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Ohkubo YZ, Radulovic PW, Kahira AN, Madsen JJ. Membrane binding and lipid-protein interaction of the C2 domain from coagulation factor V. Curr Res Struct Biol 2024; 7:100149. [PMID: 38766652 PMCID: PMC11098723 DOI: 10.1016/j.crstbi.2024.100149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 03/28/2024] [Accepted: 04/29/2024] [Indexed: 05/22/2024] Open
Abstract
Anchoring of coagulation factors to anionic regions of the membrane involves the C2 domain as a key player. The rate of enzymatic reactions of the coagulation factors is increased by several orders of magnitude upon membrane binding. However, the precise mechanisms behind the rate acceleration remain unclear, primarily because of a lack of understanding of the conformational dynamics of the C2-containing factors and corresponding complexes. We elucidate the membrane-bound form of the C2 domain from human coagulation factor V (FV-C2) by characterizing its membrane binding the specific lipid-protein interactions. Employing all-atom molecular dynamics simulations and leveraging the highly mobile membrane-mimetic (HMMM) model, we observed spontaneous binding of FV-C2 to a phosphatidylserine (PS)-containing membrane within 2-25 ns across twelve independent simulations. FV-C2 interacted with the membrane through three loops (spikes 1-3), achieving a converged, stable orientation. Multiple HMMM trajectories of the spontaneous membrane binding provided extensive sampling and ample data to examine the membrane-induced effects on the conformational dynamics of C2 as well as specific lipid-protein interactions. Despite existing crystal structures representing presumed "open" and "closed" states of FV-C2, our results revealed a continuous distribution of structures between these states, with the most populated structures differing from both "open" and "closed" states observed in crystal environments. Lastly, we characterized a putative PS-specific binding site formed by K23, Q48, and S78 located in the groove enclosed by spikes 1-3 (PS-specificity pocket), suggesting a different orientation of a bound headgroup moiety compared to previous proposals based upon analysis of static crystal structures.
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Affiliation(s)
- Y. Zenmei Ohkubo
- Department of Bioinformatics, School of Life and Natural Sciences, Abdullah Gül University, Kayseri, Turkey
| | - Peter W. Radulovic
- Graduate Programs, Taneja College of Pharmacy, University of South Florida, Tampa, FL 33612, USA
| | - Albert N. Kahira
- Graduate Programs, School of Engineering, Abdullah Gül University, Kayseri, Turkey
| | - Jesper J. Madsen
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
- Center for Global Health and Infectious Diseases Research, Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL 33612, USA
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2
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Sacco MD, Hammond LR, Noor RE, Bhattacharya D, McKnight LJ, Madsen JJ, Zhang X, Butler SG, Kemp MT, Jaskolka-Brown AC, Khan SJ, Gelis I, Eswara P, Chen Y. Staphylococcus aureus FtsZ and PBP4 bind to the conformationally dynamic N-terminal domain of GpsB. eLife 2024; 13:e85579. [PMID: 38639993 PMCID: PMC11062636 DOI: 10.7554/elife.85579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/15/2024] [Indexed: 04/20/2024] Open
Abstract
In the Firmicutes phylum, GpsB is a membrane associated protein that coordinates peptidoglycan synthesis with cell growth and division. Although GpsB has been studied in several bacteria, the structure, function, and interactome of Staphylococcus aureus GpsB is largely uncharacterized. To address this knowledge gap, we solved the crystal structure of the N-terminal domain of S. aureus GpsB, which adopts an atypical, asymmetric dimer, and demonstrates major conformational flexibility that can be mapped to a hinge region formed by a three-residue insertion exclusive to Staphylococci. When this three-residue insertion is excised, its thermal stability increases, and the mutant no longer produces a previously reported lethal phenotype when overexpressed in Bacillus subtilis. In S. aureus, we show that these hinge mutants are less functional and speculate that the conformational flexibility imparted by the hinge region may serve as a dynamic switch to fine-tune the function of the GpsB complex and/or to promote interaction with its various partners. Furthermore, we provide the first biochemical, biophysical, and crystallographic evidence that the N-terminal domain of GpsB binds not only PBP4, but also FtsZ, through a conserved recognition motif located on their C-termini, thus coupling peptidoglycan synthesis to cell division. Taken together, the unique structure of S. aureus GpsB and its direct interaction with FtsZ/PBP4 provide deeper insight into the central role of GpsB in S. aureus cell division.
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Affiliation(s)
- Michael D Sacco
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Lauren R Hammond
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Radwan E Noor
- Department of Chemistry, University of South FloridaTampaUnited States
| | | | - Lily J McKnight
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Jesper J Madsen
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
- Global and Planetary Health, College of Public Health, University of South FloridaTampaUnited States
| | - Xiujun Zhang
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Shane G Butler
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - M Trent Kemp
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Aiden C Jaskolka-Brown
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
| | - Sebastian J Khan
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Ioannis Gelis
- Department of Chemistry, University of South FloridaTampaUnited States
| | - Prahathees Eswara
- Department of Molecular Biosciences, University of South FloridaTampaUnited States
| | - Yu Chen
- Department of Molecular Medicine, Morsani College of Medicine, University of South FloridaTampaUnited States
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Lewandowski EM, Zhang X, Tan H, Jaskolka-Brown A, Kohaal N, Frazier A, Madsen JJ, Jacobs LMC, Wang J, Chen Y. Distal Protein-Protein Interactions Contribute to SARS-CoV-2 Main Protease Substrate Binding and Nirmatrelvir Resistance. bioRxiv 2024:2024.04.01.587566. [PMID: 38617221 PMCID: PMC11014590 DOI: 10.1101/2024.04.01.587566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
SARS-CoV-2 main protease, M pro , is responsible for the processing of the viral polyproteins into individual proteins, including the protease itself. M pro is a key target of anti-COVID-19 therapeutics such as nirmatrelvir (the active component of Paxlovid). Resistance mutants identified clinically and in viral passage assays contain a combination of active site mutations (e.g. E166V, E166A, L167F), which reduce inhibitor binding and enzymatic activity, and non-active site mutations (e.g. P252L, T21I, L50F), which restore the fitness of viral replication. Although the mechanism of resistance for the active site mutations is apparent, the role of the non-active site mutations in fitness rescue remains elusive. In this study, we use the model system of a M pro triple mutant (L50F/E166A/L167F) that confers not only nirmatrelvir drug resistance but also a similar fitness of replication compared to the wild-type both in vitro and in vivo. By comparing peptide and full-length M pro protein as substrates, we demonstrate that the binding of M pro substrate involves more than residues in the active site. In particular, L50F and other non-active site mutations can enhance the M pro dimer-dimer interactions and help place the nsp5-6 substrate at the enzyme catalytic center. The structural and enzymatic activity data of M pro L50F, L50F/E166A/L167F, and others underscore the importance of considering the whole substrate protein in studying M pro and substrate interactions, and offers important insights into M pro function, resistance development, and inhibitor design.
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Kiirikki AM, Antila HS, Bort LS, Buslaev P, Favela-Rosales F, Ferreira TM, Fuchs PFJ, Garcia-Fandino R, Gushchin I, Kav B, Kučerka N, Kula P, Kurki M, Kuzmin A, Lalitha A, Lolicato F, Madsen JJ, Miettinen MS, Mingham C, Monticelli L, Nencini R, Nesterenko AM, Piggot TJ, Piñeiro Á, Reuter N, Samantray S, Suárez-Lestón F, Talandashti R, Ollila OHS. Overlay databank unlocks data-driven analyses of biomolecules for all. Nat Commun 2024; 15:1136. [PMID: 38326316 PMCID: PMC10850068 DOI: 10.1038/s41467-024-45189-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/17/2024] [Indexed: 02/09/2024] Open
Abstract
Tools based on artificial intelligence (AI) are currently revolutionising many fields, yet their applications are often limited by the lack of suitable training data in programmatically accessible format. Here we propose an effective solution to make data scattered in various locations and formats accessible for data-driven and machine learning applications using the overlay databank format. To demonstrate the practical relevance of such approach, we present the NMRlipids Databank-a community-driven, open-for-all database featuring programmatic access to quality-evaluated atom-resolution molecular dynamics simulations of cellular membranes. Cellular membrane lipid composition is implicated in diseases and controls major biological functions, but membranes are difficult to study experimentally due to their intrinsic disorder and complex phase behaviour. While MD simulations have been useful in understanding membrane systems, they require significant computational resources and often suffer from inaccuracies in model parameters. Here, we demonstrate how programmable interface for flexible implementation of data-driven and machine learning applications, and rapid access to simulation data through a graphical user interface, unlock possibilities beyond current MD simulation and experimental studies to understand cellular membranes. The proposed overlay databank concept can be further applied to other biomolecules, as well as in other fields where similar barriers hinder the AI revolution.
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Affiliation(s)
- Anne M Kiirikki
- University of Helsinki, Institute of Biotechnology, Helsinki, Finland
| | - Hanne S Antila
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway
| | - Lara S Bort
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany
- University of Potsdam, Institute of Physics and Astronomy, 14476, Potsdam-Golm, Germany
| | - Pavel Buslaev
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, 40014, Jyväskylä, Finland
| | - Fernando Favela-Rosales
- Departamento de Ciencias Básicas, Tecnológico Nacional de México - ITS Zacatecas Occidente, Sombrerete, 99102, Zacatecas, Mexico
| | - Tiago Mendes Ferreira
- NMR group - Institute for Physics, Martin Luther University Halle-Wittenberg, 06120, Halle (Saale), Germany
| | - Patrick F J Fuchs
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), F-75005, Paris, France
- Université Paris Cité, F-75006, Paris, France
| | - Rebeca Garcia-Fandino
- Center for Research in Biological Chemistry and Molecular Materials (CiQUS), Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain
| | | | - Batuhan Kav
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428, Jülich, Germany
- ariadne.ai GmbH (Germany), Häusserstraße 3, 69115, Heidelberg, Germany
| | - Norbert Kučerka
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, 832 32, Bratislava, Slovakia
| | - Patrik Kula
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16610, Prague, Czech Republic
| | - Milla Kurki
- School of Pharmacy, University of Eastern Finland, 70211, Kuopio, Finland
| | | | - Anusha Lalitha
- Institut Charles Gerhardt Montpellier (UMR CNRS 5253), Université Montpellier, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, 69120, Heidelberg, Germany
- Department of Physics, University of Helsinki, FI-00014, Helsinki, Finland
| | - Jesper J Madsen
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, 33612, Tampa, FL, USA
- Center for Global Health and Infectious Diseases Research, Global and Planetary Health, College of Public Health, University of South Florida, 33612, Tampa, FL, USA
| | - Markus S Miettinen
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany
- Department of Chemistry, University of Bergen, 5007, Bergen, Norway
- Department of Informatics, Computational Biology Unit, University of Bergen, 5008, Bergen, Norway
| | - Cedric Mingham
- Hochschule Mannheim, University of Applied Sciences, 68163, Mannheim, Germany
| | - Luca Monticelli
- University of Lyon, CNRS, Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), F-69007, Lyon, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon, France
| | - Ricky Nencini
- University of Helsinki, Institute of Biotechnology, Helsinki, Finland
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00014, Helsinki, Finland
| | - Alexey M Nesterenko
- Department of Chemistry, University of Bergen, 5007, Bergen, Norway
- Department of Informatics, Computational Biology Unit, University of Bergen, 5008, Bergen, Norway
| | - Thomas J Piggot
- Chemistry, University of Southampton, Highfield, SO17 1BJ, Southampton, UK
| | - Ángel Piñeiro
- Department of Applied Physics, Faculty of Physics, University of Santiago de Compostela, E-15782, Santiago de Compostela, Spain
| | - Nathalie Reuter
- Department of Chemistry, University of Bergen, 5007, Bergen, Norway
- Department of Informatics, Computational Biology Unit, University of Bergen, 5008, Bergen, Norway
| | - Suman Samantray
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52428, Jülich, Germany
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Fabián Suárez-Lestón
- Center for Research in Biological Chemistry and Molecular Materials (CiQUS), Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain
- Department of Applied Physics, Faculty of Physics, University of Santiago de Compostela, E-15782, Santiago de Compostela, Spain
- MD.USE Innovations S.L., Edificio Emprendia, 15782, Santiago de Compostela, Spain
| | - Reza Talandashti
- Department of Chemistry, University of Bergen, 5007, Bergen, Norway
- Department of Informatics, Computational Biology Unit, University of Bergen, 5008, Bergen, Norway
| | - O H Samuli Ollila
- University of Helsinki, Institute of Biotechnology, Helsinki, Finland.
- VTT Technical Research Centre of Finland, Espoo, Finland.
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Madsen JJ, Yu W. Dynamic Nature of Staphylococcus aureus Type I Signal Peptidases. bioRxiv 2024:2024.01.23.576923. [PMID: 38328037 PMCID: PMC10849702 DOI: 10.1101/2024.01.23.576923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Molecular dynamics simulations are used to interrogate the dynamic nature of Staphylococcus aureus Type I signal peptidases, SpsA and SpsB, including the impact of the P29S mutation of SpsB. Fluctuations and plasticity- rigidity characteristics vary among the proteins, particularly in the extracellular domain. Intriguingly, the P29S mutation, which influences susceptibility to arylomycin antibiotics, affect the mechanically coupled motions in SpsB. The integrity of the active site is crucial for catalytic competency, and variations in sampled structural conformations among the proteins are consistent with diverse peptidase capabilities. We also explored the intricate interactions between the proteins and the model S. aureus membrane. It was observed that certain membrane-inserted residues in the loop around residue 50 (50s) and C-terminal loops, beyond the transmembrane domain, give rise to direct interactions with lipids in the bilayer membrane. Our findings are discussed in the context of functional knowledge about these signal peptidases, offering additional understanding of dynamic aspects relevant to some cellular processes with potential implications for drug targeting strategies.
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Affiliation(s)
- Jesper J. Madsen
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States of America
- Center for Global Health and Infectious Diseases Research, Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States of America
| | - Wenqi Yu
- Department of Molecular Biosciences, College of Arts and Sciences, University of South Florida, Tampa, Florida 33612, United States of America
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Giraldo J, Madsen JJ, Wang X, Wang L, Zhang C, Ye L. A 19F-qNMR-Guided Mathematical Model for G Protein-Coupled Receptor Signaling. Mol Pharmacol 2023; 105:54-62. [PMID: 37907352 PMCID: PMC10739436 DOI: 10.1124/molpharm.123.000754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/13/2023] [Accepted: 10/10/2023] [Indexed: 11/02/2023] Open
Abstract
G protein-coupled receptors (GPCRs) exhibit a wide range of pharmacological efficacies, yet the molecular mechanisms responsible for the differential efficacies in response to various ligands remain poorly understood. This lack of understanding has hindered the development of a solid foundation for establishing a mathematical model for signaling efficacy. However, recent progress has been made in delineating and quantifying receptor conformational states and associating function with these conformations. This progress has allowed us to construct a mathematical model for GPCR signaling efficacy that goes beyond the traditional ON/OFF binary switch model. In this study, we present a quantitative conformation-based mathematical model for GPCR signaling efficacy using the adenosine A2A receptor (A2AR) as a model system, under the guide of 19F quantitative nuclear magnetic resonance experiments. This model encompasses two signaling states, a fully activated state and a partially activated state, defined as being able to regulate the cognate Gα s nucleotide exchange with respective G protein recognition capacity. By quantifying the population distribution of each state, we can now in turn examine GPCR signaling efficacy. This advance provides a foundation for assessing GPCR signaling efficacy using a conformation-based mathematical model in response to ligand binding. SIGNIFICANCE STATEMENT: Mathematical models to describe signaling efficacy of GPCRs mostly suffer from considering only two states (ON/OFF). However, research indicates that a GPCR possesses multiple active-(like) states that can interact with Gαβγ independently, regulating varied nucleotide exchanges. With the guide of 19F-qNMR, the transitions among these states are quantified as a function of ligand and Gαβγ, serving as a foundation for a novel conformation-based mathematical signaling model.
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Affiliation(s)
- Jesús Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
| | - Jesper J Madsen
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
| | - Xudong Wang
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
| | - Lei Wang
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
| | - Cheng Zhang
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
| | - Libin Ye
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística and Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Bellaterra, Spain; Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental (J.G.), CIBERSAM, Spain; Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona (J.G.), Spain; Global and Planetary Health, College of Public Health (J.J.M.), Center for Global Health and Infectious Diseases Research, College of Public Health (J.J.M.), Department of Molecular Medicine, Morsani College of Medicine (J.J.M.), Department of Molecular Biosciences (X.W., L.Y.), University of South Florida, Tampa, Florida; Department of Pharmacology and Chemical Biology, University of PittsburghSchool of Medicine (L.W., C.Z.), University of Pittsburgh, Pittsburgh, Pennsylvania; and Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (L.Y.)
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7
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Madsen JJ, Petersen JE, Christensen DP, Hansen JB, Schwartz TW, Frimurer TM, Olsen OH. Deciphering specificity and cross-reactivity in tachykinin NK1 and NK2 receptors. J Biol Chem 2023; 299:105438. [PMID: 37944618 PMCID: PMC10724690 DOI: 10.1016/j.jbc.2023.105438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/26/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
The tachykinin receptors neurokinin 1 (NK1R) and neurokinin 2 (NK2R) are G protein-coupled receptors that bind preferentially to the natural peptide ligands substance P and neurokinin A, respectively, and have been targets for drug development. Despite sharing a common C-terminal sequence of Phe-X-Gly-Leu-Met-NH2 that helps direct biological function, the peptide ligands exhibit some degree of cross-reactivity toward each other's non-natural receptor. Here, we investigate the detailed structure-activity relationships of the ligand-bound receptor complexes that underlie both potent activation by the natural ligand and cross-reactivity. We find that the specificity and cross-reactivity of the peptide ligands can be explained by the interactions between the amino acids preceding the FxGLM consensus motif of the bound peptide ligand and two regions of the receptor: the β-hairpin of the extracellular loop 2 (ECL2) and a N-terminal segment leading into transmembrane helix 1. Positively charged sidechains of the ECL2 (R177 of NK1R and K180 of NK2R) are seen to play a vital role in the interaction. The N-terminal positions 1 to 3 of the peptide ligand are entirely dispensable. Mutated and chimeric receptor and ligand constructs neatly swap around ligand specificity as expected, validating the structure-activity hypotheses presented. These findings will help in developing improved agonists or antagonists for NK1R and NK2R.
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Affiliation(s)
- Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida, USA; Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, USA; Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Jacob E Petersen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Thue W Schwartz
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Thomas M Frimurer
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Ole H Olsen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
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8
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Javanainen M, Heftberger P, Madsen JJ, Miettinen MS, Pabst G, Ollila OHS. Quantitative Comparison against Experiments Reveals Imperfections in Force Fields' Descriptions of POPC-Cholesterol Interactions. J Chem Theory Comput 2023; 19:6342-6352. [PMID: 37616238 PMCID: PMC10536986 DOI: 10.1021/acs.jctc.3c00648] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Indexed: 08/26/2023]
Abstract
Cholesterol is a central building block in biomembranes, where it induces orientational order, slows diffusion, renders the membrane stiffer, and drives domain formation. Molecular dynamics (MD) simulations have played a crucial role in resolving these effects at the molecular level; yet, it has recently become evident that different MD force fields predict quantitatively different behavior. Although easily neglected, identifying such limitations is increasingly important as the field rapidly progresses toward simulations of complex membranes mimicking the in vivo conditions: pertinent multicomponent simulations must capture accurately the interactions between their fundamental building blocks, such as phospholipids and cholesterol. Here, we define quantitative quality measures for simulations of binary lipid mixtures in membranes against the C-H bond order parameters and lateral diffusion coefficients from NMR spectroscopy as well as the form factors from X-ray scattering. Based on these measures, we perform a systematic evaluation of the ability of commonly used force fields to describe the structure and dynamics of binary mixtures of palmitoyloleoylphosphatidylcholine (POPC) and cholesterol. None of the tested force fields clearly outperforms the others across the tested properties and conditions. Still, the Slipids parameters provide the best overall performance in our tests, especially when dynamic properties are included in the evaluation. The quality evaluation metrics introduced in this work will, particularly, foster future force field development and refinement for multicomponent membranes using automated approaches.
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Affiliation(s)
- Matti Javanainen
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences of the Czech Republic, 16000 Prague 6, Czech Republic
- Institute
of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
| | - Peter Heftberger
- Biophysics,
Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
| | - Jesper J. Madsen
- Global
and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
- Center
for Global Health and Infectious Diseases Research, College of Public
Health, University of South Florida, Tampa, Florida 33612, United States
- Department
of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
| | - Markus S. Miettinen
- Fachbereich
Physik, Freie Universität Berlin, 14195 Berlin, Germany
- Department
of Chemistry, University of Bergen, 5007 Bergen, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, 5008 Bergen, Norway
| | - Georg Pabst
- Biophysics,
Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Field of Excellence
BioHealth—University of Graz, 8010 Graz, Austria
| | - O. H. Samuli Ollila
- Institute
of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
- VTT Technical Research Centre of Finland, 02150 Espoo, Finland
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9
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Yun Wen C, Madsen JJ, Lyna Luo Y. Efficient coarse-grained simulations of multiple Piezo channels in flat membrane and vesicles. Biophys J 2023; 122:374a. [PMID: 36783900 DOI: 10.1016/j.bpj.2022.11.2059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Chen Yun Wen
- Western University of Health Sciences, Pomona, CA, USA
| | - Jesper J Madsen
- Global Health and Infectious Diseases Research, University of South Florida, Tampa, FL, USA
| | - Yun Lyna Luo
- Department of Pharmaceutical Sciences, Western University of Health Sciences, Pomona, CA, USA
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10
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Madsen JJ, Rossman JS. Cholesterol and M2 Rendezvous in Budding and Scission of Influenza A Virus. Subcell Biochem 2023; 106:441-459. [PMID: 38159237 DOI: 10.1007/978-3-031-40086-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The cholesterol of the host cell plasma membrane and viral M2 protein plays a crucial role in multiple stages of infection and replication of the influenza A virus. Cholesterol is required for the formation of heterogeneous membrane microdomains (or rafts) in the budozone of the host cell that serves as assembly sites for the viral components. The raft microstructures act as scaffolds for several proteins. Cholesterol may further contribute to the mechanical forces necessary for membrane scission in the last stage of budding and help to maintain the stability of the virus envelope. The M2 protein has been shown to cause membrane scission in model systems by promoting the formation of curved lipid bilayer structures that, in turn, can lead to membrane vesicles budding off or scission intermediates. Membrane remodeling by M2 is intimately linked with cholesterol as it affects local lipid composition, fluidity, and stability of the membrane. Thus, both cholesterol and M2 protein contribute to the efficient and proper release of newly formed influenza viruses from the virus-infected cells.
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Affiliation(s)
- Jesper J Madsen
- Global and Planetary Health, Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, FL, USA.
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
| | - Jeremy S Rossman
- School of Biosciences, University of Kent, Canterbury, Kent, UK
- Research-Aid Networks, Chicago, IL, USA
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11
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Madsen JJ, Ye L, Frimurer TM, Olsen OH. Mechanistic basis of GPCR activation explored by ensemble refinement of crystallographic structures. Protein Sci 2022; 31:e4456. [PMID: 36134696 PMCID: PMC9601807 DOI: 10.1002/pro.4456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 08/09/2022] [Accepted: 09/16/2022] [Indexed: 12/05/2022]
Abstract
G protein‐coupled receptors (GPCRs) are important drug targets characterized by a canonical seven transmembrane (TM) helix architecture. Recent advances in X‐ray crystallography and cryo‐EM have resulted in a wealth of GPCR structures that have been used in drug design and formed the basis for mechanistic activation hypotheses. Here, ensemble refinement (ER) of crystallographic structures is applied to explore the impact of binding of agonists and antagonist/inverse agonists to selected structures of cannabinoid receptor 1 (CB1R), β2 adrenergic receptor (β2AR), and A2A adenosine receptor (A2AAR). To assess the conformational flexibility and its role in GPCR activation, hydrogen bond (H‐bond) networks are analyzed by calculating and comparing H‐bond propensities. Mapping pairwise propensity differences between agonist‐ and inverse agonist/antagonist‐bound structures for CB1R and β2AR shows that agonist binding destabilizes H‐bonds in the intracellular parts of TM 5–7, forming the G protein binding cavity, while H‐bonds of the extracellular segment of TMs surrounding the orthosteric site are conversely stabilized. Certain class A GPCRs, for example, A2AAR, bind an allosteric sodium ion that negatively modulates agonist binding. The impact of sodium‐excluding mutants (D522.50N, S913.39A) of A2AAR on agonist binding is examined by applying ER analysis to structures of wildtype and the two mutants in complex with a full agonist. While S913.39A exhibits normal activity, D522.50N quenches the downstream signaling. The mainchain H‐bond pattern of the latter is stabilized in the intracellular part of TM 7 containing the NPxxY motif, indicating that an induced rigidity of the mutation prevents conformational selection of G proteins resulting in receptor inactivation.
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Affiliation(s)
- Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Libin Ye
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA.,H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA
| | - Thomas M Frimurer
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Blegdamsvej 3b, Copenhagen N, Denmark
| | - Ole H Olsen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Blegdamsvej 3b, Copenhagen N, Denmark
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12
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Ye L, Wang X, McFarland A, Madsen JJ. 19F NMR: A promising tool for dynamic conformational studies of G protein-coupled receptors. Structure 2022; 30:1372-1384. [PMID: 36130592 DOI: 10.1016/j.str.2022.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 07/31/2022] [Accepted: 08/23/2022] [Indexed: 10/14/2022]
Abstract
Advances in X-ray crystallography and cryoelectron microscopy enabled unprecedented insights into the activation processes of G protein-coupled receptors (GPCRs). However, these static receptor structures provide limited information about dynamics and conformational transitions that play pivotal roles in mediating signaling diversity through the multifaceted interactions between ligands, receptors, and transducers. Developing NMR approaches to probe the dynamics of conformational transitions will push the frontier of receptor science toward a more comprehensive understanding of these signaling processes. Although much progress has been made during the last decades, it remains challenging to delineate receptor conformational states and interrogate the functions of the individual states at a quantitative level. Here we cover the progress of 19F NMR applications in GPCR conformational and dynamic studies during the past 20 years. Current challenges and limitations of 19F NMR for studying GPCR dynamics are also discussed, along with experimental strategies that will drive this field forward.
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Affiliation(s)
- Libin Ye
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA; H. Lee Moffitt Cancer Center & Research Institute, 12902 USF Magnolia Drive, Tampa, FL 33612, USA.
| | - Xudong Wang
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Aidan McFarland
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL 33612, USA; Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
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13
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Wang X, Bushra N, Muschol M, Madsen JJ, Ye L. An in-membrane NMR spectroscopic approach probing native ligand-GPCR interaction. Int J Biol Macromol 2022; 206:911-916. [PMID: 35318080 DOI: 10.1016/j.ijbiomac.2022.03.099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 01/02/2023]
Abstract
Conventional approaches to study ligand-receptor interactions using solution-state NMR often involve laborious sample preparation, isotopic labeling, and receptor reconstitution. Each of these steps remains challenging for membrane proteins such as G protein-coupled receptors (GPCRs). Here we introduce a combinational approach integrating NMR and homogenized membrane nano-discs preparation to characterize the ligand-GPCR interactions. The approach will have a great potential for drug screening as it benefits from minimal receptor preparation, minimizing non-specific binding. In addition, the approach maintains receptor structural heterogeneity essential for functional diversity, making it feasible for probing a more reliable ligand-GPCR interaction that is vital for faithful ligand discovery.
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Affiliation(s)
- Xudong Wang
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Nabila Bushra
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - Martin Muschol
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL 33612, USA; Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Libin Ye
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA; H. Lee Moffitt Cancer Center & Research Institute, 12902 USF Magnolia Drive, Tampa, FL 33612, USA.
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14
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Sorensen AB, Greisen PJ, Madsen JJ, Lund J, Andersen G, Wulff-Larsen PG, Pedersen AA, Gandhi PS, Overgaard MT, Østergaard H, Olsen OH. A systematic approach for evaluating the role of surface-exposed loops in trypsin-like serine proteases applied to the 170 loop in coagulation factor VIIa. Sci Rep 2022; 12:3747. [PMID: 35260627 PMCID: PMC8904457 DOI: 10.1038/s41598-022-07620-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/14/2022] [Indexed: 12/27/2022] Open
Abstract
Proteases play a major role in many vital physiological processes. Trypsin-like serine proteases (TLPs), in particular, are paramount in proteolytic cascade systems such as blood coagulation and complement activation. The structural topology of TLPs is highly conserved, with the trypsin fold comprising two β-barrels connected by a number of variable surface-exposed loops that provide a surprising capacity for functional diversity and substrate specificity. To expand our understanding of the roles these loops play in substrate and co-factor interactions, we employ a systematic methodology akin to the natural truncations and insertions observed through evolution of TLPs. The approach explores a larger deletion space than classical random or directed mutagenesis. Using FVIIa as a model system, deletions of 1–7 amino acids through the surface exposed 170 loop, a vital allosteric regulator, was introduced. All variants were extensively evaluated by established functional assays and computational loop modelling with Rosetta. The approach revealed detailed structural and functional insights recapitulation and expanding on the main findings in relation to 170 loop functions elucidated over several decades using more cumbersome crystallization and single deletion/mutation methodologies. The larger deletion space was key in capturing the most active variant, which unexpectedly had a six-amino acid truncation. This variant would have remained undiscovered if only 2–3 deletions were considered, supporting the usefulness of the methodology in general protease engineering approaches. Our findings shed further light on the complex role that surface-exposed loops play in TLP function and supports the important role of loop length in the regulation and fine-tunning of enzymatic function throughout evolution.
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Affiliation(s)
- Anders B Sorensen
- Global Research, Novo Nordisk A/S, 2760, Måløv, Denmark.,Department of Chemistry and Bioscience, Aalborg University, 9220, Ålborg, Denmark
| | | | - Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL, 33612, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Jacob Lund
- Global Research, Novo Nordisk A/S, 2760, Måløv, Denmark
| | - Gorm Andersen
- Global Research, Novo Nordisk A/S, 2760, Måløv, Denmark
| | | | | | | | - Michael T Overgaard
- Department of Chemistry and Bioscience, Aalborg University, 9220, Ålborg, Denmark
| | | | - Ole H Olsen
- Global Research, Novo Nordisk A/S, 2760, Måløv, Denmark. .,Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark.
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15
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Bacle A, Buslaev P, Garcia-Fandino R, Favela-Rosales F, Mendes Ferreira T, Fuchs PFJ, Gushchin I, Javanainen M, Kiirikki AM, Madsen JJ, Melcr J, Milán Rodríguez P, Miettinen MS, Ollila OHS, Papadopoulos CG, Peón A, Piggot TJ, Piñeiro Á, Virtanen SI. Inverse Conformational Selection in Lipid-Protein Binding. J Am Chem Soc 2021; 143:13701-13709. [PMID: 34465095 DOI: 10.1021/jacs.1c05549] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups exchange between a few rigid structures, or fluctuate freely across a practically continuous spectrum of conformations? Here, we combine solid-state NMR experiments and molecular dynamics simulations from the NMRlipids Project to resolve the conformational ensembles of headgroups of four key lipid types in various biologically relevant conditions. We find that lipid headgroups sample a wide range of overlapping conformations in both neutral and charged cellular membranes, and that differences in the headgroup chemistry manifest only in probability distributions of conformations. Furthermore, the analysis of 894 protein-bound lipid structures from the Protein Data Bank suggests that lipids can bind to proteins in a wide range of conformations, which are not limited by the headgroup chemistry. We propose that lipids can select a suitable headgroup conformation from the wide range available to them to fit the various binding sites in proteins. The proposed inverse conformational selection model will extend also to lipid binding to targets other than proteins, such as drugs, RNA, and viruses.
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Affiliation(s)
- Amélie Bacle
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1 rue Georges Bonnet, Poitiers 86000, France
| | - Pavel Buslaev
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä 40014, Finland.,Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Rebeca Garcia-Fandino
- Center for Research in Biological Chemistry and Molecular Materials (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain.,CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Fernando Favela-Rosales
- Departamento de Ciencias Básicas, Tecnológico Nacional de México - ITS Zacatecas Occidente, Sombrerete, Zacatecas 99102, México
| | - Tiago Mendes Ferreira
- NMR group - Institute for Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Patrick F J Fuchs
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France.,UFR Sciences du Vivant, Université de Paris, Paris 75013, France
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, Prague CZ-16610, Czech Republic
| | - Anne M Kiirikki
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Jesper J Madsen
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.,Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
| | - Josef Melcr
- Groningen Biomolecular Sciences and Biotechnology Institute and The Zernike Institute for Advanced Materials, University of Groningen, Groningen9747 AG, The Netherlands
| | - Paula Milán Rodríguez
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France
| | - Markus S Miettinen
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - O H Samuli Ollila
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Chris G Papadopoulos
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette 91198, France
| | - Antonio Peón
- CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Thomas J Piggot
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Ángel Piñeiro
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain
| | - Salla I Virtanen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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16
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Abstract
In the life sciences, including hemostasis and thrombosis, methods of structural biology have become indispensable tools for shedding light on underlying mechanisms that govern complex biological processes. Advancements of the relatively young field of computational biology have matured to a point where it is increasingly recognized as trustworthy and useful, in part due to their high space–time resolution that is unparalleled by most experimental techniques to date. In concert with biochemical and biophysical approaches, computational studies have therefore proven time and again in recent years to be key assets in building or suggesting structural models for membrane-bound forms of coagulation factors and their supramolecular complexes on membrane surfaces where they are activated. Such endeavors and the proposed models arising from them are of fundamental importance in describing and understanding the molecular basis of hemostasis under both health and disease conditions. We summarize the body of work done in this important area of research to drive forward both experimental and computational studies toward new discoveries and potential future therapeutic strategies.
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Affiliation(s)
- Y Zenmei Ohkubo
- Department of Bioinformatics, School of Life and Natural Sciences, Abdullah Gül University, Kayseri, Turkey
| | - Jesper J Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida, United States
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17
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Madsen JJ, Olsen OH. Conformational Plasticity-Rigidity Axis of the Coagulation Factor VII Zymogen Elucidated by Atomistic Simulations of the N-Terminally Truncated Factor VIIa Protease Domain. Biomolecules 2021; 11:549. [PMID: 33917935 PMCID: PMC8068379 DOI: 10.3390/biom11040549] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 11/22/2022] Open
Abstract
The vast majority of coagulation factor VII (FVII), a trypsin-like protease, circulates as the inactive zymogen. Activated FVII (FVIIa) is formed upon proteolytic activation of FVII, where it remains in a zymogen-like state and it is fully activated only when bound to tissue factor (TF). The catalytic domains of trypsin-like proteases adopt strikingly similar structures in their fully active forms. However, the dynamics and structures of the available corresponding zymogens reveal remarkable conformational plasticity of the protease domain prior to activation in many cases. Exactly how ligands and cofactors modulate the conformational dynamics and function of these proteases is not entirely understood. Here, we employ atomistic simulations of FVIIa (and variants hereof, including a TF-independent variant and N-terminally truncated variants) to provide fundamental insights with atomistic resolution into the plasticity-rigidity interplay of the protease domain conformations that appears to govern the functional response to proteolytic and allosteric activation. We argue that these findings are relevant to the FVII zymogen, whose structure has remained elusive despite substantial efforts. Our results shed light on the nature of FVII and demonstrate how conformational dynamics has played a crucial role in the evolutionary adaptation of regulatory mechanisms that were not present in the ancestral trypsin. Exploiting this knowledge could lead to engineering of protease variants for use as next-generation hemostatic therapeutics.
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Affiliation(s)
- Jesper J. Madsen
- Global and Planetary Health, College of Public Health, University of South Florida, Tampa, FL 33612, USA
| | - Ole H. Olsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology, University of Copenhagen, Blegdamsvej 3b, DK-2200 Copenhagen, Denmark
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18
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Wang X, Zhao W, Al-Abdul-Wahid S, Lu Y, Cheng T, Madsen JJ, Ye L. Trifluorinated Keto-Enol Tautomeric Switch in Probing Domain Rotation of a G Protein-Coupled Receptor. Bioconjug Chem 2020; 32:99-105. [PMID: 33377784 DOI: 10.1021/acs.bioconjchem.0c00670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Conformational dynamics and transitions of biologically active molecules are pivotal for understanding the physiological responses they elicit. In the case of receptor activation, there are major implications elucidating disease mechanisms and drug discovery innovation. Yet, incorporation of these factors into drug screening systems remains challenging in part due to the lack of suitable approaches to include them. Here, we present a novel strategy to probe the GPCR domain rotation by utilizing the 19fluorine signal variability of a trifluorinated keto-enol (TFKE) chemical equilibrium. The method takes advantage of the high sensitivity of the TFKE tautomerism toward microenvironmental changes resulting from receptor conformational transitions upon ligand binding. We validated the method using the adenosine A2AR receptor as a model system in which the TFKE was attached to two sites exhibiting opposing motions upon ligand binding, namely, V229C6.31 on transmembrane domain VI (TM6) and A289C7.54 on TM7. Our results demonstrated that the TFKE switch was an excellent reporter for the domain rotation and could be used to study the conformational transition and dynamics of relative domain motions. Although further studies are needed in order to establish a quantitative relationship between the rotational angle and the population distribution of different components in a particular system, the research presented here provides a foundation for its application in studying receptor domain rotation and dynamics, which could be useful in drug screening efforts.
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Affiliation(s)
- Xudong Wang
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida 33620, United States
| | - Wenjie Zhao
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida 33620, United States
| | - Sameer Al-Abdul-Wahid
- Nuclear Magnetic Resonance Center, University of Guelph, Guelph, Ontario NIG2W1, Canada
| | - Yiming Lu
- Institute of Functional Nano&Soft Materials, Soochow University, Dushu-Lake Campus, Suzhou, Jiangsu 215123, China
| | - Tao Cheng
- Institute of Functional Nano&Soft Materials, Soochow University, Dushu-Lake Campus, Suzhou, Jiangsu 215123, China
| | - Jesper J Madsen
- Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
| | - Libin Ye
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida 33620, United States.,H. Lee Moffitt Cancer Center & Research Institute, 12902 USF Magnolia Drive, Tampa, Florida 33612, United States
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19
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Martyna A, Bahsoun B, Madsen JJ, Jackson FSJS, Badham MD, Voth GA, Rossman JS. Cholesterol Alters the Orientation and Activity of the Influenza Virus M2 Amphipathic Helix in the Membrane. J Phys Chem B 2020; 124:6738-6747. [PMID: 32644803 PMCID: PMC7515559 DOI: 10.1021/acs.jpcb.0c03331] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
The
influenza virus M2 amphipathic helix (M2AH) alters membrane
curvature in a cholesterol-dependent manner, mediating viral membrane
scission during influenza virus budding. Here, we have investigated
the biophysical effects of cholesterol on the ability of an M2AH peptide
to manipulate membrane properties. We see that the ability of the
M2AH to interact with membranes and form an α-helix is independent
of membrane cholesterol concentration; however, cholesterol affects
the angle of the M2AH peptide within the membrane. This change in
membrane orientation affects the ability of the M2AH to alter lipid
order. In low-cholesterol membranes, the M2AH is inserted near the
level of the lipid head groups, increasing lipid order, which may
contribute to generation of the membrane curvature. As the cholesterol
content increases, the M2AH insertion becomes flatter and slightly
deeper in the membrane below the lipid headgroups, where the polar
face can continue to interact with the headgroups while the hydrophobic
face binds cholesterol. This changed orientation minimizes lipid packing
defects and lipid order changes, likely reducing the generation of
membrane curvature. Thus, cholesterol regulates M2 membrane scission
by precisely modulating M2AH positioning within the membrane. This
has implications for the understanding of many of amphipathic-helix-driven
cellular budding processes that occur in specific lipid environments.
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Affiliation(s)
- Agnieszka Martyna
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
| | - Basma Bahsoun
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
| | - Jesper J Madsen
- Department of Chemistry and Chicago Center for Theoretical Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.,James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States.,Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States.,Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
| | | | - Matthew D Badham
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
| | - Gregory A Voth
- Department of Chemistry and Chicago Center for Theoretical Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.,James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States.,Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jeremy S Rossman
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, United Kingdom
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20
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Tjørnelund HD, Madsen JJ, Peters GHJ. Water-Intake and Water-Molecule Paths to the Active Site of Secretory Phospholipase A 2 Studied Using MD Simulations and the Tracking Tool AQUA-DUCT. J Phys Chem B 2020; 124:1881-1891. [PMID: 32064878 DOI: 10.1021/acs.jpcb.9b10837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Secretory phospholipases A2 (sPLA2s) are a subclass of enzymes that catalyze the hydrolysis at the sn-2 position of glycerophospholipids, producing free fatty acids and lysophospholipids. In this study, different phospholipids with structural modifications close to the scissile sn-2 ester bond were studied to determine the effect of the structural changes on the formation of the Michaelis-Menten complex and the water entry/exit pathways using molecular dynamics simulations and the computational tracking tool AQUA-DUCT. Structural modifications include methylation, dehydrogenation, and polarization close to the sn-2 scissile bond. We found that all water molecules reaching the active site of sPLA2-IIA pass by the aromatic residues Phe5 and Tyr51 and enter the active site through an active-site cleft. The relative amount of water available for the enzymatic reaction of the different phospholipid-sPLA2 complexes was determined together with the distance between key atoms in the catalytic machinery. The results showed that (Z)-unsaturated phospholipid is a good substrate for sPLA2-IIA. The computational results are in good agreement with previously reported experimental data on the ability of sPLA2-IIA to hydrolyze liposomes made from the different phospholipids, and the results provide new insights into the necessary active-site solvation of the Michaelis-Menten complex and can pave the road for rational design in engineering applications.
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Affiliation(s)
- Helena D Tjørnelund
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Jesper J Madsen
- Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida 33620, United States
| | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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21
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Antila H, Buslaev P, Favela-Rosales F, Ferreira TM, Gushchin I, Javanainen M, Kav B, Madsen JJ, Melcr J, Miettinen MS, Määttä J, Nencini R, Ollila OHS, Piggot TJ. Headgroup Structure and Cation Binding in Phosphatidylserine Lipid Bilayers. J Phys Chem B 2019; 123:9066-9079. [DOI: 10.1021/acs.jpcb.9b06091] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Hanne Antila
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Pavel Buslaev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141701 Russia
| | - Fernando Favela-Rosales
- Departamento de Investigación, Tecnológico Nacional de México, Campus Zacatecas Occidente, C. P. 99102 Zacatecas, México
| | - Tiago M. Ferreira
- NMR Group - Institute for Physics, Martin-Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141701 Russia
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16610 Prague 6, Czech Republic
| | - Batuhan Kav
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Jesper J. Madsen
- Department of Chemistry, The University of Chicago, 60637 Chicago, Illinois, United States of America
- Department of Global Health, College of Public Health, University of South Florida, 33612 Tampa, Florida, United States of America
| | - Josef Melcr
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16610 Prague 6, Czech Republic
- Groningen Biomolecular Sciences and Biotechnology Institute and The Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Markus S. Miettinen
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Jukka Määttä
- Department of Chemistry and Materials Science, Aalto University, 00076 Espoo, Finland
| | - Ricky Nencini
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16610 Prague 6, Czech Republic
| | - O. H. Samuli Ollila
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16610 Prague 6, Czech Republic
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Thomas J. Piggot
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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22
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Sorensen AB, Madsen JJ, Frimurer TM, Overgaard MT, Gandhi PS, Persson E, Olsen OH. Allostery in Coagulation Factor VIIa Revealed by Ensemble Refinement of Crystallographic Structures. Biophys J 2019; 116:1823-1835. [PMID: 31003762 DOI: 10.1016/j.bpj.2019.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 11/29/2022] Open
Abstract
A critical step in injury-induced initiation of blood coagulation is the formation of the complex between the trypsin-like protease coagulation factor VIIa (FVIIa) and its cofactor tissue factor (TF), which converts FVIIa from an intrinsically poor enzyme to an active protease capable of activating zymogens of downstream coagulation proteases. Unlike its constitutively active ancestor trypsin, FVIIa is allosterically activated (by TF). Here, ensemble refinement of crystallographic structures, which uses multiple copies of the entire structure as a means of representing structural flexibility, is applied to explore the impacts of inhibitor binding to trypsin and FVIIa, as well as cofactor binding to FVIIa. To assess the conformational flexibility and its role in allosteric pathways in these proteases, main-chain hydrogen bond networks are analyzed by calculating the hydrogen-bond propensity. Mapping pairwise propensity differences between relevant structures shows that binding of the inhibitor benzamidine to trypsin has a minor influence on the protease flexibility. For FVIIa, in contrast, the protease domain is "locked" into the catalytically competent trypsin-like configuration upon benzamidine binding as indicated by the stabilization of key structural features: the nonprime binding cleft and the oxyanion hole are stabilized, and the effect propagates from the active site region to the calcium-binding site and to the vicinity of the disulphide bridge connecting with the light chain. TF binding to FVIIa furthermore results in stabilization of the 170 loop, which in turn propagates an allosteric signal from the TF-binding region to the active site. Analyses of disulphide bridge energy and flexibility reflect the striking stability difference between the unregulated enzyme and the allosterically activated form after inhibitor or cofactor binding. The ensemble refinement analyses show directly, for the first time to our knowledge, whole-domain structural footprints of TF-induced allosteric networks present in x-ray crystallographic structures of FVIIa, which previously only have been hypothesized or indirectly inferred.
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Affiliation(s)
- Anders B Sorensen
- Global Research, Novo Nordisk A/S, Måløv, Denmark; Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark; Protein Research, Evaxion Biotech, Copenhagen, Denmark
| | - Jesper J Madsen
- Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida
| | - Thomas M Frimurer
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Michael T Overgaard
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | | | - Egon Persson
- Global Research, Novo Nordisk A/S, Måløv, Denmark
| | - Ole H Olsen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
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23
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Klitgaard K, Højgaard J, Isbrand A, Madsen JJ, Thorup K, Bødker R. Screening for multiple tick-borne pathogens in Ixodes ricinus ticks from birds in Denmark during spring and autumn migration seasons. Ticks Tick Borne Dis 2019; 10:546-552. [DOI: 10.1016/j.ttbdis.2019.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 12/15/2022]
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24
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Pak AJ, Dannenhoffer-Lafage T, Madsen JJ, Voth GA. Systematic Coarse-Grained Lipid Force Fields with Semiexplicit Solvation via Virtual Sites. J Chem Theory Comput 2019; 15:2087-2100. [PMID: 30702887 PMCID: PMC6416712 DOI: 10.1021/acs.jctc.8b01033] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
Despite
the central role of lipids in many biophysical functions,
the molecular mechanisms that dictate macroscopic lipid behavior remain
elusive to both experimental and computational approaches. As such,
there has been much interest in the development of low-resolution,
implicit-solvent coarse-grained (CG) models to dynamically simulate
biologically relevant spatiotemporal scales with molecular fidelity.
However, in the absence of solvent, a key challenge for CG models
is to faithfully emulate solvent-mediated forces, which include both
hydrophilic and hydrophobic interactions that drive lipid aggregation
and self-assembly. In this work, we provide a new methodological framework
to incorporate semiexplicit solvent effects through the use of virtual
CG particles, which represent structural features of the solvent-lipid
interface. To do so, we leverage two systematic coarse-graining approaches,
multiscale coarse-graining (MS-CG) and relative entropy minimization
(REM), in a hybrid fashion to construct our virtual-site CG (VCG)
models. As a proof-of-concept, we focus our efforts on two lipid species,
1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and
1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC),
which adopt a liquid-disordered and gel phase, respectively, at room
temperature. Through our analysis, we also present, to our knowledge,
the first direct comparison between the MS-CG and REM methods for
a complex biomolecule and highlight each of their strengths and weaknesses.
We further demonstrate that VCG models recapitulate the rich biophysics
of lipids, which enable self-assembly, morphological diversity, and
multiple phases. Our findings suggest that the VCG framework is a
powerful approach for investigation into macromolecular biophysics.
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Affiliation(s)
- Alexander J Pak
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , United States
| | | | - Jesper J Madsen
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Gregory A Voth
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , United States
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25
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Madsen JJ, Persson E, Olsen OH. Evolutionary conservation of the allosteric activation of factor VIIa by tissue factor in lamprey: comment. J Thromb Haemost 2018; 16:1450-1454. [PMID: 29733494 DOI: 10.1111/jth.14142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Indexed: 11/28/2022]
Affiliation(s)
- J J Madsen
- Department of Chemistry, University of Chicago, Chicago, IL, USA
| | - E Persson
- Hemophilia Biology, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark
| | - O H Olsen
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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26
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Sønderby P, Rinnan Å, Madsen JJ, Harris P, Bukrinski JT, Peters GHJ. Small-Angle X-ray Scattering Data in Combination with RosettaDock Improves the Docking Energy Landscape. J Chem Inf Model 2017; 57:2463-2475. [DOI: 10.1021/acs.jcim.6b00789] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Pernille Sønderby
- Department
of Chemistry, Technical University of Denmark, DK-2800 Kongens
Lyngby, Denmark
| | - Åsmund Rinnan
- Department
of Food Science, Faculty of Science, University of Copenhagen, DK-1958 Frederiksberg C, Denmark
| | - Jesper J. Madsen
- Department
of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Pernille Harris
- Department
of Chemistry, Technical University of Denmark, DK-2800 Kongens
Lyngby, Denmark
| | | | - Günther H. J. Peters
- Department
of Chemistry, Technical University of Denmark, DK-2800 Kongens
Lyngby, Denmark
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27
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Liang R, Swanson JMJ, Madsen JJ, Hong M, DeGrado WF, Voth GA. Acid activation mechanism of the influenza A M2 proton channel. Proc Natl Acad Sci U S A 2016; 113:E6955-E6964. [PMID: 27791184 PMCID: PMC5111692 DOI: 10.1073/pnas.1615471113] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The homotetrameric influenza A M2 channel (AM2) is an acid-activated proton channel responsible for the acidification of the influenza virus interior, an important step in the viral lifecycle. Four histidine residues (His37) in the center of the channel act as a pH sensor and proton selectivity filter. Despite intense study, the pH-dependent activation mechanism of the AM2 channel has to date not been completely understood at a molecular level. Herein we have used multiscale computer simulations to characterize (with explicit proton transport free energy profiles and their associated calculated conductances) the activation mechanism of AM2. All proton transfer steps involved in proton diffusion through the channel, including the protonation/deprotonation of His37, are explicitly considered using classical, quantum, and reactive molecular dynamics methods. The asymmetry of the proton transport free energy profile under high-pH conditions qualitatively explains the rectification behavior of AM2 (i.e., why the inward proton flux is allowed when the pH is low in viral exterior and high in viral interior, but outward proton flux is prohibited when the pH gradient is reversed). Also, in agreement with electrophysiological results, our simulations indicate that the C-terminal amphipathic helix does not significantly change the proton conduction mechanism in the AM2 transmembrane domain; the four transmembrane helices flanking the channel lumen alone seem to determine the proton conduction mechanism.
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Affiliation(s)
- Ruibin Liang
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- James Franck Institute, The University of Chicago, Chicago, IL 60637
| | - Jessica M J Swanson
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- James Franck Institute, The University of Chicago, Chicago, IL 60637
| | - Jesper J Madsen
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- James Franck Institute, The University of Chicago, Chicago, IL 60637
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - William F DeGrado
- Department of Pharmaceutical Chemistry, University of San Francisco, San Francisco, CA 94158
| | - Gregory A Voth
- Department of Chemistry, The University of Chicago, Chicago, IL 60637;
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637
- James Franck Institute, The University of Chicago, Chicago, IL 60637
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28
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Madsen JJ, Fristrup P, Peters GH. Theoretical Assessment of Fluorinated Phospholipids in the Design of Liposomal Drug-Delivery Systems. J Phys Chem B 2016; 120:9661-71. [DOI: 10.1021/acs.jpcb.6b07206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Jesper J. Madsen
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Peter Fristrup
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Günther H. Peters
- Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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29
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Sorensen AB, Madsen JJ, Svensson LA, Pedersen AA, Østergaard H, Overgaard MT, Olsen OH, Gandhi PS. Molecular Basis of Enhanced Activity in Factor VIIa-Trypsin Variants Conveys Insights into Tissue Factor-mediated Allosteric Regulation of Factor VIIa Activity. J Biol Chem 2015; 291:4671-83. [PMID: 26694616 DOI: 10.1074/jbc.m115.698613] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Indexed: 11/06/2022] Open
Abstract
The complex of coagulation factor VIIa (FVIIa), a trypsin-like serine protease, and membrane-bound tissue factor (TF) initiates blood coagulation upon vascular injury. Binding of TF to FVIIa promotes allosteric conformational changes in the FVIIa protease domain and improves its catalytic properties. Extensive studies have revealed two putative pathways for this allosteric communication. Here we provide further details of this allosteric communication by investigating FVIIa loop swap variants containing the 170 loop of trypsin that display TF-independent enhanced activity. Using x-ray crystallography, we show that the introduced 170 loop from trypsin directly interacts with the FVIIa active site, stabilizing segment 215-217 and activation loop 3, leading to enhanced activity. Molecular dynamics simulations and novel fluorescence quenching studies support that segment 215-217 conformation is pivotal to the enhanced activity of the FVIIa variants. We speculate that the allosteric regulation of FVIIa activity by TF binding follows a similar path in conjunction with protease domain N terminus insertion, suggesting a more complete molecular basis of TF-mediated allosteric enhancement of FVIIa activity.
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Affiliation(s)
- Anders B Sorensen
- From Global Research, Novo Nordisk A/S, 2760 Måløv, Denmark, Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark, and
| | - Jesper J Madsen
- From Global Research, Novo Nordisk A/S, 2760 Måløv, Denmark, Department of Chemistry, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | | | | | | | - Michael T Overgaard
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark, and
| | - Ole H Olsen
- From Global Research, Novo Nordisk A/S, 2760 Måløv, Denmark
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30
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Madsen JJ, Ohkubo YZ, Peters GH, Faber JH, Tajkhorshid E, Olsen OH. Membrane Interaction of the Factor VIIIa Discoidin Domains in Atomistic Detail. Biochemistry 2015; 54:6123-31. [PMID: 26346528 DOI: 10.1021/acs.biochem.5b00417] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A recently developed membrane-mimetic model was applied to study membrane interaction and binding of the two anchoring C2-like discoidin domains of human coagulation factor VIIIa (FVIIIa), the C1 and C2 domains. Both individual domains, FVIII C1 and FVIII C2, were observed to bind the phospholipid membrane by partial or full insertion of their extruding loops (the spikes). However, the two domains adopted different molecular orientations in their membrane-bound states; FVIII C2 roughly was positioned normal to the membrane plane, while FVIII C1 displayed a multitude of tilted orientations. The results indicate that FVIII C1 may be important in modulating the orientation of the FVIIIa molecule to optimize the interaction with FIXa, which is anchored to the membrane via its γ-carboxyglutamic acid-rich (Gla) domain. Additionally, a structural change was observed in FVIII C1 in the coiled main chain leading the first spike. A tight interaction with one lipid per domain, similar to what has been suggested for the homologous FVa C2, is characterized. Finally, we rationalize known FVIII antibody epitopes and the scarcity of documented hemophilic missense mutations related to improper membrane binding of FVIIIa, based on the prevalent nonspecificity of ionic interactions in the simulated membrane-bound states of FVIII C1 and FVIII C2.
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Affiliation(s)
- Jesper J Madsen
- Global Research, Novo Nordisk A/S , DK-2760 Måløv, Denmark.,Department of Chemistry, Technical University of Denmark , DK-2800 Kgs. Lyngby, Denmark
| | | | - Günther H Peters
- Department of Chemistry, Technical University of Denmark , DK-2800 Kgs. Lyngby, Denmark
| | - Johan H Faber
- Global Research, Novo Nordisk A/S , DK-2760 Måløv, Denmark
| | | | - Ole H Olsen
- Global Research, Novo Nordisk A/S , DK-2760 Måløv, Denmark
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31
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van den Biggelaar M, Madsen JJ, Faber JH, Zuurveld MG, van der Zwaan C, Olsen OH, Stennicke HR, Mertens K, Meijer AB. Factor VIII Interacts with the Endocytic Receptor Low-density Lipoprotein Receptor-related Protein 1 via an Extended Surface Comprising "Hot-Spot" Lysine Residues. J Biol Chem 2015; 290:16463-76. [PMID: 25903134 DOI: 10.1074/jbc.m115.650911] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Indexed: 11/06/2022] Open
Abstract
Lysine residues are implicated in driving the ligand binding to the LDL receptor family. However, it has remained unclear how specificity is regulated. Using coagulation factor VIII as a model ligand, we now study the contribution of individual lysine residues in the interaction with the largest member of the LDL receptor family, low-density lipoprotein receptor-related protein (LRP1). Using hydrogen-deuterium exchange mass spectrometry (HDX-MS) and SPR interaction analysis on a library of lysine replacement variants as two independent approaches, we demonstrate that the interaction between factor VIII (FVIII) and LRP1 occurs over an extended surface containing multiple lysine residues. None of the individual lysine residues account completely for LRP1 binding, suggesting an additive binding model. Together with structural docking studies, our data suggest that FVIII interacts with LRP1 via an extended surface of multiple lysine residues that starts at the bottom of the C1 domain and winds around the FVIII molecule.
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Affiliation(s)
- Maartje van den Biggelaar
- From the Department of Plasma Proteins, Sanquin Blood Supply Foundation, 1066 CX Amsterdam, The Netherlands,
| | - Jesper J Madsen
- Global Research, Novo Nordisk A/S, DK-2760 Måløv, Denmark, and
| | - Johan H Faber
- Global Research, Novo Nordisk A/S, DK-2760 Måløv, Denmark, and
| | - Marleen G Zuurveld
- From the Department of Plasma Proteins, Sanquin Blood Supply Foundation, 1066 CX Amsterdam, The Netherlands
| | - Carmen van der Zwaan
- From the Department of Plasma Proteins, Sanquin Blood Supply Foundation, 1066 CX Amsterdam, The Netherlands
| | - Ole H Olsen
- Global Research, Novo Nordisk A/S, DK-2760 Måløv, Denmark, and
| | | | - Koen Mertens
- From the Department of Plasma Proteins, Sanquin Blood Supply Foundation, 1066 CX Amsterdam, The Netherlands, the Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3508 TC Utrecht, The Netherlands
| | - Alexander B Meijer
- From the Department of Plasma Proteins, Sanquin Blood Supply Foundation, 1066 CX Amsterdam, The Netherlands, the Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3508 TC Utrecht, The Netherlands
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32
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Madsen JJ, Persson E, Olsen OH. Tissue factor activates allosteric networks in factor VIIa through structural and dynamic changes. J Thromb Haemost 2015; 13:262-7. [PMID: 25403348 DOI: 10.1111/jth.12791] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 11/10/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Tissue factor (TF) promotes colocalization of enzyme (factor VIIa) and substrate (FX or FIX), and stabilizes the active conformation of FVIIa. Details on how TF induces structural and dynamic changes in the catalytic domain of FVIIa to enhance its efficiency remain elusive. OBJECTIVE To elucidate the activation of allosteric networks in the catalytic domain of the FVIIa protease it is when bound to TF. METHODS Long-timescale molecular dynamics simulations of FVIIa, free and in complex with TF, were executed and analyzed by dynamic network analysis. RESULTS Allosteric paths of correlated motion from the TF contact point, Met306, in FVIIa to the active site triad can be described and quantified. In particular, the shortest paths from Met306 to Ser344 and His193 are 16% and 8% longer in free FVIIa than in TF-FVIIa, and they encompass previously undiscovered residue-residue interactions that are not likely to be inferred from mutagenesis studies. Furthermore, paths from Met306 to Ile153 (N-terminus) and Trp364, both representing hallmark residues of allostery, are 7% and 37% longer, respectively, in free FVIIa. Thus, there is significantly weaker coupling between the TF contact point and key residues in the catalytic domain of FVIIa, causing the active site triad to disintegrate in the simulation when TF is not present. CONCLUSIONS These findings complement our current understanding of how the protease FVIIa is stimulated by TF. We demonstrate allosteric networks in the catalytic domain that are activated by TF and help to make FVIIa an efficient catalyst of FIX and FX activation.
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Affiliation(s)
- J J Madsen
- Haemophilia Biochemistry, Novo Nordisk A/S, Måløv, Denmark; DTU Chemistry, Technical University of Denmark, Kgs. Lyngby, Denmark
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Persson E, Madsen JJ, Olsen OH. The length of the linker between the epidermal growth factor-like domains in factor VIIa is critical for a productive interaction with tissue factor. Protein Sci 2014; 23:1717-27. [PMID: 25234571 DOI: 10.1002/pro.2553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/05/2022]
Abstract
Formation of the factor VIIa (FVIIa)-tissue factor (TF) complex triggers the blood coagulation cascade. Using a structure-based rationale, we investigated how the length of the linker region between the two epidermal growth factor (EGF)-like domains in FVIIa influences TF binding and the allosteric activity enhancement, as well as the interplay between the γ-carboxyglutamic acid (Gla)-containing and protease domains. Removal of two residues from the native linker was compatible with normal cofactor binding and accompanying stimulation of the enzymatic activity, as was extension by two (Gly-Ser) residues. In sharp contrast, truncation by three or four residues abolished the TF-mediated stabilization of the active conformation of FVIIa and abrogated TF-induced activity enhancement. In addition, FVIIa variants with short linkers associated 80-fold slower with soluble TF (sTF) as compared with wild-type FVIIa, resulting in a corresponding increase in the equilibrium dissociation constant. Molecular modeling suggested that the shortest FVIIa variants would have to be forced into a tense and energetically unfavorable conformation in order to be able to interact productively with TF, explaining our experimental observations. We also found a correlation between linker length and the residual intrinsic enzymatic activity of Ca(2+)-free FVIIa; stepwise truncation resulting in gradually higher activity with des(83-86)-FVIIa reaching the level of Gla-domainless FVIIa. The linker appears to determine the average distance between the negatively charged Gla domain and a structural element in the protease domain, presumably of opposite charge, and proximity has a negative impact on apo-FVIIa activity.
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Affiliation(s)
- Egon Persson
- Haemophilia Biology, Novo Nordisk A/S, Novo Nordisk Park, DK-2760, Måløv, Denmark
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Peters GH, Werge M, Elf-Lind MN, Madsen JJ, Velardez GF, Westh P. Interaction of neurotransmitters with a phospholipid bilayer: a molecular dynamics study. Chem Phys Lipids 2014; 184:7-17. [PMID: 25159594 DOI: 10.1016/j.chemphyslip.2014.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/14/2014] [Accepted: 08/22/2014] [Indexed: 11/15/2022]
Abstract
We have performed a series of molecular dynamics simulations to study the interactions between the neurotransmitters (NTs) γ-aminobutyrate (GABA), glycine (GLY), acetylcholine (ACH) and glutamate (GLU) as well as the amidated/acetylated γ-aminobutyrate (GABA(neu)) and the osmolyte molecule glycerol (GOL) with a dipalmitoylphosphatidylcholine (DPPC) bilayer. In agreement with previously published experimental data, we found the lowest membrane affinity for the charged molecules and a moderate affinity for zwitterionic and polar molecules. The affinity can be ranked as follows: ACH-GLU<<GABA<GLY<<GABA(neu)<<GOL. The latter three penetrated the bilayer at most with the deepest location being close to the glycerol backbone of the phospholipids. Even at that position, these solutes were noticeably hydrated and carried ∼30-80% of the bulk water along. The mobility of hydration water at the solute is also affected by the penetration into the bilayer. Two time scales of exchanging water molecules could be determined. In the bulk phase, the hydration layer contains ∼20% slow exchanging water molecules which increases 2-3 times as the solutes entered the bilayer. Our results indicate that there is no intermediate exchange of slow moving water molecules from the solutes to the lipid atoms and vice versa. Instead, the exchange relies on the reservoir of unbounded ("free") water molecules in the interfacial bilayer region. Results from the equilibrium simulations are in good agreement with the results from umbrella sampling simulations, which were conducted for the four naturally occurring NTs. Free energy profiles for ACH and GLU show a minimum of ∼2-3 kJ/mol close to the bilayer interface, while for GABA and GLY, a minimum of respectively ∼2 kJ/mol and ∼5 kJ/mol is observed when these NTs are located in the vicinity of the lipid glycerol backbone. The most important interaction of NTs with the bilayer is the charged amino group of NTs with the lipid phosphate group.
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Affiliation(s)
- Günther H Peters
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark.
| | - Mikkel Werge
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | | | - Jesper J Madsen
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Gustavo F Velardez
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Peter Westh
- NSM, Research Unit for Functional Biomaterials, Roskilde University, Roskilde 4000, Denmark.
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Abstract
Serotonin (5-hydroxytryptamine, 5-HT) is a prevalent neurotransmitter throughout the animal kingdom. It exerts its effect through the specific binding to the serotonin receptor, but recent research has suggested that neural transmission may also be affected by its nonspecific interactions with the lipid matrix of the synaptic membrane. However, membrane-5-HT interactions remain controversial and superficially investigated. Fundamental knowledge of this interaction appears vital in discussions of putative roles of 5-HT, and we have addressed this by thermodynamic measurements and molecular dynamics (MD) simulations. 5-HT was found to interact strongly with lipid bilayers (partitioning coefficient ~1200 in mole fraction units), and this is highly unusual for a hydrophilic solute like 5-HT which has a bulk, oil-water partitioning coefficient well below unity. It follows that membrane affinity must rely on specific interactions, and the MD simulations identified the salt-bridge between the primary amine of 5-HT and the lipid phosphate group as the most important interaction. This interaction anchored cationic 5-HT in the membrane interface with the aromatic ring system pointing inward and a prevailing residence between the phosphate and the carbonyl groups of the lipid. The unprotonated form of 5-HT shows the opposite orientation, with the primary amine pointing toward the membrane core. Partitioning of 5-HT was found to decrease lipid chain order. These distinctive interactions of 5-HT and model membranes could be related to nonspecific effects of this neurotransmitter.
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Affiliation(s)
- Günther H Peters
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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Abstract
We have studied secretory phospholipase A(2)-IIA (sPLA(2)) activity toward different phospholipid analogues by performing biophysical characterizations and molecular dynamics simulations. The phospholipids were natural substrates, triple alkyl phospholipids, a prodrug anticancer etherlipid, and an inverted ester. The latter were included to study head group-enzyme interactions. Our simulation results show that the lipids are optimally placed into the binding cleft and that water molecules can freely reach the active site through a well-defined pathway; both are indicative that these substrates are efficiently hydrolyzed, which is in good agreement with our experimental data. The phospholipid analogue with three alkyl side chains forms aggregates of different shapes with no well-defined sizes due to its cone-shape structure. Phosphatidylglycerol and phosphatidylcholine head groups interact with specific charged residues, but relatively large fluctuations are observed, suggesting that these interactions are not necessarily important for stabilizing substrate binding to the enzyme.
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Affiliation(s)
- Jesper J Madsen
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby, Denmark
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Skov MN, Madsen JJ, Rahbek C, Lodal J, Jespersen JB, Jørgensen JC, Dietz HH, Chriél M, Baggesen DL. Transmission of Salmonella between wildlife and meat-production animals in Denmark. J Appl Microbiol 2010; 105:1558-68. [PMID: 19146492 DOI: 10.1111/j.1365-2672.2008.03914.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To investigate the transmission of Salmonella spp. between production animals (pigs and cattle) and wildlife on production animal farms in Denmark. METHODS AND RESULTS In the winter and summer of 2001 and 2002, 3622 samples were collected from Salmonella-infected and noninfected herds of pigs and cattle and surrounding wildlife. Salmonella was detected in wildlife on farms carrying Salmonella-positive production animals and only during the periods when Salmonella was detected in the production animals. The presence of Salmonella Typhimurium in wild birds significantly correlated to their migration pattern and food preference. CONCLUSIONS Salmonella was transmitted from infected herds of production animals (cattle and pigs) to wildlife that lived amongst or in close proximity to them. SIGNIFICANCE AND IMPACT OF THE STUDY Salmonella in animal food products is associated with the occurrence of Salmonella in primary animal production. Strategies to control the introduction and spread of infection should include wildlife management, as the nearby wildlife may act as reservoirs for Salmonella spp. and/or may be passive carriers of the bacteria.
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Affiliation(s)
- M N Skov
- National Food Institute, The Technical University of Denmark, Copenhagen V, Denmark
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Nielsen EM, Skov MN, Madsen JJ, Lodal J, Jespersen JB, Baggesen DL. Verocytotoxin-producing Escherichia coli in wild birds and rodents in close proximity to farms. Appl Environ Microbiol 2005; 70:6944-7. [PMID: 15528570 PMCID: PMC525191 DOI: 10.1128/aem.70.11.6944-6947.2004] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission.
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Madsen JJ. Comparison of concurrent and retrospective methods of detecting adverse drug reactions. Am J Hosp Pharm 1993; 50:2556-7. [PMID: 8122693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- J J Madsen
- Fairview Riverside Medical Center, Minneapolis, MN 55454
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