1
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Murciano-Calles J, Rodríguez-Martínez A, Palencia A, Andújar-Sánchez M, Iglesias-Bexiga M, Corbi-Verge C, Buzón P, Ruiz-Sanz J, Martínez JC, Pérez-Sánchez H, Cámara-Artigas A, Luque I. Phage display identification of high-affinity ligands for human TSG101-UEV: A structural and thermodynamic study of PTAP recognition. Int J Biol Macromol 2024; 274:133233. [PMID: 38901510 DOI: 10.1016/j.ijbiomac.2024.133233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/06/2024] [Accepted: 06/15/2024] [Indexed: 06/22/2024]
Abstract
The ubiquitin E2 variant domain of TSG101 (TSG101-UEV) plays a pivotal role in protein sorting and virus budding by recognizing PTAP motifs within ubiquitinated proteins. Disrupting TSG101-UEV/PTAP interactions has emerged as a promising strategy for the development of novel host-oriented antivirals with a broad spectrum of action. Nonetheless, finding inhibitors with good properties as therapeutic agents remains a challenge since the key determinants of binding affinity and specificity are still poorly understood. Here we present a detailed thermodynamic, structural, and dynamic characterization viral PTAP Late domain recognition by TSG101-UEV, combining isothermal titration calorimetry, X-ray diffraction structural studies, molecular dynamics simulations, and computational analysis of intramolecular communication pathways. Our analysis highlights key contributions from conserved hydrophobic contacts and water-mediated hydrogen bonds at the PTAP binding interface. We have identified additional electrostatic hotspots adjacent to the core motif that modulate affinity. Using competitive phage display screening we have improved affinity by 1-2 orders of magnitude, producing novel peptides with low micromolar affinities that combine critical elements found in the best natural binders. Molecular dynamics simulations revealed that optimized peptides engage new pockets on the UEV domain surface. This study provides a comprehensive view of the molecular forces directing TSG101-UEV recognition of PTAP motifs, revealing that binding is governed by conserved structural elements yet tuneable through targeted optimization. These insights open new venues to design inhibitors targeting TSG101-dependent pathways with potential application as novel broad-spectrum antivirals.
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Affiliation(s)
- Javier Murciano-Calles
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Alejandro Rodríguez-Martínez
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain; Structural Bioinformatics and High-Performance Computing (BIO-HPC) Research Group, Universidad Católica de Murcia (UCAM), Guadalupe, Spain
| | - Andrés Palencia
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Montserrat Andújar-Sánchez
- Department of Chemistry and Physics, Agrifood Campus of International Excellence (ceiA3) and CIAMBITAL, University of Almería, Carretera de Sacramento s/n 04120 Almería, Spain
| | - Manuel Iglesias-Bexiga
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Carles Corbi-Verge
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Pedro Buzón
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Javier Ruiz-Sanz
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Jose C Martínez
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain
| | - Horacio Pérez-Sánchez
- Structural Bioinformatics and High-Performance Computing (BIO-HPC) Research Group, Universidad Católica de Murcia (UCAM), Guadalupe, Spain
| | - Ana Cámara-Artigas
- Department of Chemistry and Physics, Agrifood Campus of International Excellence (ceiA3) and CIAMBITAL, University of Almería, Carretera de Sacramento s/n 04120 Almería, Spain
| | - Irene Luque
- Department of Physical Chemistry, Institute of Biotechnology and Unit of Excellence in Chemistry applied to Biomedicine and Environment, University of Granada, 18071 Granada, Spain.
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2
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Grieco A, Ruiz-Fresneda MA, Gómez-Mulas A, Pacheco-García JL, Quereda-Moraleda I, Pey AL, Martin-Garcia JM. Structural dynamics at the active site of the cancer-associated flavoenzyme NQO1 probed by chemical modification with PMSF. FEBS Lett 2023; 597:2687-2698. [PMID: 37726177 DOI: 10.1002/1873-3468.14738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/02/2023] [Accepted: 08/29/2023] [Indexed: 09/21/2023]
Abstract
A large conformational heterogeneity of human NAD(P)H:quinone oxidoreductase 1 (NQO1), a flavoprotein associated with various human diseases, has been observed to occur in the catalytic site of the enzyme. Here, we report the X-ray structure of NQO1 with phenylmethylsulfonyl fluoride (PMSF) at 1.6 Å resolution. Activity assays confirmed that, despite being covalently bound to the Tyr128 residue at the catalytic site, PMSF did not abolish NQO1 activity. This may indicate that the PMSF molecule does not reduce the high flexibility of Tyr128, thus allowing NADH and DCPIP substrates to bind to the enzyme. Our results show that targeting Tyr128, a key residue in NQO1 function, with small covalently bound molecules could possibly not be a good drug discovery strategy to inhibit this enzyme.
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Affiliation(s)
- Alice Grieco
- Department of Crystallography & Structural Biology, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council (CSIC), Madrid, Spain
| | | | | | | | - Isabel Quereda-Moraleda
- Department of Crystallography & Structural Biology, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council (CSIC), Madrid, Spain
| | - Angel L Pey
- Department of Physical Chemistry, University of Granada, Granada, Spain
- Department of Physical Chemistry, Unit of Excellence in Applied Chemistry to Biomedicine and Environment, and Institute of Biotechnology, University of Granada, Granada, Spain
| | - Jose M Martin-Garcia
- Department of Crystallography & Structural Biology, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council (CSIC), Madrid, Spain
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3
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Mehrabipour M, Jasemi NSK, Dvorsky R, Ahmadian MR. A Systematic Compilation of Human SH3 Domains: A Versatile Superfamily in Cellular Signaling. Cells 2023; 12:2054. [PMID: 37626864 PMCID: PMC10453029 DOI: 10.3390/cells12162054] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
SRC homology 3 (SH3) domains are fundamental modules that enable the assembly of protein complexes through physical interactions with a pool of proline-rich/noncanonical motifs from partner proteins. They are widely studied modular building blocks across all five kingdoms of life and viruses, mediating various biological processes. The SH3 domains are also implicated in the development of human diseases, such as cancer, leukemia, osteoporosis, Alzheimer's disease, and various infections. A database search of the human proteome reveals the existence of 298 SH3 domains in 221 SH3 domain-containing proteins (SH3DCPs), ranging from 13 to 720 kilodaltons. A phylogenetic analysis of human SH3DCPs based on their multi-domain architecture seems to be the most practical way to classify them functionally, with regard to various physiological pathways. This review further summarizes the achievements made in the classification of SH3 domain functions, their binding specificity, and their significance for various diseases when exploiting SH3 protein modular interactions as drug targets.
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Affiliation(s)
- Mehrnaz Mehrabipour
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.M.); (N.S.K.J.)
| | - Neda S. Kazemein Jasemi
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.M.); (N.S.K.J.)
| | - Radovan Dvorsky
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.M.); (N.S.K.J.)
- Center for Interdisciplinary Biosciences, P. J. Šafárik University, 040 01 Košice, Slovakia
| | - Mohammad R. Ahmadian
- Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (M.M.); (N.S.K.J.)
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4
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Martinez JC, Ruiz-Sanz J, Resina MJ, Montero F, Camara-Artigas A, Luque I. A calorimetric and structural analysis of cooperativity in the thermal unfolding of the PDZ tandem of human Syntenin-1. Int J Biol Macromol 2023; 242:124662. [PMID: 37119899 DOI: 10.1016/j.ijbiomac.2023.124662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/10/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023]
Abstract
Syntenin-1 is a multidomain protein containing a central tandem of two PDZ domains flanked by two unnamed domains. Previous structural and biophysical studies show that the two PDZ domains are functional both isolated and in tandem, occurring a gain in their respective binding affinities when joined through its natural short linker. To get insight into the molecular and energetic reasons of such a gain, here, the first thermodynamic characterization of the conformational equilibrium of Syntenin-1 is presented, with special focus on its PDZ domains. These studies include the thermal unfolding of the whole protein, the PDZ-tandem construct and the two isolated PDZ domains using circular dichroism, differential scanning fluorimetry and differential scanning calorimetry. The isolated PDZ domains show low stability (ΔG < 10 kJ·mol-1) and poor cooperativity compared to the PDZ-tandem, which shows higher stability (20-30 kJ·mol-1) and a fully cooperative behaviour, with energetics similar to that previously described for archetypical PDZ domains. The high-resolution structures suggest that this remarkable increase in cooperativity is associated to strong, water-mediated, interactions at the interface between the PDZ domains, associated to nine conserved hydration regions. The low Tm value (45 °C), the anomalously high unfolding enthalpy (>400 kJ·mol-1), and native heat capacity values (above 40 kJ·K-1·mol-1), indicate that these interfacial buried waters play a relevant role in Syntenin-1 folding energetics.
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Affiliation(s)
- Jose C Martinez
- Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain.
| | - Javier Ruiz-Sanz
- Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain.
| | - María J Resina
- Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain.
| | - Fernando Montero
- Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain.
| | - Ana Camara-Artigas
- Department of Chemistry and Physics, Agrifood Campus of International Excellence (ceiA3) and CIAMBITAL, University of Almería, Carretera de Sacramento s/n, 04120 Almería, Spain.
| | - Irene Luque
- Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain.
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5
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Castillo F, Corbi-Verge C, Murciano-Calles J, Candel AM, Han Z, Iglesias-Bexiga M, Ruiz-Sanz J, Kim PM, Harty RN, Martinez JC, Luque I. Phage display identification of nanomolar ligands for human NEDD4-WW3: Energetic and dynamic implications for the development of broad-spectrum antivirals. Int J Biol Macromol 2022; 207:308-323. [PMID: 35257734 DOI: 10.1016/j.ijbiomac.2022.03.010] [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: 12/16/2021] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/29/2022]
Abstract
The recognition of PPxY viral Late domains by the third WW domain of the human HECT-E3 ubiquitin ligase NEDD4 (NEDD4-WW3) is essential for the budding of many viruses. Blocking these interactions is a promising strategy to develop broad-spectrum antivirals. As all WW domains, NEDD4-WW3 is a challenging therapeutic target due to the low binding affinity of its natural interactions, its high conformational plasticity, and its complex thermodynamic behavior. In this work, we set out to investigate whether high affinity can be achieved for monovalent ligands binding to the isolated NEDD4-WW3 domain. We show that a competitive phage-display set-up allows for the identification of high-affinity peptides showing inhibitory activity of viral budding. A detailed biophysical study combining calorimetry, nuclear magnetic resonance, and molecular dynamic simulations reveals that the improvement in binding affinity does not arise from the establishment of new interactions with the domain, but is associated to conformational restrictions imposed by a novel C-terminal -LFP motif in the ligand, unprecedented in the PPxY interactome. These results, which highlight the complexity of WW domain interactions, provide valuable insight into the key elements for high binding affinity, of interest to guide virtual screening campaigns for the identification of novel therapeutics targeting NEDD4-WW3 interactions.
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Affiliation(s)
- Francisco Castillo
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Carles Corbi-Verge
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain; Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics & Department of Computer Science, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Javier Murciano-Calles
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Adela M Candel
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Ziying Han
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce St., Philadelphia, PA 19104, USA
| | - Manuel Iglesias-Bexiga
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Javier Ruiz-Sanz
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Philip M Kim
- Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics & Department of Computer Science, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Ronald N Harty
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce St., Philadelphia, PA 19104, USA
| | - Jose C Martinez
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain
| | - Irene Luque
- Department of Physical Chemistry, Institute of Biotechnology and Excelence Unit in Chemistry Applied to Biomedicine and Environment, School of Sciences, University of Granada, Campus Fuentenueva s/n 18071, Granada, Spain.
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6
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Martinez JC, Castillo F, Ruiz-Sanz J, Murciano-Calles J, Camara-Artigas A, Luque I. Understanding binding affinity and specificity of modular protein domains: A focus in ligand design for the polyproline-binding families. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 130:161-188. [PMID: 35534107 DOI: 10.1016/bs.apcsb.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Within the modular protein domains there are five families that recognize proline-rich sequences: SH3, WW, EVH1, GYF and UEV domains. This chapter reviews the main strategies developed for the design of ligands for these families, including peptides, peptidomimetics and drugs. We also describe some studies aimed to understand the molecular reasons responsible for the intrinsic affinity and specificity of these domains.
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Affiliation(s)
- Jose C Martinez
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
| | - Francisco Castillo
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Parque Tecnológico Ciencias de la Salud, Granada, Spain
| | - Javier Ruiz-Sanz
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Javier Murciano-Calles
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Ana Camara-Artigas
- Departamento de Química Física, Universidad de Almería, Campus de Excelencia Internacional Agroalimentario ceiA3 y CIAMBITAL, Almeria, Spain
| | - Irene Luque
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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7
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Stadmiller SS, Aguilar JS, Waudby CA, Pielak GJ. Rapid Quantification of Protein-Ligand Binding via 19F NMR Lineshape Analysis. Biophys J 2020; 118:2537-2548. [PMID: 32348722 DOI: 10.1016/j.bpj.2020.03.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 03/19/2020] [Indexed: 12/14/2022] Open
Abstract
Fluorine incorporation is ideally suited to many NMR techniques, and incorporation of fluorine into proteins and fragment libraries for drug discovery has become increasingly common. Here, we use one-dimensional 19F NMR lineshape analysis to quantify the kinetics and equilibrium thermodynamics for the binding of a fluorine-labeled Src homology 3 (SH3) protein domain to four proline-rich peptides. SH3 domains are one of the largest and most well-characterized families of protein recognition domains and have a multitude of functions in eukaryotic cell signaling. First, we showe that fluorine incorporation into SH3 causes only minor structural changes to both the free and bound states using amide proton temperature coefficients. We then compare the results from lineshape analysis of one-dimensional 19F spectra to those from two-dimensional 1H-15N heteronuclear single quantum coherence spectra. Their agreement demonstrates that one-dimensional 19F lineshape analysis is a robust, low-cost, and fast alternative to traditional heteronuclear single quantum coherence-based experiments. The data show that binding is diffusion limited and indicate that the transition state is highly similar to the free state. We also measured binding as a function of temperature. At equilibrium, binding is enthalpically driven and arises from a highly positive activation enthalpy for association with small entropic contributions. Our results agree with those from studies using different techniques, providing additional evidence for the utility of 19F NMR lineshape analysis, and we anticipate that this analysis will be an effective tool for rapidly characterizing the energetics of protein interactions.
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Affiliation(s)
| | - Jhoan S Aguilar
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Christopher A Waudby
- Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Gary J Pielak
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina; Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina.
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8
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Shi J, Shen Q, Cho JH, Hwang W. Entropy Hotspots for the Binding of Intrinsically Disordered Ligands to a Receptor Domain. Biophys J 2020; 118:2502-2512. [PMID: 32311315 DOI: 10.1016/j.bpj.2020.03.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/28/2020] [Accepted: 03/23/2020] [Indexed: 11/18/2022] Open
Abstract
Proline-rich motifs (PRMs) are widely used for mediating protein-protein interactions with weak binding affinities. Because they are intrinsically disordered when unbound, conformational entropy plays a significant role for the binding. However, residue-level differences of the entropic contribution in the binding of different ligands remain not well understood. We use all-atom molecular dynamics simulation and the maximal information spanning tree formalism to analyze conformational entropy associated with the binding of two PRMs, one from the Abl kinase and the other from the nonstructural protein 1 of the 1918 Spanish influenza A virus, to the N-terminal SH3 (nSH3) domain of the CrkII protein. Side chains of the stably folded nSH3 experience more entropy change upon ligand binding than the backbone, whereas PRMs involve comparable but heterogeneous entropy changes among the backbone and side chains. In nSH3, two conserved nonpolar residues forming contacts with the PRM experience the largest side-chain entropy loss. In contrast, the C-terminal charged residues of PRMs that form polar contacts with nSH3 experience the greatest side-chain entropy loss, although their "fuzzy" nature is attributable to the backbone that remains relatively flexible. Thus, residues that form high-occupancy contacts between nSH3 and PRM do not reciprocally contribute to entropy loss. Furthermore, certain surface residues of nSH3 distal to the interface with PRMs gain entropy, indicating a nonlocal effect of ligand binding. Comparing between the PRMs from cAbl and nonstructural protein 1, the latter involves a larger side-chain entropy loss and forms more contacts with nSH3. Consistent with experiments, this indicates stronger binding of the viral ligand at the expense of losing the flexibility of side chains, whereas the backbone experiences less entropy loss. The entropy "hotspots" as identified in this study will be important for tuning the binding affinity of various ligands to a receptor.
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Affiliation(s)
- Jie Shi
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Qingliang Shen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Jae-Hyun Cho
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas; Department of Materials Science and Engineering, Texas A&M University, College Station, Texas; Department of Physics and Astronomy, Texas A&M University, College Station, Texas; School of Computational Sciences, Korea Institute for Advanced Study, Seoul, South Korea.
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9
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Binding site plasticity in viral PPxY Late domain recognition by the third WW domain of human NEDD4. Sci Rep 2019; 9:15076. [PMID: 31636332 PMCID: PMC6803667 DOI: 10.1038/s41598-019-50701-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/13/2019] [Indexed: 11/26/2022] Open
Abstract
The recognition of PPxY viral Late domains by the third WW domain of the HECT-E3 ubiquitin ligase NEDD4 (hNEDD4-WW3) is essential for the completion of the budding process of numerous enveloped viruses, including Ebola, Marburg, HTLV1 or Rabies. hNEDD4-WW3 has been validated as a promising target for the development of novel host-oriented broad spectrum antivirals. Nonetheless, finding inhibitors with good properties as therapeutic agents remains a challenge since the key determinants of binding affinity and specificity are still poorly understood. We present here a detailed structural and thermodynamic study of the interactions of hNEDD4-WW3 with viral Late domains combining isothermal titration calorimetry, NMR structural determination and molecular dynamics simulations. Structural and energetic differences in Late domain recognition reveal a highly plastic hNEDD4-WW3 binding site that can accommodate PPxY-containing ligands with varying orientations. These orientations are mostly determined by specific conformations adopted by residues I859 and T866. Our results suggest a conformational selection mechanism, extensive to other WW domains, and highlight the functional relevance of hNEDD4-WW3 domain conformational flexibility at the binding interface, which emerges as a key element to consider in the search for potent and selective inhibitors of therapeutic interest.
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10
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Ramos S, Horness RE, Collins JA, Haak D, Thielges MC. Site-specific 2D IR spectroscopy: a general approach for the characterization of protein dynamics with high spatial and temporal resolution. Phys Chem Chem Phys 2019; 21:780-788. [PMID: 30548035 PMCID: PMC6360950 DOI: 10.1039/c8cp06146g] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The conformational heterogeneity and dynamics of protein side chains contribute to function, but investigating exactly how is hindered by experimental challenges arising from the fast timescales involved and the spatial heterogeneity of protein structures. The potential of two-dimensional infrared (2D IR) spectroscopy for measuring conformational heterogeneity and dynamics with unprecedented spatial and temporal resolution has motivated extensive effort to develop amino acids with functional groups that have frequency-resolved absorptions to serve as probes of their protein microenvironments. We demonstrate the full advantage of the approach by selective incorporation of the probe p-cyanophenylalanine at six distinct sites in a Src homology 3 domain and the application of 2D IR spectroscopy to site-specifically characterize heterogeneity and dynamics and their contribution to cognate ligand binding. The approach revealed a wide range of microenvironments and distinct responses to ligand binding, including at the three adjacent, conserved aromatic residues that form the recognition surface of the protein. Molecular dynamics simulations performed for all the labeled proteins provide insight into the underlying heterogeneity and dynamics. Similar application of 2D IR spectroscopy and site-selective probe incorporation will allow for the characterization of heterogeneity and dynamics of other proteins, how heterogeneity and dynamics are affected by solvation and local structure, and how they might contribute to biological function.
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Affiliation(s)
- Sashary Ramos
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Rachel E. Horness
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jessica A. Collins
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David Haak
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Megan C. Thielges
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
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11
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Bhatt VS, Zeng D, Krieger I, Sacchettini JC, Cho JH. Binding Mechanism of the N-Terminal SH3 Domain of CrkII and Proline-Rich Motifs in cAbl. Biophys J 2017; 110:2630-2641. [PMID: 27332121 DOI: 10.1016/j.bpj.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/29/2016] [Accepted: 05/04/2016] [Indexed: 12/14/2022] Open
Abstract
The N-terminal Src homology 3 (nSH3) domain of a signaling adaptor protein, CT-10 regulator of kinase II (CrkII), recognizes proline-rich motifs (PRMs) of binding partners, such as cAbl kinase. The interaction between CrkII and cAbl kinase is involved in the regulation of cell spreading, microbial pathogenesis, and cancer metastasis. Here, we report the detailed biophysical characterizations of the interactions between the nSH3 domain of CrkII and PRMs in cAbl. We identified that the nSH3 domain of CrkII binds to three PRMs in cAbl with virtually identical affinities. Structural studies, by using x-ray crystallography and NMR spectroscopy, revealed that the binding modes of all three nSH3:PRM complexes are highly similar to each other. Van 't Hoff analysis revealed that nSH3:PRM interaction is associated with favorable enthalpy and unfavorable entropy change. The combination of experimentally determined thermodynamic parameters, structure-based calculations, and (15)N NMR relaxation analysis highlights the energetic contribution of conformational entropy change upon the complex formation, and water molecules structured in the binding interface of the nSH3:PRM complex. Understanding the molecular basis of nSH3:PRM interaction will provide, to our knowledge, new insights for the rational design of small molecules targeting the interaction between CrkII and cAbl.
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Affiliation(s)
- Veer S Bhatt
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Danyun Zeng
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Inna Krieger
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - James C Sacchettini
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Jae-Hyun Cho
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.
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12
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Arya R, Dangi RS, Makwana PK, Kumar A, Upadhyay SK, Sundd M. Grb2 carboxyl-terminal SH3 domain can bivalently associate with two ligands, in an SH3 dependent manner. Sci Rep 2017; 7:1284. [PMID: 28455498 PMCID: PMC5430726 DOI: 10.1038/s41598-017-01364-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/28/2017] [Indexed: 11/09/2022] Open
Abstract
Src homology domain containing leukocyte protein of 65 kDa (SLP65), the growth factor receptor binding protein 2 (Grb2), and the guanine nucleotide exchange factor for the Rho family GTPases (Vav), self associate in unstimulated B cells as components of the preformed B cell receptor transducer module, in an SH3-dependent manner. The complex enables the B cell to promptly respond to BCR aggregation, resulting in signal amplification. It also facilitates Vav translocation to the membrane rafts, for activation. Here we uncover the molecular mechanism by which the complex may be formed in the B cell. The C-terminal SH3 domain (SH3C) of Grb2 bivalently interacts with the atypical non-PxxP proline rich region of SLP65, and the N-terminal SH3 domain (SH3N) of Vav, both the interactions crucial for the proper functioning of the B cell. Most surprisingly, the two ligands bind the same ligand binding site on the surface of Grb2 SH3C. Addition of SLP65 peptide to the Grb2-Vav complex abrogates the interaction completely, displacing Vav. However, the addition of Vav SH3N to the SLP65-Grb2 binary complex, results in a trimeric complex. Extrapolating these results to the in vivo conditions, Grb2 should bind the SLP65 transducer module first, and then Vav should associate.
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Affiliation(s)
- Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India
| | - Rohit Singh Dangi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110 067, India
| | - Pinakin K Makwana
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110 067, India
| | - Ambrish Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110 067, India
| | - Santosh Kumar Upadhyay
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110 020, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110 067, India.
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13
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Camara-Artigas A, Ortiz-Salmeron E, Andujar-Sánchez M, Bacarizo J, Martin-Garcia JM. The role of water molecules in the binding of class I and II peptides to the SH3 domain of the Fyn tyrosine kinase. Acta Crystallogr F Struct Biol Commun 2016; 72:707-12. [PMID: 27599862 PMCID: PMC5012211 DOI: 10.1107/s2053230x16012310] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/29/2016] [Indexed: 01/05/2023] Open
Abstract
Interactions of proline-rich motifs with SH3 domains are present in signal transduction and other important cell processes. Analysis of structural and thermodynamic data suggest a relevant role of water molecules in these protein-protein interactions. To determine whether or not the SH3 domain of the Fyn tyrosine kinase shows the same behaviour, the crystal structures of its complexes with two high-affinity synthetic peptides, VSL12 and APP12, which are class I and II peptides, respectively, have been solved. In the class I complexes two water molecules were found at the binding interface that were not present in the class II complexes. The structures suggest a role of these water molecules in facilitating conformational changes in the SH3 domain to allow the binding of the class I or II peptides. In the third binding pocket these changes modify the cation-π and salt-bridge interactions that determine the affinity of the binding. Comparison of the water molecules involved in the binding of the peptides with previous reported hydration spots suggests a different pattern for the SH3 domains of the Src tyrosine kinase family.
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Affiliation(s)
- Ana Camara-Artigas
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento, 04120 Almeria, Spain
| | - Emilia Ortiz-Salmeron
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento, 04120 Almeria, Spain
| | - Montserrrat Andujar-Sánchez
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento, 04120 Almeria, Spain
| | - Julio Bacarizo
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento, 04120 Almeria, Spain
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14
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15
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Iglesias-Bexiga M, Castillo F, Cobos ES, Oka T, Sudol M, Luque I. WW domains of the yes-kinase-associated-protein (YAP) transcriptional regulator behave as independent units with different binding preferences for PPxY motif-containing ligands. PLoS One 2015; 10:e0113828. [PMID: 25607641 PMCID: PMC4301871 DOI: 10.1371/journal.pone.0113828] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 10/31/2014] [Indexed: 12/28/2022] Open
Abstract
YAP is a WW domain-containing effector of the Hippo tumor suppressor pathway, and the object of heightened interest as a potent oncogene and stemness factor. YAP has two major isoforms that differ in the number of WW domains they harbor. Elucidating the degree of co-operation between these WW domains is important for a full understanding of the molecular function of YAP. We present here a detailed biophysical study of the structural stability and binding properties of the two YAP WW domains aimed at investigating the relationship between both domains in terms of structural stability and partner recognition. We have carried out a calorimetric study of the structural stability of the two YAP WW domains, both isolated and in a tandem configuration, and their interaction with a set of functionally relevant ligands derived from PTCH1 and LATS kinases. We find that the two YAP WW domains behave as independent units with different binding preferences, suggesting that the presence of the second WW domain might contribute to modulate target recognition between the two YAP isoforms. Analysis of structural models and phage-display studies indicate that electrostatic interactions play a critical role in binding specificity. Together, these results are relevant to understand of YAP function and open the door to the design of highly specific ligands of interest to delineate the functional role of each WW domain in YAP signaling.
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Affiliation(s)
- Manuel Iglesias-Bexiga
- Department of Physical Chemistry and Institute of Biotechnology, Faculty of Sciences, University of Granada, 18071, Granada, Spain
| | - Francisco Castillo
- Department of Physical Chemistry and Institute of Biotechnology, Faculty of Sciences, University of Granada, 18071, Granada, Spain
| | - Eva S. Cobos
- Department of Physical Chemistry and Institute of Biotechnology, Faculty of Sciences, University of Granada, 18071, Granada, Spain
| | - Tsutomu Oka
- Weis Center for Research, Geisinger Clinic, M.C. 26–08, 100 North Academy Avenue, Danville, PA, 17822–2608, United States of America
| | - Marius Sudol
- Weis Center for Research, Geisinger Clinic, M.C. 26–08, 100 North Academy Avenue, Danville, PA, 17822–2608, United States of America
| | - Irene Luque
- Department of Physical Chemistry and Institute of Biotechnology, Faculty of Sciences, University of Granada, 18071, Granada, Spain
- * E-mail:
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16
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Bacarizo J, Martínez-Rodríguez S, Cámara-Artigas A. Structure of the c-Src-SH3 domain in complex with a proline-rich motif of NS5A protein from the hepatitis C virus. J Struct Biol 2014; 189:67-72. [PMID: 25447263 DOI: 10.1016/j.jsb.2014.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022]
Abstract
The non-structural hepatitis C virus proteins NS5A and NS5B form a complex through interaction with the SH2 and SH3 domains of the non-receptor Src tyrosine kinase, which seems essential for viral replication. We have crystallized the complex between the SH3 domain of the c-Src tyrosine kinase and the C-terminal proline rich motif of the NS5A protein (A349PPIPPPRRKR359). Crystals obtained at neutral pH belong to the space group I41, with a single molecule of the SH3/NS5A complex at the asymmetric unit. The NS5A peptide is bound in a reverse orientation (class II) and the comparison of this structure with those of the high affinity synthetic peptides APP12 and VSL12 shows some important differences at the salt bridge that drives the peptide orientation. Further conformational changes in residues placed apart from the binding site also seem to play an important role in the binding orientation of this peptide. Our results show the interaction of the SH3 domain of the c-Src tyrosine kinase with a proline rich motif in the NS5A protein and point to their potential interaction in vivo.
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Affiliation(s)
- Julio Bacarizo
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento s/n, Almería 04120, Spain
| | - Sergio Martínez-Rodríguez
- Department of Physical Chemistry, University of Granada, Avda. de Fuentenueva s/n, Granada 18071, Spain
| | - Ana Cámara-Artigas
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento s/n, Almería 04120, Spain.
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17
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Fine-tuned broad binding capability of human lipocalin-type prostaglandin D synthase for various small lipophilic ligands. FEBS Lett 2014; 588:962-9. [DOI: 10.1016/j.febslet.2014.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 01/30/2014] [Accepted: 02/03/2014] [Indexed: 11/22/2022]
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18
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Schuchardt BJ, Bhat V, Mikles DC, McDonald CB, Sudol M, Farooq A. Molecular origin of the binding of WWOX tumor suppressor to ErbB4 receptor tyrosine kinase. Biochemistry 2013; 52:9223-36. [PMID: 24308844 DOI: 10.1021/bi400987k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The ability of WWOX tumor suppressor to physically associate with the intracellular domain (ICD) of ErbB4 receptor tyrosine kinase is believed to play a central role in downregulating the transcriptional function of the latter. Herein, using various biophysical methods, we show that while the WW1 domain of WWOX binds to PPXY motifs located within the ICD of ErbB4 in a physiologically relevant manner, the WW2 domain does not. Importantly, while the WW1 domain absolutely requires the integrity of the PPXY consensus sequence, nonconsensus residues within and flanking this motif do not appear to be critical for binding. This strongly suggests that the WW1 domain of WWOX is rather promiscuous toward its cellular partners. We also provide evidence that the lack of binding of the WW2 domain of WWOX to PPXY motifs is due to the replacement of a signature tryptophan, lining the hydrophobic ligand binding groove, with tyrosine (Y85). Consistent with this notion, the Y85W substitution within the WW2 domain exquisitely restores its binding to PPXY motifs in a manner akin to the binding of the WW1 domain of WWOX. Of particular significance is the observation that the WW2 domain augments the binding of the WW1 domain to ErbB4, implying that the former serves as a chaperone within the context of the WW1-WW2 tandem module of WWOX in agreement with our findings reported previously. Altogether, our study sheds new light on the molecular basis of an important WW-ligand interaction involved in mediating a plethora of cellular processes.
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Affiliation(s)
- Brett J Schuchardt
- Department of Biochemistry and Molecular Biology, Leonard Miller School of Medicine, University of Miami , Miami, Florida 33136, United States
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19
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DFT and docking studies of rhodostreptomycins A and B and their interactions with solvated/nonsolvated Mg²⁺ and Ca²⁺ ions. J Mol Model 2013; 19:4823-36. [PMID: 24026575 DOI: 10.1007/s00894-013-1952-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 07/17/2013] [Indexed: 12/17/2022]
Abstract
The interactions of L-aminoglucosidic stereoisomers such as rhodostreptomycins A (Rho A) and B (Rho B) with cations (Mg(2+), Ca(2+), and H(+)) were studied by a quantum mechanical method that utilized DFT with B3LYP/6-311G. Docking studies were also carried out in order to explore the surface recognition properties of L-aminoglucoside with respect to Mg(2+) and Ca(2+) ions under solvated and nonsolvated conditions. Although both of the stereoisomers possess similar physicochemical/antibiotic properties against Helicobacter pylori, the thermochemical values for these complexes showed that its high affinity for Mg(2+) cations caused the hydration of Rho B. According to the results of the calculations, for Rho A-Ca(2+)(H2O)6, ΔH = -72.21 kcal mol(-1); for Rho B-Ca(2+)(H2O)6, ΔH = -72.53 kcal mol(-1); for Rho A-Mg(2+)(H2O)6, ΔH = -72.99 kcal mol(-1) and for Rho B-Mg(2+)(H2O)6, ΔH = -95.00 kcal mol(-1), confirming that Rho B binds most strongly with hydrated Mg(2+), considering the energy associated with this binding process. This result suggests that Rho B forms a more stable complex than its isomer does with magnesium ion. Docking results show that both of these rhodostreptomycin molecules bind to solvated Ca(2+) or Mg(2+) through hydrogen bonding. Finally, Rho B is more stable than Rho A when protonation occurs.
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20
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Holt C, Carver JA, Ecroyd H, Thorn DC. Invited review: Caseins and the casein micelle: their biological functions, structures, and behavior in foods. J Dairy Sci 2013; 96:6127-46. [PMID: 23958008 DOI: 10.3168/jds.2013-6831] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/09/2013] [Indexed: 12/27/2022]
Abstract
A typical casein micelle contains thousands of casein molecules, most of which form thermodynamically stable complexes with nanoclusters of amorphous calcium phosphate. Like many other unfolded proteins, caseins have an actual or potential tendency to assemble into toxic amyloid fibrils, particularly at the high concentrations found in milk. Fibrils do not form in milk because an alternative aggregation pathway is followed that results in formation of the casein micelle. As a result of forming micelles, nutritious milk can be secreted and stored without causing either pathological calcification or amyloidosis of the mother's mammary tissue. The ability to sequester nanoclusters of amorphous calcium phosphate in a stable complex is not unique to caseins. It has been demonstrated using a number of noncasein secreted phosphoproteins and may be of general physiological importance in preventing calcification of other biofluids and soft tissues. Thus, competent noncasein phosphoproteins have similar patterns of phosphorylation and the same type of flexible, unfolded conformation as caseins. The ability to suppress amyloid fibril formation by forming an alternative amorphous aggregate is also not unique to caseins and underlies the action of molecular chaperones such as the small heat-shock proteins. The open structure of the protein matrix of casein micelles is fragile and easily perturbed by changes in its environment. Perturbations can cause the polypeptide chains to segregate into regions of greater and lesser density. As a result, the reliable determination of the native structure of casein micelles continues to be extremely challenging. The biological functions of caseins, such as their chaperone activity, are determined by their composition and flexible conformation and by how the casein polypeptide chains interact with each other. These same properties determine how caseins behave in the manufacture of many dairy products and how they can be used as functional ingredients in other foods.
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Affiliation(s)
- C Holt
- Institute of Molecular, Cell and Systems Biology, School of Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
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21
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Bacarizo J, Camara-Artigas A. Atomic resolution structures of the c-Src SH3 domain in complex with two high-affinity peptides from classes I and II. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:756-66. [PMID: 23633584 DOI: 10.1107/s0907444913001522] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 01/15/2013] [Indexed: 12/20/2022]
Abstract
The atomic resolution crystal structures of complexes between the SH3 domain of the c-Src tyrosine kinase and two high-affinity peptides belonging to class I and class II have been solved. The crystals of the Thr98Asp and Thr98Glu mutants in complex with the APP12 peptide (APPLPPRNRPRL) belonged to the trigonal space group P3121 and in both cases the asymmetric unit was composed of one molecule of the SH3-APP12 complex. The crystals of the Thr98Glu mutant in complex with the VSL12 peptide (VSLARRPLPLP) belonged to the trigonal space group P3221 and the asymmetric unit was also composed of a single molecule of the SH3-VSL12 complex. All crystals were obtained in the presence of PEG 300 under the same conditions as reported for the intertwined dimeric structure of the c-Src SH3 domain, but the presence of the peptide stabilizes the monomeric form of the domain. These structures allow a detailed analysis of the role of salt bridges, cation-π interactions and hydrogen bonds in the binding of proline-rich motifs to the c-Src SH3 domain. Moreover, these crystallographic structures allow the role of water molecules in the binding of these motifs to the c-Src SH3 domain to be studied for the first time.
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Affiliation(s)
- Julio Bacarizo
- Department of Chemistry and Physics, University of Almería, Agrifood Campus of International Excellence, Carretera de Sacramento, 04120 Almería, Spain
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Morgan AA, Rubenstein E. Proline: the distribution, frequency, positioning, and common functional roles of proline and polyproline sequences in the human proteome. PLoS One 2013; 8:e53785. [PMID: 23372670 PMCID: PMC3556072 DOI: 10.1371/journal.pone.0053785] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/05/2012] [Indexed: 11/19/2022] Open
Abstract
Proline is an anomalous amino acid. Its nitrogen atom is covalently locked within a ring, thus it is the only proteinogenic amino acid with a constrained phi angle. Sequences of three consecutive prolines can fold into polyproline helices, structures that join alpha helices and beta pleats as architectural motifs in protein configuration. Triproline helices are participants in protein-protein signaling interactions. Longer spans of repeat prolines also occur, containing as many as 27 consecutive proline residues. Little is known about the frequency, positioning, and functional significance of these proline sequences. Therefore we have undertaken a systematic bioinformatics study of proline residues in proteins. We analyzed the distribution and frequency of 687,434 proline residues among 18,666 human proteins, identifying single residues, dimers, trimers, and longer repeats. Proline accounts for 6.3% of the 10,882,808 protein amino acids. Of all proline residues, 4.4% are in trimers or longer spans. We detected patterns that influence function based on proline location, spacing, and concentration. We propose a classification based on proline-rich, polyproline-rich, and proline-poor status. Whereas singlet proline residues are often found in proteins that display recurring architectural patterns, trimers or longer proline sequences tend be associated with the absence of repetitive structural motifs. Spans of 6 or more are associated with DNA/RNA processing, actin, and developmental processes. We also suggest a role for proline in Kruppel-type zinc finger protein control of DNA expression, and in the nucleation and translocation of actin by the formin complex.
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Affiliation(s)
- Alexander A. Morgan
- Department of Biochemistry and Genome Technology Center, Stanford University Medical School, Stanford, California, United States of America
| | - Edward Rubenstein
- Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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Andujar-Sanchez M, Cobos ES, Luque I, Martinez JC. Thermodynamic impact of embedded water molecules in the unfolding of human CD2BP2-GYF domain. J Phys Chem B 2012; 116:7168-75. [PMID: 22624583 DOI: 10.1021/jp303495b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
GYF domains are small polyproline-recognition modules adopting a structural arrangement consisting of a single α-helix packed against a small β-sheet. Although most families of proline-rich recognition modules have been extensively characterized in terms of function, structure, or conformational flexibility, little is known about GYF domain functionality and folding. We have undertaken the thermodynamic characterization of the unfolding of CD2BP2-GYF domain by combining differential scanning calorimetry and circular dichroism under different pH conditions. The experimental data can be well-described in terms of a two-state equilibrium, although an unusually high heat capacity of the native state reflects a considerable conformational flexibility and dynamics of CD2BP2-GYF domain. In addition, the normalized thermodynamic parameters of unfolding (enthalpy, entropy and heat capacity) are roughly a factor of two greater than expected. In contrast, stability curves reveal an ordinary unfolding behavior of CD2BP2-GYF domain in terms of Gibbs energies, incurring thus unusually strong enthalpy-entropy compensation. This phenomenon, previously described as "thermodynamic homeostasis", has been associated in different examples to the contribution of occluded water (solvent) molecules into the protein structure. By means of CASTp server, we have found seven cavities/pockets scattered throughout of the CD2BP2-GYF structure, each able to harbor at least one water molecule. This structural feature provides rationalization for the atypical enthalpy values observed for CD2BP2-GYF because each water molecule is able to organize an extra amount of hydrogen bonds in the native state. In addition, these bound waters increase the vibrational entropy of the protein, which could also be responsible for an increase in protein flexibility and may thus fully explain the homeostatic behavior experimentally observed.
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Affiliation(s)
- Montserrat Andujar-Sanchez
- Department of Physical Chemistry, Biochemistry and Inorganic Chemistry, University of Almeria, Agrifood Campus of International Excellence (ceiA3), Carretera de Sacramento, 04120 Almeria, Spain
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Interfacial water molecules in SH3 interactions: Getting the full picture on polyproline recognition by protein-protein interaction domains. FEBS Lett 2012; 586:2619-30. [DOI: 10.1016/j.febslet.2012.04.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 04/27/2012] [Accepted: 04/30/2012] [Indexed: 01/16/2023]
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