protein folding stability. We also examined how our approach could identify stability determinants in designed proteins and evaluate design methods. The cDNA display proteolysis method is fast, accurate and uniquely scalable, and promises to reveal the quantitative rules for how amino acid sequences encode folding stability.
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Affiliation(s)
- Kotaro Tsuboyama
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- PRESTO, Japan Science and Technology Agency, Tokyo, Japan
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
| | - Justas Dauparas
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Jonathan Chen
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- McCormick School of Engineering, Northwestern University, Evanston, IL, USA
| | - Elodie Laine
- Sorbonne Université, CNRS, IBPS, Laboratory of Computational and Quantitative Biology (LCQB), UMR 7238, Paris, France
| | - Yasser Mohseni Behbahani
- Sorbonne Université, CNRS, IBPS, Laboratory of Computational and Quantitative Biology (LCQB), UMR 7238, Paris, France
| | - Jonathan J Weinstein
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Niall M Mangan
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL, USA
| | - Sergey Ovchinnikov
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA, USA
| | - Gabriel J Rocklin
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA.
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5
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Gordon BH, Liu P, Whittington AC, Silvers R, Miller BG. Biochemical methods to map and quantify allosteric motions in human glucokinase. Methods Enzymol 2023; 685:433-459. [PMID: 37245911 PMCID: PMC10308428 DOI: 10.1016/bs.mie.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Allosteric regulation of protein function is ubiquitous in biology. Allostery originates from ligand-mediated alterations in polypeptide structure and/or dynamics, which produce a cooperative kinetic or thermodynamic response to changing ligand concentrations. Establishing a mechanistic description of individual allosteric events requires both mapping the relevant changes in protein structure and quantifying the rates of differential conformational dynamics in the absence and presence of effectors. In this chapter, we describe three biochemical approaches to understand the dynamic and structural signatures of protein allostery using the well-established cooperative enzyme glucokinase as a case study. The combined application of pulsed proteolysis, biomolecular nuclear magnetic resonance spectroscopy and hydrogen-deuterium exchange mass spectrometry offers complementary information that can used to establish molecular models for allosteric proteins, especially when differential protein dynamics are involved.
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Affiliation(s)
- Blaine H Gordon
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States; Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Peilu Liu
- Protein Analytical Chemistry, Genentech Inc., South San Francisco, CA, United States
| | - A Carl Whittington
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States; Department of Biological Science, Florida State University, Tallahassee, FL, United States
| | - Robert Silvers
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States; Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, United States
| | - Brian G Miller
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, United States.
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6
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Pacheco-Garcia JL, Cagiada M, Tienne-Matos K, Salido E, Lindorff-Larsen K, L. Pey A. Effect of naturally-occurring mutations on the stability and function of cancer-associated NQO1: Comparison of experiments and computation. Front Mol Biosci 2022; 9:1063620. [PMID: 36504709 PMCID: PMC9730889 DOI: 10.3389/fmolb.2022.1063620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/03/2022] [Indexed: 11/25/2022] Open
Abstract
Recent advances in DNA sequencing technologies are revealing a large individual variability of the human genome. Our capacity to establish genotype-phenotype correlations in such large-scale is, however, limited. This task is particularly challenging due to the multifunctional nature of many proteins. Here we describe an extensive analysis of the stability and function of naturally-occurring variants (found in the COSMIC and gnomAD databases) of the cancer-associated human NAD(P)H:quinone oxidoreductase 1 (NQO1). First, we performed in silico saturation mutagenesis studies (>5,000 substitutions) aimed to identify regions in NQO1 important for stability and function. We then experimentally characterized twenty-two naturally-occurring variants in terms of protein levels during bacterial expression, solubility, thermal stability, and coenzyme binding. These studies showed a good overall correlation between experimental analysis and computational predictions; also the magnitude of the effects of the substitutions are similarly distributed in variants from the COSMIC and gnomAD databases. Outliers in these experimental-computational genotype-phenotype correlations remain, and we discuss these on the grounds and limitations of our approaches. Our work represents a further step to characterize the mutational landscape of NQO1 in the human genome and may help to improve high-throughput in silico tools for genotype-phenotype correlations in this multifunctional protein associated with disease.
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Affiliation(s)
| | - Matteo Cagiada
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Eduardo Salido
- Center for Rare Diseases (CIBERER), Hospital Universitario de Canarias, Universidad de la Laguna, La Laguna, TenerifeTenerife, Spain
| | - Kresten Lindorff-Larsen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, Copenhagen, Denmark
| | - Angel L. Pey
- Departamento de Química Física, Unidad de Excelencia en Química Aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Universidad de Granada, Granada, Spain,*Correspondence: Angel L. Pey,
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7
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Xu LL, Gao HY, Yang F, Wen YQ, Zhang HW, Lin H, Li ZX, Gasset M. Major shrimp allergen peptidomics signatures and potential biomarkers of heat processing. Food Chem 2022; 382:132567. [PMID: 35247661 DOI: 10.1016/j.foodchem.2022.132567] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/04/2022]
Abstract
It is important to develop tools that can be used to understand the effects of processing on allergenic foods in order to achieve personalized food labeling. To evaluate the effect of heating on the allergy-relevant structural properties of tropomyosin (TM), arginine kinase (AK), myosin light chain (MLC) and sarcoplasmic calcium-binding protein (SCP) shrimp allergens, trypsin digests of raw, fried and baked shrimp extracts were analyzed by peptidomics and epitope correlations. Processing altered the number of peptides released from the distinct allergens, and each treatment generated a specific epitope-matched peptide allergen fingerprint. Among the four allergens, TM led to a number of released peptides and epitope changes being detected, and AK provided the epitope-matched 331MGLTEFQAVK340 sequence as a common differentiating peptide for heat processing. These results provide new views on the structural effects of processing on major shrimp allergens and peptide candidates as processing biomarkers.
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Affiliation(s)
- Li Li Xu
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China; Institute of Physical Chemistry Rocasolano (IQFR), Spanish National Research Council (CSIC), 28006 Madrid, Spain
| | - Hong Yan Gao
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China
| | - Fan Yang
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China
| | - Yun Qi Wen
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China
| | - Hong Wei Zhang
- Technology Center of Qingdao Customs District, 70 Qutangxia Road, Qingdao 266002, Shandong Province, China
| | - Hong Lin
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China
| | - Zhen Xing Li
- College of Food Science and Engineering, Ocean University of China, 5 Yushan Road 5, Qingdao 266003, Shandong Province, China
| | - María Gasset
- Institute of Physical Chemistry Rocasolano (IQFR), Spanish National Research Council (CSIC), 28006 Madrid, Spain.
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8
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Takahashi D, Matsunaga E, Yamashita T, Caaveiro JM, Abe Y, Ueda T. Compound screening identified gossypetin and isoquercitrin as novel inhibitors for amyloid fibril formations of Vλ6 proteins associated with AL amyloidosis. Biochem Biophys Res Commun 2022; 596:22-28. [DOI: 10.1016/j.bbrc.2022.01.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/02/2022]
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9
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Petrotchenko EV, Borchers CH. Protein Chemistry Combined with Mass Spectrometry for Protein Structure Determination. Chem Rev 2021; 122:7488-7499. [PMID: 34968047 DOI: 10.1021/acs.chemrev.1c00302] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The advent of soft-ionization mass spectrometry for biomolecules has opened up new possibilities for the structural analysis of proteins. Combining protein chemistry methods with modern mass spectrometry has led to the emergence of the distinct field of structural proteomics. Multiple protein chemistry approaches, such as surface modification, limited proteolysis, hydrogen-deuterium exchange, and cross-linking, provide diverse and often orthogonal structural information on the protein systems studied. Combining experimental data from these various structural proteomics techniques provides a more comprehensive examination of the protein structure and increases confidence in the ultimate findings. Here, we review various types of experimental data from structural proteomics approaches with an emphasis on the use of multiple complementary mass spectrometric approaches to provide experimental constraints for the solving of protein structures.
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Affiliation(s)
- Evgeniy V Petrotchenko
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada.,Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Christoph H Borchers
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada.,Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia.,Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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10
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Pacheco-Garcia JL, Loginov D, Rizzuti B, Vankova P, Neira JL, Kavan D, Mesa-Torres N, Guzzi R, Man P, Pey AL. A single evolutionarily divergent mutation determines the different FAD-binding affinities of human and rat NQO1 due to site-specific phosphorylation. FEBS Lett 2021; 596:29-41. [PMID: 34817874 DOI: 10.1002/1873-3468.14238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 12/13/2022]
Abstract
The phosphomimetic mutation S82D in the cancer-associated, FAD-dependent human NADP(H):quinone oxidoreductase 1 (hNQO1) causes a decrease in flavin-adenine dinucleotide-binding affinity and intracellular stability. We test in this work whether the evolutionarily recent neutral mutation R80H in the vicinity of S82 may alter the strong functional effects of S82 phosphorylation through electrostatic interactions. We show using biophysical and bioinformatic analyses that the reverse mutation H80R prevents the effects of S82D phosphorylation on hNQO1 by modulating the local stability. Consistently, in rat NQO1 (rNQO1) which contains R80, the effects of phosphorylation were milder, resembling the behaviour found in hNQO1 when this residue was humanized in rNQO1 (by the R80H mutation). Thus, apparently neutral and evolutionarily divergent mutations may determine the functional response of mammalian orthologues towards phosphorylation.
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Affiliation(s)
| | - Dmitry Loginov
- Institute of Microbiology of the Czech Academy of Sciences, BioCeV, Praha, Czech Republic
| | - Bruno Rizzuti
- CNR-NANOTEC, SS Rende (CS), Department of Physics, University of Calabria, Rende, Italy.,Instituto de Biocomputación y Física de los Sistemas Complejos (BIFI), Zaragoza, Spain
| | - Pavla Vankova
- Institute of Biotechnology of the Czech Academy of Sciences, BioCeV, Vestec, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jose L Neira
- Instituto de Biocomputación y Física de los Sistemas Complejos (BIFI), Zaragoza, Spain.,Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Spain
| | - Daniel Kavan
- Institute of Microbiology of the Czech Academy of Sciences, BioCeV, Praha, Czech Republic
| | - Noel Mesa-Torres
- Departamento de Química Física, Facultad de Ciencias, Universidad de Granada, Spain
| | - Rita Guzzi
- CNR-NANOTEC, SS Rende (CS), Department of Physics, University of Calabria, Rende, Italy.,Molecular Biophysics Laboratory, Department of Physics, University of Calabria, Rende, Italy
| | - Petr Man
- Institute of Microbiology of the Czech Academy of Sciences, BioCeV, Praha, Czech Republic
| | - Angel L Pey
- Departamento de Química Física, Unidad de Excelencia de Química aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Spain
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11
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Morgan GJ. Transient disorder along pathways to amyloid. Biophys Chem 2021; 281:106711. [PMID: 34839162 DOI: 10.1016/j.bpc.2021.106711] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/15/2023]
Abstract
High-resolution structures of amyloid fibrils formed from normally-folded proteins have revealed non-native conformations of the polypeptide chains. Attaining these conformations apparently requires transition from the native state via a highly disordered conformation, in contrast to earlier models that posited a role for assembly of partially folded proteins. Modifications or interactions that extend the lifetime or constrain the conformations of these disordered states could act to enhance or suppress amyloid formation. Understanding how the properties of both the folded and transiently disordered structural ensembles influence the process of amyloid formation is a substantial challenge, but research into the properties of intrinsically disordered proteins will deliver important insights.
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Affiliation(s)
- Gareth J Morgan
- The Amyloidosis Center and Section of Hematology and Medical Oncology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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12
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Morgan GJ, Buxbaum JN, Kelly JW. Light Chain Stabilization: A Therapeutic Approach to Ameliorate AL Amyloidosis. HEMATO 2021; 2:645-659. [PMID: 35757512 PMCID: PMC9218996 DOI: 10.3390/hemato2040042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Non-native immunoglobulin light chain conformations, including aggregates, appear to cause light chain amyloidosis pathology. Despite significant progress in pharmacological eradication of the neoplastic plasma cells that secrete these light chains, in many patients impaired organ function remains. The impairment is apparently due to a subset of resistant plasma cells that continue to secrete misfolding-prone light chains. These light chains are susceptible to the proteolytic cleavage that may enable light chain aggregation. We propose that small molecules that preferentially bind to the natively folded state of full-length light chains could act as pharmacological kinetic stabilizers, protecting light chains against unfolding, proteolysis and aggregation. Although the sequence of the pathological light chain is unique to each patient, fortunately light chains have highly conserved residues that form binding sites for small molecule kinetic stabilizers. We envision that such stabilizers could complement existing and emerging therapies to benefit light chain amyloidosis patients.
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Affiliation(s)
- Gareth J. Morgan
- Section of Hematology and Medical Oncology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- The Amyloidosis Center, Boston University School of Medicine, Boston, MA 02118, USA
- Correspondence:
| | - Joel N. Buxbaum
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffery W. Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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13
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Pacheco-Garcia JL, Anoz-Carbonell E, Vankova P, Kannan A, Palomino-Morales R, Mesa-Torres N, Salido E, Man P, Medina M, Naganathan AN, Pey AL. Structural basis of the pleiotropic and specific phenotypic consequences of missense mutations in the multifunctional NAD(P)H:quinone oxidoreductase 1 and their pharmacological rescue. Redox Biol 2021; 46:102112. [PMID: 34537677 PMCID: PMC8455868 DOI: 10.1016/j.redox.2021.102112] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/21/2021] [Accepted: 08/17/2021] [Indexed: 10/31/2022] Open
Abstract
The multifunctional nature of human flavoproteins is critically linked to their ability to populate multiple conformational states. Ligand binding, post-translational modifications and disease-associated mutations can reshape this functional landscape, although the structure-function relationships of these effects are not well understood. Herein, we characterized the structural and functional consequences of two mutations (the cancer-associated P187S and the phosphomimetic S82D) on different ligation states which are relevant to flavin binding, intracellular stability and catalysis of the disease-associated NQO1 flavoprotein. We found that these mutations affected the stability locally and their effects propagated differently through the protein structure depending both on the nature of the mutation and the ligand bound, showing directional preference from the mutated site and leading to specific phenotypic manifestations in different functional traits (FAD binding, catalysis and inhibition, intracellular stability and pharmacological response to ligands). Our study thus supports that pleitropic effects of disease-causing mutations and phosphorylation events on human flavoproteins may be caused by long-range structural propagation of stability effects to different functional sites that depend on the ligation-state and site-specific perturbations. Our approach can be of general application to investigate these pleiotropic effects at the flavoproteome scale in the absence of high-resolution structural models.
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Affiliation(s)
- Juan Luis Pacheco-Garcia
- Departamento de Química Física, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain
| | - Ernesto Anoz-Carbonell
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and Joint Unit), Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Pavla Vankova
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030/8, Prague 2, 128 43, Czech Republic
| | - Adithi Kannan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras (IITM), Chennai, 600036, India
| | - Rogelio Palomino-Morales
- Departmento de Bioquímica y Biología Molecular I, Facultad de Ciencias y Centro de Investigaciones Biomédicas (CIBM), Universidad de Granada, Granada, Spain
| | - Noel Mesa-Torres
- Departamento de Química Física, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain
| | - Eduardo Salido
- Center for Rare Diseases (CIBERER), Hospital Universitario de Canarias, Universidad de la Laguna, 38320, Tenerife, Spain
| | - Petr Man
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and Joint Unit), Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras (IITM), Chennai, 600036, India
| | - Angel L Pey
- Departamento de Química Física, Unidad de Excelencia en Química Aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Universidad de Granada, Av. Fuentenueva s/n, 18071, Granada, Spain.
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14
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Markin CJ, Mokhtari DA, Sunden F, Appel MJ, Akiva E, Longwell SA, Sabatti C, Herschlag D, Fordyce PM. Revealing enzyme functional architecture via high-throughput microfluidic enzyme kinetics. Science 2021; 373:373/6553/eabf8761. [PMID: 34437092 DOI: 10.1126/science.abf8761] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 05/24/2021] [Indexed: 12/21/2022]
Abstract
Systematic and extensive investigation of enzymes is needed to understand their extraordinary efficiency and meet current challenges in medicine and engineering. We present HT-MEK (High-Throughput Microfluidic Enzyme Kinetics), a microfluidic platform for high-throughput expression, purification, and characterization of more than 1500 enzyme variants per experiment. For 1036 mutants of the alkaline phosphatase PafA (phosphate-irrepressible alkaline phosphatase of Flavobacterium), we performed more than 670,000 reactions and determined more than 5000 kinetic and physical constants for multiple substrates and inhibitors. We uncovered extensive kinetic partitioning to a misfolded state and isolated catalytic effects, revealing spatially contiguous regions of residues linked to particular aspects of function. Regions included active-site proximal residues but extended to the enzyme surface, providing a map of underlying architecture not possible to derive from existing approaches. HT-MEK has applications that range from understanding molecular mechanisms to medicine, engineering, and design.
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Affiliation(s)
- C J Markin
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | - D A Mokhtari
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | - F Sunden
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | - M J Appel
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | - E Akiva
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
| | - S A Longwell
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - C Sabatti
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94305, USA.,Department of Statistics, Stanford University, Stanford, CA 94305, USA
| | - D Herschlag
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA. .,Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.,ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - P M Fordyce
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA. .,ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.,Department of Genetics, Stanford University, Stanford, CA 94305, USA.,Chan Zuckerberg Biohub; San Francisco, CA 94110, USA
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15
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Sivaraman T, Richa T. Cryptic intermediates and metastable states of proteins as predicted by OneG computational method. J Biomol Struct Dyn 2021; 40:7899-7914. [PMID: 33764262 DOI: 10.1080/07391102.2021.1904288] [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: 10/21/2022]
Abstract
Understanding structural excursions of proteins under folding conditions is crucial to map energy landscapes of proteins. In the present study, OneG computational tool has been used for analyzing possible existence of cryptic intermediates and metastable states of 26 proteins for which three prerequisite inputs of the OneG such as atomic coordinates of proteins, free energy of unfolding (ΔGU) and free energy of exchange (ΔGHX) determined in the absence of denaturant were available during the course of the study. The veraciousness of the tool on predicting the partially folded states of the proteins has been comprehensively described using experimental data available for 15 of the 26 proteins. Meanwhile, possible existence of partially structured states in the folding pathways of 11 other proteins has also been delineated as predicted by the OneG. In addition to mapping the folding pathways of proteins, the salient merits of the tool on systematically addressing the discrepancy between the ΔGU and the ΔGHX of the proteins have also been dealt.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Thirunavukkarasu Sivaraman
- Drug Design and Discovery Lab, Department of Biotechnology, Karpagam Academy of Higher Education (Deemed to be University), Coimbatore, Tamil Nadu, India
| | - Tambi Richa
- Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, UAE
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16
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Mechanistic basis for ubiquitin modulation of a protein energy landscape. Proc Natl Acad Sci U S A 2021; 118:2025126118. [PMID: 33723075 DOI: 10.1073/pnas.2025126118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ubiquitin is a common posttranslational modification canonically associated with targeting proteins to the 26S proteasome for degradation and also plays a role in numerous other nondegradative cellular processes. Ubiquitination at certain sites destabilizes the substrate protein, with consequences for proteasomal processing, while ubiquitination at other sites has little energetic effect. How this site specificity-and, by extension, the myriad effects of ubiquitination on substrate proteins-arises remains unknown. Here, we systematically characterize the atomic-level effects of ubiquitination at various sites on a model protein, barstar, using a combination of NMR, hydrogen-deuterium exchange mass spectrometry, and molecular dynamics simulation. We find that, regardless of the site of modification, ubiquitination does not induce large structural rearrangements in the substrate. Destabilizing modifications, however, increase fluctuations from the native state resulting in exposure of the substrate's C terminus. Both of the sites occur in regions of barstar with relatively high conformational flexibility. Nevertheless, destabilization appears to occur through different thermodynamic mechanisms, involving a reduction in entropy in one case and a loss in enthalpy in another. By contrast, ubiquitination at a nondestabilizing site protects the substrate C terminus through intermittent formation of a structural motif with the last three residues of ubiquitin. Thus, the biophysical effects of ubiquitination at a given site depend greatly on local context. Taken together, our results reveal how a single posttranslational modification can generate a broad array of distinct effects, providing a framework to guide the design of proteins and therapeutics with desired degradation and quality control properties.
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17
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Dai L, Li Z, Chen D, Jia L, Guo J, Zhao T, Nordlund P. Target identification and validation of natural products with label-free methodology: A critical review from 2005 to 2020. Pharmacol Ther 2020; 216:107690. [PMID: 32980441 DOI: 10.1016/j.pharmthera.2020.107690] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 02/08/2023]
Abstract
Natural products (NPs) have been an important source of therapeutic drugs in clinic use and contributed many chemical probes for research. The usefulness of NPs is however often marred by the incomplete understanding of their direct cellular targets. A number of experimental methods for drug target identification have been developed over the years. One class of methods, termed "label-free" methodology, exploits the energetic and biophysical features accompanying the association of macromolecules with drugs and other compounds in their native forms. Herein we review the working principles, assay implementations, and key applications of the most important approaches, and also give examples where they have been applied to NPs. We also assess the key advantages and limitations of each method. Furthermore, we address when and how the label-free methodology can be particularly useful considering some of the unique features of NP chemistry and bioactivation.
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Affiliation(s)
- Lingyun Dai
- Department of Urology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen Urology Minimally Invasive Engineering Center, Shenzhen 518020, Guangdong, China; Department of Geriatrics, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen 518020, Guangdong, China; Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore.
| | - Zhijie Li
- Department of Urology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen Urology Minimally Invasive Engineering Center, Shenzhen 518020, Guangdong, China; Department of Geriatrics, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen 518020, Guangdong, China
| | - Dan Chen
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore
| | - Lin Jia
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong 999077, China
| | - Jinan Guo
- Department of Urology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen Urology Minimally Invasive Engineering Center, Shenzhen 518020, Guangdong, China
| | - Tianyun Zhao
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore
| | - Pär Nordlund
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673, Singapore; Department of Oncology and Pathology, Karolinska Institutet, 171 77 Stockholm, Sweden.
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18
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Site-specific ubiquitination affects protein energetics and proteasomal degradation. Nat Chem Biol 2020; 16:866-875. [PMID: 32483380 DOI: 10.1038/s41589-020-0556-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/05/2020] [Accepted: 04/26/2020] [Indexed: 11/09/2022]
Abstract
Changes in the cellular environment modulate protein energy landscapes to drive important biology, with consequences for signaling, allostery and other vital processes. The effects of ubiquitination are particularly important because of their potential influence on degradation by the 26S proteasome. Moreover, proteasomal engagement requires unstructured initiation regions that many known proteasome substrates lack. To assess the energetic effects of ubiquitination and how these manifest at the proteasome, we developed a generalizable strategy to produce isopeptide-linked ubiquitin within structured regions of a protein. The effects on the energy landscape vary from negligible to dramatic, depending on the protein and site of ubiquitination. Ubiquitination at sensitive sites destabilizes the native structure and increases the rate of proteasomal degradation. In well-folded proteins, ubiquitination can even induce the requisite unstructured regions needed for proteasomal engagement. Our results indicate a biophysical role of site-specific ubiquitination as a potential regulatory mechanism for energy-dependent substrate degradation.
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19
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Novel Apoptotic Mediators Identified by Conservation of Vertebrate Caspase Targets. Biomolecules 2020; 10:biom10040612. [PMID: 32326640 PMCID: PMC7225963 DOI: 10.3390/biom10040612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/08/2020] [Accepted: 04/13/2020] [Indexed: 12/27/2022] Open
Abstract
Caspases are proteases conserved throughout Metazoans and responsible for initiating and executing the apoptotic program. Currently, there are over 1800 known apoptotic caspase substrates, many of them known regulators of cell proliferation and death, which makes them attractive therapeutic targets. However, most caspase substrates are by-standers, and identifying novel apoptotic mediators amongst all caspase substrates remains an unmet need. Here, we conducted an in silico search for significant apoptotic caspase targets across different species within the Vertebrata subphylum, using different criteria of conservation combined with structural features of cleavage sites. We observed that P1 aspartate is highly conserved while the cleavage sites are extensively variable and found that cleavage sites are located primarily in coiled regions composed of hydrophilic amino acids. Using the combination of these criteria, we determined the final list of the 107 most relevant caspase substrates including 30 novel targets previously unknown for their role in apoptosis and cancer. These newly identified substrates can be potential regulators of apoptosis and candidates for anti-tumor therapy.
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20
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Lin X, Gao L, Wang J, Chen X. Sensitive discrimination of glycoproteins and cell differentiation with an array sensing platform exploiting pyrene-derived amphiphile/surfactant assemblies. Chem Commun (Camb) 2019; 55:13673-13676. [PMID: 31647081 DOI: 10.1039/c9cc07515a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An array sensing platform exploiting phenyl boronic acid-functionalized pyrene amphiphile/surfactant assemblies is constructed for glycoprotein discrimination, achieving a discrimination sensitivity of 50 nM. Gastric cancer cell lines of various differentiation grades are successfully discriminated, demonstrating its great potential in sensitive differentiation of glycoprotein-related samples in biomedical diagnosis.
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Affiliation(s)
- Xin Lin
- Research Center for Analytical Sciences, Department of Chemistry, Northeastern University, Box 332, Shenyang 110819, China.
| | - Lifang Gao
- Research Center for Analytical Sciences, Department of Chemistry, Northeastern University, Box 332, Shenyang 110819, China.
| | - Jianhua Wang
- Research Center for Analytical Sciences, Department of Chemistry, Northeastern University, Box 332, Shenyang 110819, China.
| | - Xuwei Chen
- Research Center for Analytical Sciences, Department of Chemistry, Northeastern University, Box 332, Shenyang 110819, China.
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21
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Evidence for the Misfolding of the A1 Domain within Multimeric von Willebrand Factor in Type 2 von Willebrand Disease. J Mol Biol 2019; 432:305-323. [PMID: 31628947 PMCID: PMC7028320 DOI: 10.1016/j.jmb.2019.09.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/13/2019] [Accepted: 09/24/2019] [Indexed: 12/25/2022]
Abstract
Von Willebrand factor (VWF), an exceptionally large multimeric plasma glycoprotein, functions to initiate coagulation by agglutinating platelets in the blood stream to sites of vascular injury. This primary hemostatic function is perturbed in type 2 dysfunctional subtypes of von Willebrand disease (VWD) by mutations that alter the structure and function of the platelet GPIbα adhesive VWF A1 domains. The resulting amino acid substitutions cause local disorder and misfold the native structure of the isolated platelet GPIbα-adhesive A1 domain of VWF in both gain-of-function (type 2B) and loss-of-function (type 2M) phenotypes. These structural effects have not been explicitly observed in A1 domains of VWF multimers native to blood plasma. New mass spectrometry strategies are applied to resolve the structural effects of 2B and 2M mutations in VWF to verify the presence of A1 domain structural disorder in multimeric VWF harboring type 2 VWD mutations. Limited trypsinolysis mass spectrometry (LTMS) and hydrogen-deuterium exchange mass spectrometry (HXMS) are applied to wild-type and VWD variants of the single A1, A2, and A3 domains, an A1A2A3 tridomain fragment of VWF, plasmin-cleaved dimers of VWF, multimeric recombinant VWF, and normal VWF plasma concentrates. Comparatively, these methods show that mutations known to misfold the isolated A1 domain increase the rate of trypsinolysis and the extent of hydrogen-deuterium exchange in local secondary structures of A1 within multimeric VWF. VWD mutation effects are localized to the A1 domain without appreciably affecting the structure and dynamics of other VWF domains. The intrinsic dynamics of A1 observed in recombinant fragments of VWF are conserved in plasma-derived VWF. These studies reveal that structural disorder does occur in VWD variants of the A1 domain within multimeric VWF and provides strong support for VWF misfolding as a result of some, but not all, type 2 VWD variants.
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22
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Giannini E, González LJ, Vila AJ. A simple protocol to characterize bacterial cell-envelope lipoproteins in a native-like environment. Protein Sci 2019; 28:2004-2010. [PMID: 31518027 DOI: 10.1002/pro.3728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 01/04/2023]
Abstract
Physiological conditions in living cells are strictly regulated to allow, optimize, and coordinate biological processes. The bacterial cell envelope is the compartment where the communication with the external environment takes place. This involves membrane proteins, key players in many biological processes that ensure bacterial survival. The biochemical characterization of membrane proteins, either integral, lipidated or peripheral is challenging due to their mixed protein-lipid nature, making it difficult to purify and obtain considerable amounts of samples. In contrast to integral membrane proteins, lipidated proteins are usually purified as truncated soluble versions, neglecting the impact of the membrane environment. Here we report a simple and robust protocol to characterize bacterial lipidated proteins in spheroplasts from Escherichia coli using a β-lactamase as a model. The Metallo-β-lactamase NDM-1 is an enzyme anchored to the inner leaflet of the outer membrane of Gram-negative bacteria. Kinetic parameters and stability of the lipidated NDM-1 and the soluble unbound version (NDM-1 C26A) were measured in spheroplasts and periplasm, respectively. These studies revealed that membrane anchoring increases the KM of the enzyme, consequently decreasing the catalytic efficiency, while not affecting its kinetic stability. This approach can be used to characterize lipidated proteins avoiding the purification step while mimicking its native environment. This approach also helps in filling the gap between in vitro and in vivo studies.
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Affiliation(s)
- Estefanía Giannini
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
| | - Lisandro J González
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.,Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Alejandro J Vila
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.,Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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23
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Marinko J, Huang H, Penn WD, Capra JA, Schlebach JP, Sanders CR. Folding and Misfolding of Human Membrane Proteins in Health and Disease: From Single Molecules to Cellular Proteostasis. Chem Rev 2019; 119:5537-5606. [PMID: 30608666 PMCID: PMC6506414 DOI: 10.1021/acs.chemrev.8b00532] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Advances over the past 25 years have revealed much about how the structural properties of membranes and associated proteins are linked to the thermodynamics and kinetics of membrane protein (MP) folding. At the same time biochemical progress has outlined how cellular proteostasis networks mediate MP folding and manage misfolding in the cell. When combined with results from genomic sequencing, these studies have established paradigms for how MP folding and misfolding are linked to the molecular etiologies of a variety of diseases. This emerging framework has paved the way for the development of a new class of small molecule "pharmacological chaperones" that bind to and stabilize misfolded MP variants, some of which are now in clinical use. In this review, we comprehensively outline current perspectives on the folding and misfolding of integral MPs as well as the mechanisms of cellular MP quality control. Based on these perspectives, we highlight new opportunities for innovations that bridge our molecular understanding of the energetics of MP folding with the nuanced complexity of biological systems. Given the many linkages between MP misfolding and human disease, we also examine some of the exciting opportunities to leverage these advances to address emerging challenges in the development of therapeutics and precision medicine.
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Affiliation(s)
- Justin
T. Marinko
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Hui Huang
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Wesley D. Penn
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - John A. Capra
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37245, United States
| | - Jonathan P. Schlebach
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Charles R. Sanders
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
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24
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Thibeault J, Patrick J, Martin A, Ortiz-Perez B, Hill S, Zhang S, Xia K, Colón W. Sarkosyl: A milder detergent than SDS for identifying proteins with moderately high hyperstability using gel electrophoresis. Anal Biochem 2019; 571:21-24. [PMID: 30779907 DOI: 10.1016/j.ab.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
Sodium dodecyl sulfate (SDS) is a detergent used as a strong denaturant of proteins in gel electrophoresis. It has previously been shown that certain hyperstable, also known as kinetically stable, proteins are resistant to SDS and thus require heating for their denaturation in the presence of SDS. Because of its high denaturing strength, relatively few proteins are resistant to SDS thereby limiting the current use of SDS-PAGE for identifying hyperstable degradation-resistant proteins. In this study, we show that sarkosyl, a milder detergent than SDS, is able to identify proteins with moderately high kinetic stability that lack SDS-resistance. Our assay involves running and subsequently comparing boiled and unheated protein samples containing sarkosyl, instead of SDS, on PAGE gels and identifying subsequent differences in protein migration. Our results also show that sarkosyl and SDS may be combined in PAGE experiments at varying relative percentages to obtain semi-quantitative information about a protein's kinetic stability in a range inaccessible by probing through native- or SDS-PAGE. Using protein extracts from various legumes as model systems, we detected proteins with a range of protein stability from nearly SDS-resistant to barely sarkosyl resistant.
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Affiliation(s)
- Jane Thibeault
- Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Jessica Patrick
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Alexi Martin
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Brian Ortiz-Perez
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Shakeema Hill
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Songjie Zhang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Ke Xia
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Wilfredo Colón
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
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25
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Brown MC, Abdine A, Chavez J, Schaffner A, Torres-Arancivia C, Lada B, JiJi RD, Osman R, Cooley JW, Ubarretxena-Belandia I. Unwinding of the Substrate Transmembrane Helix in Intramembrane Proteolysis. Biophys J 2019; 114:1579-1589. [PMID: 29642028 DOI: 10.1016/j.bpj.2018.01.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/19/2017] [Accepted: 01/08/2018] [Indexed: 10/17/2022] Open
Abstract
Intramembrane-cleaving proteases (I-CLiPs) activate pools of single-pass helical membrane protein signaling precursors that are key in the physiology of prokaryotic and eukaryotic cells. Proteases typically cleave peptide bonds within extended or flexible regions of their substrates, and thus the mechanism underlying the ability of I-CLiPs to hydrolyze the presumably α-helical transmembrane domain (TMD) of these membrane proteins is unclear. Using deep-ultraviolet resonance Raman spectroscopy in combination with isotopic labeling, we show that although predominantly in canonical α-helical conformation, the TMD of the established I-CLiP substrate Gurken displays 310-helical geometry. As measured by microscale thermophoresis, this substrate binds with high affinity to the I-CLiPs GlpG rhomboid and MCMJR1 presenilin homolog in detergent micelles. Binding results in deep-ultraviolet resonance Raman spectra, indicating conformational changes consistent with unwinding of the 310-helical region of the substrate's TMD. This 310-helical conformation is key for intramembrane proteolysis, as the substitution of a single proline residue in the TMD of Gurken by alanine suppresses 310-helical content in favor of α-helical geometry and abolishes cleavage without affecting binding to the I-CLiP. Complemented by molecular dynamics simulations of the TMD of Gurken, our vibrational spectroscopy data provide biophysical evidence in support of a model in which the transmembrane region of cleavable I-CLiP substrates displays local deviations in canonical α-helical conformation characterized by chain flexibility, and binding to the enzyme results in conformational changes that facilitate local unwinding of the transmembrane helix for cleavage.
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Affiliation(s)
- Mia C Brown
- Department of Chemistry, University of Missouri, Columbia, Missouri
| | - Alaa Abdine
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jose Chavez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Adam Schaffner
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Celia Torres-Arancivia
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Brian Lada
- Department of Chemistry, University of Missouri, Columbia, Missouri
| | - Renee D JiJi
- Department of Chemistry, University of Missouri, Columbia, Missouri
| | - Roman Osman
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jason W Cooley
- Department of Chemistry, University of Missouri, Columbia, Missouri.
| | - Iban Ubarretxena-Belandia
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York; Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, Leioa, Spain.
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26
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Whittington AC, Mason AJ, Rokyta DR. A Single Mutation Unlocks Cascading Exaptations in the Origin of a Potent Pitviper Neurotoxin. Mol Biol Evol 2019; 35:887-898. [PMID: 29329419 DOI: 10.1093/molbev/msx334] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Evolutionary innovations and complex phenotypes seemingly require an improbable amount of genetic change to evolve. Rattlesnakes display two dramatically different venom phenotypes. Type I venoms are hemorrhagic with low systemic toxicity and high expression of tissue-destroying snake venom metalloproteinases. Type II venoms are highly neurotoxic and lack snake venom metalloproteinase expression and associated hemorrhagic activity. This dichotomy hinges on Mojave toxin (MTx), a phospholipase A2 (PLA2) based β-neurotoxin expressed in Type II venoms. MTx is comprised of a nontoxic acidic subunit that undergoes extensive proteolytic processing and allosterically regulates activity of a neurotoxic basic subunit. Evolution of the acidic subunit presents an evolutionary challenge because the need for high expression of a nontoxic venom component and the proteolytic machinery required for processing suggests genetic changes of seemingly little immediate benefit to fitness. We showed that MTx evolved through a cascading series of exaptations unlocked by a single nucleotide change. The evolution of one new cleavage site in the acidic subunit unmasked buried cleavage sites already present in ancestral PLA2s, enabling proteolytic processing. Snake venom serine proteases, already present in the venom to disrupt prey hemostasis, possess the requisite specificities for MTx acidic subunit proteolysis. The dimerization interface between MTx subunits evolved by exploiting a latent, but masked, hydrophobic interaction between ancestral PLA2s. The evolution of MTx through exaptation of existing functional and structural features suggests complex phenotypes that depend on evolutionary innovations can arise from minimal genetic change enabled by prior evolution.
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Affiliation(s)
- A Carl Whittington
- Department of Biological Science, Florida State University, Tallahassee, FL
| | - Andrew J Mason
- Department of Biology, University of Central Florida, Orlando, FL
- Department of Biological Sciences, Clemson University, Clemson, SC
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL
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27
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Kirkness MWH, Forde NR. Single-Molecule Assay for Proteolytic Susceptibility: Force-Induced Collagen Destabilization. Biophys J 2019; 114:570-576. [PMID: 29414702 DOI: 10.1016/j.bpj.2017.12.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/01/2017] [Accepted: 12/11/2017] [Indexed: 01/07/2023] Open
Abstract
Force plays a key role in regulating dynamics of biomolecular structure and interactions, yet techniques are lacking to manipulate and continuously read out this response with high throughput. We present an enzymatic assay for force-dependent accessibility of structure that makes use of a wireless mini-radio centrifuge force microscope to provide a real-time readout of kinetics. The microscope is designed for ease of use, fits in a standard centrifuge bucket, and offers high-throughput, video-rate readout of individual proteolytic cleavage events. Proteolysis measurements on thousands of tethered collagen molecules show a load-enhanced trypsin sensitivity, indicating destabilization of the triple helix.
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Affiliation(s)
- Michael W H Kirkness
- Department of Molecular Biology and Biochemistry, Burnaby, British Columbia, Canada
| | - Nancy R Forde
- Department of Molecular Biology and Biochemistry, Burnaby, British Columbia, Canada; Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada.
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28
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Iyer LK, Phanse R, Xu M, Lan W, Krause ME, Bolgar M, Hart S. Pulse Proteolysis: An Orthogonal Tool for Protein Formulation Screening. J Pharm Sci 2019; 108:842-850. [DOI: 10.1016/j.xphs.2018.09.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 08/24/2018] [Accepted: 09/17/2018] [Indexed: 12/24/2022]
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29
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Moss DL, Park HW, Mettu RR, Landry SJ. Deimmunizing substitutions in Pseudomonas exotoxin domain III perturb antigen processing without eliminating T-cell epitopes. J Biol Chem 2019; 294:4667-4681. [PMID: 30683694 DOI: 10.1074/jbc.ra118.006704] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/23/2019] [Indexed: 11/06/2022] Open
Abstract
Effective adaptive immune responses depend on activation of CD4+ T cells via the presentation of antigen peptides in the context of major histocompatibility complex (MHC) class II. The structure of an antigen strongly influences its processing within the endolysosome and potentially controls the identity of peptides that are presented to T cells. A recombinant immunotoxin, comprising exotoxin A domain III (PE-III) from Pseudomonas aeruginosa and a cancer-specific antibody fragment, has been developed to manage cancer, but its effectiveness is limited by the induction of neutralizing antibodies. Here, we observed that this immunogenicity is substantially reduced by substituting six residues within PE-III. Although these substitutions targeted T-cell epitopes, we demonstrate that reduced conformational stability and protease resistance were responsible for the reduced antibody titer. Analysis of mouse T-cell responses coupled with biophysical studies on single-substitution versions of PE-III suggested that modest but comprehensible changes in T-cell priming can dramatically perturb antibody production. The most strongly responsive PE-III epitope was well-predicted by a structure-based algorithm. In summary, single-residue substitutions can drastically alter the processing and immunogenicity of PE-III but have only modest effects on CD4+ T-cell priming in mice. Our findings highlight the importance of structure-based processing constraints for accurate epitope prediction.
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Affiliation(s)
- Daniel L Moss
- From the Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112 and
| | - Hee-Won Park
- From the Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112 and
| | - Ramgopal R Mettu
- the Department of Computer Science, Tulane University, New Orleans, Louisiana 70118
| | - Samuel J Landry
- From the Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112 and
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30
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Rosemond SN, Hamadani KM, Cate JHD, Marqusee S. Modulating long-range energetics via helix stabilization: A case study using T4 lysozyme. Protein Sci 2018; 27:2084-2093. [PMID: 30284332 DOI: 10.1002/pro.3521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 11/07/2022]
Abstract
Cooperative protein folding requires distant regions of a protein to interact and provide mutual stabilization. The mechanism of this long-distance coupling remains poorly understood. Here, we use T4 lysozyme (T4L*) as a model to investigate long-range communications across two subdomains of a globular protein. T4L* is composed of two structurally distinct subdomains, although it behaves in a two-state manner at equilibrium. The subdomains of T4L* are connected via two topological connections: the N-terminal helix that is structurally part of the C-terminal subdomain (the A-helix) and a long helix that spans both subdomains (the C-helix). To understand the role that the C-helix plays in cooperative folding, we analyzed a circularly permuted version of T4L* (CP13*), whose subdomains are connected only by the C-helix. We demonstrate that when isolated as individual fragments, both subdomains of CP13* can fold autonomously into marginally stable conformations. The energetics of the N-terminal subdomain depend on the formation of a salt bridge known to be important for stability in the full-length protein. We show that the energetic contribution of the salt bridge to the stability of the N-terminal fragment increases when the C-helix is stabilized, such as occurs upon folding of the C-terminal subdomain. These results suggest a model where long-range energetic coupling is mediated by helix stabilization and not specific tertiary interactions.
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Affiliation(s)
- Sabriya N Rosemond
- California Institute for Quantitative Biosciences, University of California, Berkeley, California, 94720.,Department of Molecular and Cell Biology, University of California, Berkeley, California, 94720-3220
| | - Kambiz M Hamadani
- California Institute for Quantitative Biosciences, University of California, Berkeley, California, 94720.,California State University San Marcos, San Marcos, California, 92096
| | - Jamie H D Cate
- California Institute for Quantitative Biosciences, University of California, Berkeley, California, 94720.,Department of Molecular and Cell Biology, University of California, Berkeley, California, 94720-3220.,Department of Chemistry, University of California, Berkeley, California, 94720
| | - Susan Marqusee
- California Institute for Quantitative Biosciences, University of California, Berkeley, California, 94720.,Department of Molecular and Cell Biology, University of California, Berkeley, California, 94720-3220.,Department of Chemistry, University of California, Berkeley, California, 94720.,Chan Zuckerberg Biohub, San Francisco, CA, 94158
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31
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James JK, Pike DH, Khan IJ, Nanda V. Structural and Dynamic Properties of Allergen and Non-Allergen Forms of Tropomyosin. Structure 2018; 26:997-1006.e5. [PMID: 29887498 PMCID: PMC6697176 DOI: 10.1016/j.str.2018.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/28/2018] [Accepted: 05/08/2018] [Indexed: 11/26/2022]
Abstract
To what extent do structural and biophysical features of food allergen proteins distinguish them from other proteins in our diet? Invertebrate tropomyosins (Tpms) as a class are considered "pan-allergens," inducing food allergy to shellfish and respiratory allergy to dust mites. Vertebrate Tpms are not known to elicit allergy or cross-reactivity, despite their high structural similarity and sequence identity to invertebrate homologs. We expect allergens are sufficiently stable against gastrointestinal proteases to survive for immune sensitization in the intestines, and that proteolytic stability will correlate with thermodynamic stability. Thermal denaturation of shrimp Tpm shows that it is more stable than non-allergen vertebrate Tpm. Shrimp Tpm is also more resistant to digestion. Molecular dynamics uncover local dynamics that select epitopes and global differences in flexibility between shrimp and pig Tpm that discriminate allergens from non-allergens. Molecular determinants of allergenicity depend not only on sequence but on contributions of protein structure and dynamics.
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Affiliation(s)
- Jose K James
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Douglas H Pike
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - I John Khan
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Vikas Nanda
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
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32
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Rossi F, Morrone C, Massarotti A, Ferraris DM, Valenti A, Perugino G, Miggiano R. Crystal structure of a thermophilic O6-alkylguanine-DNA alkyltransferase-derived self-labeling protein-tag in covalent complex with a fluorescent probe. Biochem Biophys Res Commun 2018; 500:698-703. [DOI: 10.1016/j.bbrc.2018.04.139] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 04/17/2018] [Indexed: 02/07/2023]
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33
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Conformational Stability of the Hemagglutinin of H5N1 Influenza A Viruses Influences Susceptibility to Broadly Neutralizing Stem Antibodies. J Virol 2018; 92:JVI.00247-18. [PMID: 29593038 PMCID: PMC5974491 DOI: 10.1128/jvi.00247-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 03/14/2018] [Indexed: 12/29/2022] Open
Abstract
Vaccines that elicit broadly neutralizing antibodies to the conserved stem of hemagglutinin (HA) are being developed as universal influenza vaccines that protect against influenza across multiple years. However, different influenza virus strains, even those in the same subtype with identical stem sequences, can vary in susceptibility to broadly neutralizing stem antibodies, and the reasons are not understood. Here we studied potential mechanisms underlying the differing sensitivities of a panel of H5N1 HA pseudoviruses to broadly neutralizing stem antibodies. We found that greater HA conformational stability, as measured by thermal inactivation and pH triggering of conformational changes, correlates with reduced neutralization sensitivity and antibody binding to HA under neutral- and low-pH conditions. Our data indicate that the conformational stability of HA is an important attribute of susceptibility to broadly neutralizing stem antibodies and is influenced by residues outside the stem antibody epitopes. IMPORTANCE The influenza virus surface glycoprotein hemagglutinin (HA) mediates virus attachment and membrane fusion between virus and host cells, allowing the viral core to enter the host cell cytoplasm for replication. Fusion occurs when HA undergoes low-pH-induced-conformational changes during endocytosis. Broadly neutralizing antibodies targeted to the conserved stem region of HA interfere with conformational changes required for fusion. Vaccines that elicit such antibodies are being developed as novel universal influenza vaccines for multiyear protection. We investigated why H5N1 HAs from different strains differ in their sensitivity to broadly neutralizing stem antibodies despite having conserved epitopes. We report that HA conformational stability due to residues outside the antibody binding site accounted for much of the variation in susceptibility to neutralization by stem antibodies. These findings highlight the importance of nonepitope residues in influencing neutralization sensitivity to stem antibodies and the complexities in developing universal vaccines targeting conserved epitopes in the HA stem.
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34
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Colón W, Church J, Sen J, Thibeault J, Trasatti H, Xia K. Biological Roles of Protein Kinetic Stability. Biochemistry 2017; 56:6179-6186. [PMID: 29087706 DOI: 10.1021/acs.biochem.7b00942] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A protein's stability may range from nonexistent, as in the case of intrinsically disordered proteins, to very high, as indicated by a protein's resistance to degradation, even under relatively harsh conditions. The stability of this latter group is usually under kinetic control because of a high activation energy for unfolding that virtually traps the protein in a specific conformation, thereby conferring resistance to proteolytic degradation and misfolding aggregation. The usual outcome of kinetic stability is a longer protein half-life. Thus, the protective role of protein kinetic stability is often appreciated, but relatively little is known about the extent of biological roles related to this property. In this Perspective, we will discuss several known or putative biological roles of protein kinetic stability, including protection from stressors to avoid aggregation or premature degradation, achieving long-term phenotypic change, and regulating cellular processes by controlling the trigger and timing of molecular motion. The picture that emerges from this analysis is that protein kinetic stability is involved in a myriad of known and yet to be discovered biological functions via its ability to confer degradation resistance and control the timing, extent, and permanency of molecular motion.
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Affiliation(s)
- Wilfredo Colón
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jennifer Church
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jayeeta Sen
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jane Thibeault
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Hannah Trasatti
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Ke Xia
- Department of Chemistry and Chemical Biology, ‡Center for Biotechnology and Interdisciplinary Studies, and §Biochemistry and Biophysics Graduate Program, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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35
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Liu F, Fitzgerald MC. Large-Scale Analysis of Breast Cancer-Related Conformational Changes in Proteins Using Limited Proteolysis. J Proteome Res 2016; 15:4666-4674. [PMID: 27794609 DOI: 10.1021/acs.jproteome.6b00755] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conformational changes in proteins can lead to disease. Thus, methods for identifying conformational changes in proteins can further improve our understanding and facilitate detection of disease states. Here we combine limited proteolysis (LiP) with Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) to characterize breast cancer-related conformational changes in proteins on the proteomic scale. Studied here are the conformational properties of proteins in two cell culture models of breast cancer, including the MCF-10A and MCF-7 cell lines. The SILAC-LiP approach described here identified ∼200 proteins with cell-line-dependent conformational changes, as determined by their differential susceptibility to proteolytic digestion using the nonspecific protease, proteinase K. The protease susceptibility profiles of the proteins in these cell lines were compared to thermodynamic stability and expression level profiles previously generated for proteins in these same breast cancer cell lines. The comparisons revealed that there was little overlap between the proteins with protease susceptibility changes and the proteins with thermodynamic stability and/or expression level changes. Thus, the large-scale conformational analysis described here provides unique insight into the molecular basis of the breast cancer phenotypes in this study.
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Affiliation(s)
- Fang Liu
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
| | - Michael C Fitzgerald
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
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36
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Xia K, Pittelli S, Church J, Colón W. Kinetic Stability of Proteins in Beans and Peas: Implications for Protein Digestibility, Seed Germination, and Plant Adaptation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:7649-7657. [PMID: 27643830 DOI: 10.1021/acs.jafc.6b01965] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Kinetically stable proteins (KSPs) are resistant to the denaturing detergent sodium dodecyl sulfate (SDS). Such resilience makes KSPs resistant to proteolytic degradation and may have arisen in nature as a mechanism for organismal adaptation and survival against harsh conditions. Legumes are well-known for possessing degradation-resistant proteins that often diminish their nutritional value. Here we applied diagonal two-dimensional (D2D) SDS-polyacrylamide gel electrophoresis (PAGE), a method that allows for the proteomics-level identification of KSPs, to a group of 12 legumes (mostly beans and peas) of agricultural and nutritional importance. Our proteomics results show beans that are more difficult to digest, such as soybean, lima beans, and various common beans, have high contents of KSPs. In contrast, mung bean, red lentil, and various peas that are highly digestible contain low amounts of KSPs. Identified proteins with high kinetic stability are associated with warm-season beans, which germinate at higher temperatures. In contrast, peas and red lentil, which are cool-season legumes, contain low levels of KSPs. Thus, our results show protein kinetic stability is an important factor in the digestibility of legume proteins and may relate to nutrition efficiency, timing of seed germination, and legume resistance to biotic stressors. Furthermore, we show D2D SDS-PAGE is a powerful method that could be applied for determining the abundance and identity of KSPs in engineered and wild legumes and for advancing basic research and associated applications.
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Affiliation(s)
- Ke Xia
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Sandy Pittelli
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Jennifer Church
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Wilfredo Colón
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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37
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Morgan GJ, Kelly JW. The Kinetic Stability of a Full-Length Antibody Light Chain Dimer Determines whether Endoproteolysis Can Release Amyloidogenic Variable Domains. J Mol Biol 2016; 428:4280-4297. [PMID: 27569045 DOI: 10.1016/j.jmb.2016.08.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/29/2016] [Accepted: 08/21/2016] [Indexed: 12/17/2022]
Abstract
Light chain (LC) amyloidosis (AL amyloidosis) appears to be caused by the misfolding, or misfolding and aggregation of an antibody LC or fragment thereof and is fatal if untreated. LCs are secreted from clonally expanded plasma cells, generally as disulfide-linked dimers, with each monomer comprising one constant and one variable domain. The energetic contribution of each domain and the role of endoproteolysis in AL amyloidosis remain unclear. To investigate why only some LCs form amyloid and cause organ toxicity, we measured the aggregation propensity and kinetic stability of LC dimers and their associated variable domains from AL amyloidosis patients and non-patients. All the variable domains studied readily form amyloid fibrils, whereas none of the full-length LC dimers, even those from AL amyloidosis patients, are amyloidogenic. Kinetic stability-that is, the free energy difference between the native state and the unfolding transition state-dictates the LC's unfolding rate. Full-length LC dimers derived from AL amyloidosis patients unfold more rapidly than other full-length LC dimers and can be readily cleaved into their component domains by proteases, whereas non-amyloidogenic LC dimers are more kinetically stable and resistant to endoproteolysis. Our data suggest that amyloidogenic LC dimers are kinetically unstable (unfold faster) and are thus susceptible to endoproteolysis that results in the release amyloidogenic LC fragments, whereas other LCs are not as amenable to unfolding and endoproteolysis and are therefore aggregation resistant. Pharmacologic kinetic stabilization of the full-length LC dimer could be a useful strategy to treat AL amyloidosis.
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Affiliation(s)
- Gareth J Morgan
- Departments of Chemistry and Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffery W Kelly
- Departments of Chemistry and Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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38
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Kinetic stability of cystathionine beta-synthase can be modulated by structural analogs of S-adenosylmethionine: Potential approach to pharmacological chaperone therapy for homocystinuria. Biochimie 2016; 126:6-13. [DOI: 10.1016/j.biochi.2016.01.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 01/15/2016] [Indexed: 11/19/2022]
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39
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Trindade RV, Pinto AFM, Santos DS, Bizarro CV. Pulse Proteolysis and Precipitation for Target Identification. J Proteome Res 2016; 15:2236-45. [DOI: 10.1021/acs.jproteome.6b00214] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rogério V. Trindade
- Centro
de Pesquisas em Biologia Molecular e Funcional (CPBMF), Instituto
Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), 6681/92-A. Av. Ipiranga-TECNOPUC-Prédio 92A 90619-900, Porto Alegre, Rio Grande do Sul, Brazil
| | - Antônio F. M. Pinto
- Centro
de Pesquisas em Biologia Molecular e Funcional (CPBMF), Instituto
Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), 6681/92-A. Av. Ipiranga-TECNOPUC-Prédio 92A 90619-900, Porto Alegre, Rio Grande do Sul, Brazil
| | - Diógenes S. Santos
- Centro
de Pesquisas em Biologia Molecular e Funcional (CPBMF), Instituto
Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), 6681/92-A. Av. Ipiranga-TECNOPUC-Prédio 92A 90619-900, Porto Alegre, Rio Grande do Sul, Brazil
| | - Cristiano V. Bizarro
- Centro
de Pesquisas em Biologia Molecular e Funcional (CPBMF), Instituto
Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), 6681/92-A. Av. Ipiranga-TECNOPUC-Prédio 92A 90619-900, Porto Alegre, Rio Grande do Sul, Brazil
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40
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Chen C, Yun JH, Kim JH, Park C. Effect of circular permutations on transient partial unfolding in proteins. Protein Sci 2016; 25:1483-91. [PMID: 27164316 DOI: 10.1002/pro.2945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 05/05/2016] [Accepted: 05/06/2016] [Indexed: 12/22/2022]
Abstract
Under native conditions, proteins can undergo transient partial unfolding, which may cause proteins to misfold or aggregate. A change in sequence connectivity by circular permutation may affect the energetics of transient partial unfolding in proteins without altering the three-dimensional structures. Using Escherichia coli dihydrofolate reductase (DHFR) as a model system, we investigated how circular permutation affects transient partial unfolding in proteins. We constructed three circular permutants, CP18, CP37, and CP87, with the new N-termini at residue 18, 37, and 87, respectively, and probed transient partial unfolding by native-state proteolysis. The new termini in CP18, CP37, and CP87 are within, near, and distal to the Met20 loop, which is known to be dynamic and also part of the region that undergoes transient unfolding in wild-type DHFR. The stabilities of both native and partially unfolded forms of CP18 are similar to those of wild-type DHFR, suggesting that the influence of introducing new termini in a dynamic region to the protein is minimal. CP37 has a significantly more accessible partially unfolded form than wild-type DHFR, demonstrating that introducing new termini near a dynamic region may promote transient partial unfolding. CP87 has significantly destabilized native and partially unfolded forms, confirming that modification of the folded region in a partially unfolded form destabilizes the partially unfolded form similar to the native form. Our findings provide valuable guidelines to control transient partial unfolding in designing circular permutants in proteins.
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Affiliation(s)
- Chen Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, 47907
| | - Jung-Hun Yun
- Faculty of Biotechnology, College of Applied Life Science, SARI, Jeju National University, Jeju-Do, 690-756, Korea
| | - Jae-Hoon Kim
- Faculty of Biotechnology, College of Applied Life Science, SARI, Jeju National University, Jeju-Do, 690-756, Korea
| | - Chiwook Park
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, 47907
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41
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Malhotra P, Udgaonkar JB. Secondary Structural Change Can Occur Diffusely and Not Modularly during Protein Folding and Unfolding Reactions. J Am Chem Soc 2016; 138:5866-78. [DOI: 10.1021/jacs.6b03356] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pooja Malhotra
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B. Udgaonkar
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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42
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Guo R, Gaffney K, Yang Z, Kim M, Sungsuwan S, Huang X, Hubbell WL, Hong H. Steric trapping reveals a cooperativity network in the intramembrane protease GlpG. Nat Chem Biol 2016; 12:353-360. [PMID: 26999782 PMCID: PMC4837050 DOI: 10.1038/nchembio.2048] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 01/22/2016] [Indexed: 12/21/2022]
Abstract
Membrane proteins are assembled through balanced interactions among protein, lipids and water. Studying their folding while maintaining the native lipid environment is necessary but challenging. Here we present methods for analyzing key elements in membrane protein folding including thermodynamic stability, compactness of the unfolded state and folding cooperativity under native conditions. The methods are based on steric trapping which couples unfolding of a doubly-biotinylated protein to binding of monovalent streptavidin (mSA). We further advanced this technology for general application by developing versatile biotin probes possessing spectroscopic reporters that are sensitized by mSA binding or protein unfolding. By applying these methods to an intramembrane protease GlpG of Escherichia coli, we elucidated a widely unraveled unfolded state, subglobal unfolding of the region encompassing the active site, and a network of cooperative and localized interactions to maintain the stability. These findings provide crucial insights into the folding energy landscape of membrane proteins.
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Affiliation(s)
- Ruiqiong Guo
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Kristen Gaffney
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Zhongyu Yang
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Miyeon Kim
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Suttipun Sungsuwan
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Xuefei Huang
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Wayne L Hubbell
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Heedeok Hong
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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43
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Di Bartolo N, Compton ELR, Warne T, Edwards PC, Tate CG, Schertler GFX, Booth PJ. Complete Reversible Refolding of a G-Protein Coupled Receptor on a Solid Support. PLoS One 2016; 11:e0151582. [PMID: 26982879 PMCID: PMC4794186 DOI: 10.1371/journal.pone.0151582] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 03/01/2016] [Indexed: 12/22/2022] Open
Abstract
The factors defining the correct folding and stability of integral membrane proteins are poorly understood. Folding of only a few select membrane proteins has been scrutinised, leaving considerable deficiencies in knowledge for large protein families, such as G protein coupled receptors (GPCRs). Complete reversible folding, which is problematic for any membrane protein, has eluded this dominant receptor family. Moreover, attempts to recover receptors from denatured states are inefficient, yielding at best 40–70% functional protein. We present a method for the reversible unfolding of an archetypal family member, the β1-adrenergic receptor, and attain 100% recovery of the folded, functional state, in terms of ligand binding, compared to receptor which has not been subject to any unfolding and retains its original, folded structure. We exploit refolding on a solid support, which could avoid unwanted interactions and aggregation that occur in bulk solution. We determine the changes in structure and function upon unfolding and refolding. Additionally, we employ a method that is relatively new to membrane protein folding; pulse proteolysis. Complete refolding of β1-adrenergic receptor occurs in n-decyl-β-D-maltoside (DM) micelles from a urea-denatured state, as shown by regain of its original helical structure, ligand binding and protein fluorescence. The successful refolding strategy on a solid support offers a defined method for the controlled refolding and recovery of functional GPCRs and other membrane proteins that suffer from instability and irreversible denaturation once isolated from their native membranes.
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Affiliation(s)
- Natalie Di Bartolo
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
- * E-mail:
| | - Emma L. R. Compton
- Organisational and Staff Development Unit, University of Strathclyde, Glasgow, United Kingdom
| | - Tony Warne
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Patricia C. Edwards
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Christopher G. Tate
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | | | - Paula J. Booth
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
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44
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Hinzman MW, Essex ME, Park C. Salt bridge as a gatekeeper against partial unfolding. Protein Sci 2016; 25:999-1009. [PMID: 26916981 DOI: 10.1002/pro.2908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/23/2016] [Accepted: 02/23/2016] [Indexed: 11/06/2022]
Abstract
Salt bridges are frequently observed in protein structures. Because the energetic contribution of salt bridges is strongly dependent on the environmental context, salt bridges are believed to contribute to the structural specificity rather than the stability. To test the role of salt bridges in enhancing structural specificity, we investigated the contribution of a salt bridge to the energetics of native-state partial unfolding in a cysteine-free version of Escherichia coli ribonuclease H (RNase H*). Thermolysin cleaves a protruding loop of RNase H(*) through transient partial unfolding under native conditions. Lys86 and Asp108 in RNase H(*) form a partially buried salt bridge that tethers the protruding loop. Investigation of the global stability of K86Q/D108N RNase H(*) showed that the salt bridge does not significantly contribute to the global stability. However, K86Q/D108N RNase H(*) is greatly more susceptible to proteolysis by thermolysin than wild-type RNase H(*) is. The free energy for partial unfolding determined by native-state proteolysis indicates that the salt bridge significantly increases the energy for partial unfolding by destabilizing the partially unfolded form. Double mutant cycles with single and double mutations of the salt bridge suggest that the partially unfolded form is destabilized due to a significant decrease in the interaction energy between Lys86 and Asp108 upon partial unfolding. This study demonstrates that, even in the case that a salt bridge does not contribute to the global stability, the salt bridge may function as a gatekeeper against partial unfolding that disturbs the optimal geometry of the salt bridge.
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Affiliation(s)
- Mark W Hinzman
- Department of Medicinal Chemistry and Molecular Pharmacology, Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, 47907
| | - Morgan E Essex
- Department of Medicinal Chemistry and Molecular Pharmacology, Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, 47907
| | - Chiwook Park
- Department of Medicinal Chemistry and Molecular Pharmacology, Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, 47907
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45
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Conformational dynamics is key to understanding loss-of-function of NQO1 cancer-associated polymorphisms and its correction by pharmacological ligands. Sci Rep 2016; 6:20331. [PMID: 26838129 PMCID: PMC4738246 DOI: 10.1038/srep20331] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/30/2015] [Indexed: 12/25/2022] Open
Abstract
Protein dynamics is essential to understand protein function and stability, even though is rarely investigated as the origin of loss-of-function due to genetic variations. Here, we use biochemical, biophysical, cell and computational biology tools to study two loss-of-function and cancer-associated polymorphisms (p.R139W and p.P187S) in human NAD(P)H quinone oxidoreductase 1 (NQO1), a FAD-dependent enzyme which activates cancer pro-drugs and stabilizes several oncosuppressors. We show that p.P187S strongly destabilizes the NQO1 dimer in vitro and increases the flexibility of the C-terminal domain, while a combination of FAD and the inhibitor dicoumarol overcome these alterations. Additionally, changes in global stability due to polymorphisms and ligand binding are linked to the dynamics of the dimer interface, whereas the low activity and affinity for FAD in p.P187S is caused by increased fluctuations at the FAD binding site. Importantly, NQO1 steady-state protein levels in cell cultures correlate primarily with the dynamics of the C-terminal domain, supporting a directional preference in NQO1 proteasomal degradation and the use of ligands binding to this domain to stabilize p.P187S in vivo. In conclusion, protein dynamics are fundamental to understanding loss-of-function in p.P187S, and to develop new pharmacological therapies to rescue this function.
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46
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Fuchs JE, Muñoz IG, Timson DJ, Pey AL. Experimental and computational evidence on conformational fluctuations as a source of catalytic defects in genetic diseases. RSC Adv 2016. [DOI: 10.1039/c6ra05499d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Catalytic mutants causing inherited type III galactosemia alter active site structural dynamics and shift the native conformational equilibrium towards inactive conformations.
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Affiliation(s)
- Julian E. Fuchs
- Institute of General, Inorganic and Theoretical Chemistry
- Faculty of Chemistry and Pharmacy
- University of Innsbruck
- Innsbruck
- Austria
| | - Inés G. Muñoz
- Crystallography and Protein Engineering Unit
- Structural Biology and Biocomputing Programme
- Spanish National Cancer Research Centre (CNIO)
- Madrid
- Spain
| | - David J. Timson
- School of Pharmacy and Biomolecular Sciences
- The University of Brighton
- Brighton
- UK
| | - Angel L. Pey
- Department of Physical Chemistry
- Faculty of Sciences
- University of Granada
- Granada
- Spain
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47
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Bioanalytical approaches to assess the proteolytic stability of therapeutic fusion proteins. Bioanalysis 2015; 7:3035-51. [DOI: 10.4155/bio.15.217] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Therapeutic fusion proteins (TFPs) are designed to improve the therapeutic profile of an endogenous protein or protein fragment with a limited dose frequency providing the desired pharmacological activity in vivo. Fusion of a therapeutic protein to a half-life extension or targeting domain can improve the disposition of the molecule or introduce a novel mechanism of action. Prolonged exposure and altered biodistribution of an endogenous protein through fusion technology increases the potential for local protein unfolding during circulation increasing the chance for partial proteolysis of the therapeutic domain. Characterizing the proteolytic liabilities of a TFP can guide engineering efforts to inhibit or hinder partial proteolysis. This review focuses on considerations and techniques for evaluating the stability of a TFP both in vivo and in vitro.
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48
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Rajabi K, Ashcroft AE, Radford SE. Mass spectrometric methods to analyze the structural organization of macromolecular complexes. Methods 2015; 89:13-21. [DOI: 10.1016/j.ymeth.2015.03.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/25/2015] [Accepted: 03/06/2015] [Indexed: 01/14/2023] Open
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49
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Selzer L, Kant R, Wang JCY, Bothner B, Zlotnick A. Hepatitis B Virus Core Protein Phosphorylation Sites Affect Capsid Stability and Transient Exposure of the C-terminal Domain. J Biol Chem 2015; 290:28584-28593. [PMID: 26405031 DOI: 10.1074/jbc.m115.678441] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Indexed: 01/05/2023] Open
Abstract
Hepatitis B virus core protein has 183 amino acids divided into an assembly domain and an arginine-rich C-terminal domain (CTD) that regulates essential functions including genome packaging, reverse transcription, and intracellular trafficking. Here, we investigated the CTD in empty hepatitis B virus (HBV) T=4 capsids. We examined wild-type core protein (Cp183-WT) and a mutant core protein (Cp183-EEE), in which three CTD serines are replaced with glutamate to mimic phosphorylated protein. We found that Cp183-WT capsids were less stable than Cp183-EEE capsids. When we tested CTD sensitivity to trypsin, we detected two different populations of CTDs differentiated by their rate of trypsin cleavage. Interestingly, CTDs from Cp183-EEE capsids exhibited a much slower rate of proteolytic cleavage when compared with CTDs of Cp183-WT capsids. Cryo-electron microscopy studies of trypsin-digested capsids show that CTDs at five-fold symmetry vertices are most protected. We hypothesize that electrostatic interactions between glutamates and arginines in Cp183-EEE, particularly at five-fold, increase capsid stability and reduce CTD exposure. Our studies show that quasi-equivalent CTDs exhibit different rates of exposure and thus might perform distinct functions during the hepatitis B virus lifecycle. Our results demonstrate a structural role for CTD phosphorylation and indicate crosstalk between CTDs within a capsid particle.
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Affiliation(s)
- Lisa Selzer
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Ravi Kant
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - Joseph C-Y Wang
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - Adam Zlotnick
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405.
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50
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Abstract
Cooperativity in human glucokinase (GCK), the body's primary glucose sensor and a major determinant of glucose homeostatic diseases, is fundamentally different from textbook models of allostery because GCK is monomeric and contains only one glucose-binding site. Prior work has demonstrated that millisecond timescale order-disorder transitions within the enzyme's small domain govern cooperativity. Here, using limited proteolysis, we map the site of disorder in unliganded GCK to a 30-residue active-site loop that closes upon glucose binding. Positional randomization of the loop, coupled with genetic selection in a glucokinase-deficient bacterium, uncovers a hyperactive GCK variant with substantially reduced cooperativity. Biochemical and structural analysis of this loop variant and GCK variants associated with hyperinsulinemic hypoglycemia reveal two distinct mechanisms of enzyme activation. In α-type activation, glucose affinity is increased, the proteolytic susceptibility of the active site loop is suppressed and the (1)H-(13)C heteronuclear multiple quantum coherence (HMQC) spectrum of (13)C-Ile-labeled enzyme resembles the glucose-bound state. In β-type activation, glucose affinity is largely unchanged, proteolytic susceptibility of the loop is enhanced, and the (1)H-(13)C HMQC spectrum reveals no perturbation in ensemble structure. Leveraging both activation mechanisms, we engineer a fully noncooperative GCK variant, whose functional properties are indistinguishable from other hexokinase isozymes, and which displays a 100-fold increase in catalytic efficiency over wild-type GCK. This work elucidates specific structural features responsible for generating allostery in a monomeric enzyme and suggests a general strategy for engineering cooperativity into proteins that lack the structural framework typical of traditional allosteric systems.
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