1
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de Armiño DJA, Di Lella S, Montepietra D, Delcanale P, Bruno S, Giordano D, Verde C, Estrin DA, Viappiani C, Abbruzzetti S. Kinetic and dynamical properties of truncated hemoglobins of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125. Protein Sci 2024; 33:e5064. [PMID: 38864722 PMCID: PMC11168075 DOI: 10.1002/pro.5064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/07/2024] [Accepted: 05/14/2024] [Indexed: 06/13/2024]
Abstract
Due to the low temperature, the Antarctic marine environment is challenging for protein functioning. Cold-adapted organisms have evolved proteins endowed with higher flexibility and lower stability in comparison to their thermophilic homologs, resulting in enhanced reaction rates at low temperatures. The Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125) genome is one of the few examples of coexistence of multiple hemoglobin genes encoding, among others, two constitutively transcribed 2/2 hemoglobins (2/2Hbs), also named truncated Hbs (TrHbs), belonging to the Group II (or O), annotated as PSHAa0030 and PSHAa2217. In this work, we describe the ligand binding kinetics and their interrelationship with the dynamical properties of globin Ph-2/2HbO-2217 by combining experimental and computational approaches and implementing a new computational method to retrieve information from molecular dynamic trajectories. We show that our approach allows us to identify docking sites within the protein matrix that are potentially able to transiently accommodate ligands and migration pathways connecting them. Consistently with ligand rebinding studies, our modeling suggests that the distal heme pocket is connected to the solvent through a low energy barrier, while inner cavities play only a minor role in modulating rebinding kinetics.
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Affiliation(s)
- Diego Javier Alonso de Armiño
- Departamento de Química Inorgánica, Analítica y Química Física, and INQUIMAE‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Santiago Di Lella
- Departamento de Química Biológica and IQUIBICEN‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Daniele Montepietra
- Department of Chemistry, Life Sciences and Environmental SustainabilityUniversity of ParmaParmaItaly
- Nanoscience Institute—CNR‐NANOModenaItaly
| | - Pietro Delcanale
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
| | - Stefano Bruno
- Department of Food and Drug SciencesUniversity of ParmaParmaItaly
| | - Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), CNRNaplesItaly
- Department of Ecosustainable Marine BiotechnologyStazione Zoologica Anton DohrnNaplesItaly
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), CNRNaplesItaly
- Department of Ecosustainable Marine BiotechnologyStazione Zoologica Anton DohrnNaplesItaly
| | - Dario A. Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, and INQUIMAE‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Cristiano Viappiani
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
| | - Stefania Abbruzzetti
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
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2
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Lopez ED, Burastero O, Arcon JP, Defelipe LA, Ahn NG, Marti MA, Turjanski AG. Kinase Activation by Small Conformational Changes. J Chem Inf Model 2019; 60:821-832. [PMID: 31714778 DOI: 10.1021/acs.jcim.9b00782] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein kinases (PKs) are allosteric enzymes that play an essential role in signal transduction by regulating a variety of key cellular processes. Most PKs suffer conformational rearrangements upon phosphorylation that strongly enhance the catalytic activity. Generally, it involves the movement of the phosphorylated loop toward the active site and the rotation of the whole C-terminal lobe. However, not all kinases undergo such a large configurational change: The MAPK extracellular signal-regulated protein kinases ERK1 and ERK2 achieve a 50 000 fold increase in kinase activity with only a small motion of the C-terminal region. In the present work, we used a combination of molecular simulation tools to characterize the conformational landscape of ERK2 in the active (phosphorylated) and inactive (unphosphorylated) states in solution in agreement with NMR experiments. We show that the chemical reaction barrier is strongly dependent on ATP conformation and that the "active" low-barrier configuration is subtly regulated by phosphorylation, which stabilizes a key salt bridge between the conserved Lys52 and Glu69 belonging to helix-C and promotes binding of a second Mg ion. Our study highlights that the on-off switch embedded in the kinase fold can be regulated by small, medium, and large conformational changes.
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Affiliation(s)
- Elias D Lopez
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
| | - Osvaldo Burastero
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
| | - Juan P Arcon
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
| | - Lucas A Defelipe
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
| | - Natalie G Ahn
- Department of Chemistry and Biochemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Marcelo A Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
| | - Adrian G Turjanski
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Autónoma de Buenos Aires , Argentina
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3
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Bringas M, Lombardi LE, Luque FJ, Estrin DA, Capece L. Ligand Binding Rate Constants in Heme Proteins Using Markov State Models and Molecular Dynamics Simulations. Chemphyschem 2019; 20:2451-2460. [PMID: 31365183 DOI: 10.1002/cphc.201900589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/30/2019] [Indexed: 11/07/2022]
Abstract
Computer simulation studies of the molecular basis for ligand migration in proteins allow the description of key events such as the transition between docking sites, displacement of existing ligands and solvent molecules, and open/closure of specific "gates", among others. In heme proteins, ligand migration from the solvent to the active site preludes the binding to the heme iron and triggers different functions. In this work, molecular dynamics simulations, a Markov State Model of migration and empirical kinetic equations are combined to study the migration of O2 and NO in two truncated hemoglobins of Mycobacterium tuberculosis (Mt-TrHbN and Mt-TrHbO). For Mt-TrHbN, we show that the difference in the association constant in the oxy and deoxy states relies mainly in the displacement of water molecules anchored in the distal cavity in the deoxy form. The results here provide a valuable approach to study ligand migration in globins.
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Affiliation(s)
- Mauro Bringas
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.,Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-CONICET), C1428EGA, Buenos Aires, Argentina
| | - Leandro E Lombardi
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires - CONICET, C1428EGA, Buenos Aires, Argentina
| | - F Javier Luque
- Department of Nutrition, Food Sciences and Gastronomy, Faculty of Pharmacy and Food Sciences, University of Barcelona, Campus Torribera, 08921, Santa Coloma de Gramenet, Spain.,Institute of Biomedicine (IBUB) and Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, 08028, Barcelona, Spain
| | - Darío A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.,Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-CONICET), C1428EGA, Buenos Aires, Argentina
| | - Luciana Capece
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.,Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-CONICET), C1428EGA, Buenos Aires, Argentina
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4
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Arrar M, Boubeta FM, Szretter ME, Sued M, Boechi L, Rodriguez D. On the accurate estimation of free energies using the jarzynski equality. J Comput Chem 2018; 40:688-696. [DOI: 10.1002/jcc.25754] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/18/2018] [Accepted: 09/03/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Mehrnoosh Arrar
- Instituto de Química-Física de los Materiales, Medio Ambiente y Energía, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina, Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
| | - Fernando Martín Boubeta
- Instituto de Química-Física de los Materiales, Medio Ambiente y Energía, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina, Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
| | - Maria Eugenia Szretter
- Departamento de Matemática, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina, Instituto de Cálculo, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
| | - Mariela Sued
- Instituto de Cálculo, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
| | - Leonardo Boechi
- Instituto de Cálculo, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
| | - Daniela Rodriguez
- Instituto de Cálculo, CONICET-Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires; Buenos Aires Argentina
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5
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Boubeta FM, Boechi L, Estrin D, Patrizi B, Di Donato M, Iagatti A, Giordano D, Verde C, Bruno S, Abbruzzetti S, Viappiani C. Cold-Adaptation Signatures in the Ligand Rebinding Kinetics to the Truncated Hemoglobin of the Antarctic Bacterium Pseudoalteromonas haloplanktis TAC125. J Phys Chem B 2018; 122:11649-11661. [PMID: 30230844 DOI: 10.1021/acs.jpcb.8b07682] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cold-adapted organisms have evolved proteins endowed with higher flexibility and lower stability in comparison to their thermophilic homologues, resulting in enhanced reaction rates at low temperatures. In this context, protein-bound water molecules were suggested to play a major role, and their weaker interactions at protein active sites have been associated with cold adaptation. In this work, we tested this hypothesis on truncated hemoglobins (a family of microbial heme-proteins of yet-unclear function) applying molecular dynamics simulations and ligand-rebinding kinetics on a protein from the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 in comparison with its thermophilic Thermobifida fusca homologue. The CO rebinding kinetics of the former highlight several geminate phases, with an unusually long-lived geminate intermediate. An articulated tunnel with at least two distinct docking sites was identified by analysis of molecular dynamics simulations and was suggested to be at the origin of the unusual geminate rebinding phase. Water molecules are present in the distal pocket, but their stabilization by TrpG8, TyrB10, and HisCD1 is much weaker than in thermophilic Thermobifida fusca truncated hemoglobin, resulting in a faster geminate rebinding. Our results support the hypothesis that weaker water-molecule interactions at the reaction site are associated with cold adaptation.
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Affiliation(s)
- Fernando M Boubeta
- Instituto de Quimica Fisica de los Materiales, Medio Ambiente y Energia (INQUIMAE), CONICET, and Universidad de Buenos Aires , C1428EHA Buenos Aires , Argentina
| | - Leonardo Boechi
- Instituto de Calculo, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , C1428EGA Buenos Aires , Argentina
| | - Dario Estrin
- Instituto de Quimica Fisica de los Materiales, Medio Ambiente y Energia (INQUIMAE), CONICET, and Universidad de Buenos Aires , C1428EHA Buenos Aires , Argentina
| | - Barbara Patrizi
- European Laboratory for Non Linear Spectroscopy (LENS), Università di Firenze , Via Nello Carrara 1 , 50019 Sesto Fiorentino, Florence , Italy.,INO-CNR, Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche , Largo Fermi 6 , 50125 Florence , Italy
| | - Mariangela Di Donato
- European Laboratory for Non Linear Spectroscopy (LENS), Università di Firenze , Via Nello Carrara 1 , 50019 Sesto Fiorentino, Florence , Italy.,INO-CNR, Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche , Largo Fermi 6 , 50125 Florence , Italy
| | - Alessandro Iagatti
- European Laboratory for Non Linear Spectroscopy (LENS), Università di Firenze , Via Nello Carrara 1 , 50019 Sesto Fiorentino, Florence , Italy
| | - Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), CNR , Via Pietro Castellino 111 , I-80131 Naples , Italy.,Stazione Zoologica Anton Dohrn , Villa Comunale , 80121 Naples , Italy
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), CNR , Via Pietro Castellino 111 , I-80131 Naples , Italy.,Stazione Zoologica Anton Dohrn , Villa Comunale , 80121 Naples , Italy
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco , Università di Parma , Parco Area delle Scienze 23A , 43124 , Parma , Italy
| | - Stefania Abbruzzetti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche , Università di Parma , Parco Area delle Scienze 7A , 43124 , Parma , Italy
| | - Cristiano Viappiani
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche , Università di Parma , Parco Area delle Scienze 7A , 43124 , Parma , Italy
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6
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Do PC, Lee EH, Le L. Steered Molecular Dynamics Simulation in Rational Drug Design. J Chem Inf Model 2018; 58:1473-1482. [DOI: 10.1021/acs.jcim.8b00261] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Phuc-Chau Do
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
| | - Eric H. Lee
- Department of Medicine and Division of Hematology and Oncology, Loma Linda University Medical Center, Loma Linda, California 92350, United States
| | - Ly Le
- School of Biotechnology, International University, Vietnam National University, Ho Chi Minh City 700000, Vietnam
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7
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Abdizadeh H, Atilgan AR, Atilgan C, Dedeoglu B. Computational approaches for deciphering the equilibrium and kinetic properties of iron transport proteins. Metallomics 2018; 9:1513-1533. [PMID: 28967944 DOI: 10.1039/c7mt00216e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
With the advances in three-dimensional structure determination techniques, high quality structures of the iron transport proteins transferrin and the bacterial ferric binding protein (FbpA) have been deposited in the past decade. These are proteins of relatively large size, and developments in hardware and software have only recently made it possible to study their dynamics using standard computational resources. We review computational techniques towards understanding the equilibrium and kinetic properties of iron transport proteins under different environmental conditions. At the level of detail that requires quantum chemical treatments, the octahedral geometry around iron has been scrutinized and it has been established that the iron coordinating tyrosines are in an unusual deprotonated state. At the atomistic level, both the N-lobe and the full bilobal structure of transferrin have been studied under varying conditions of pH, ionic strength and binding of other metal ions by molecular dynamics (MD) simulations. These studies have allowed questions to be answered, among others, on the function of second shell residues in iron release, the role of synergistic anions in preparing the active site for iron binding, and the differences between the kinetics of the N- and the C-lobe. MD simulations on FbpA have led to the detailed observation of the binding kinetics of phosphate to the apo form, and to the conformational preferences of the holo form under conditions mimicking the environmental niches provided by the periplasmic space. To study the dynamics of these proteins with their receptors, one must resort to coarse-grained methodologies, since these systems are prohibitively large for atomistic simulations. A study of the complex of human transferrin (hTf) with its pathogenic receptor by such methods has revealed a potential mechanistic explanation for the defense mechanism that arises in evolutionary warfare. Meanwhile, the motions in the transferrin receptor bound hTf have been shown to disfavor apo hTf dissociation, explaining why the two proteins remain in complex during the recycling process from the endosome to the cell surface. Open problems and possible technological applications related to metal ion binding-release in iron transport proteins that may be handled by hybrid use of quantum mechanical, MD and coarse-grained approaches are discussed.
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Affiliation(s)
- H Abdizadeh
- Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı 34956, Tuzla, Istanbul, Turkey.
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8
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Boubeta FM, Bieza SA, Bringas M, Estrin DA, Boechi L, Bari SE. Mechanism of Sulfide Binding by Ferric Hemeproteins. Inorg Chem 2018; 57:7591-7600. [DOI: 10.1021/acs.inorgchem.8b00478] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fernando M. Boubeta
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), CONICET and Universidad de Buenos Aires, Buenos Aires 1053, Argentina
| | - Silvina A. Bieza
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), CONICET and Universidad de Buenos Aires, Buenos Aires 1053, Argentina
| | - Mauro Bringas
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), CONICET and Universidad de Buenos Aires, Buenos Aires 1053, Argentina
| | - Darío A. Estrin
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), CONICET and Universidad de Buenos Aires, Buenos Aires 1053, Argentina
| | | | - Sara E. Bari
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), CONICET and Universidad de Buenos Aires, Buenos Aires 1053, Argentina
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9
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Tertiary and quaternary structural basis of oxygen affinity in human hemoglobin as revealed by multiscale simulations. Sci Rep 2017; 7:10926. [PMID: 28883619 PMCID: PMC5589765 DOI: 10.1038/s41598-017-11259-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 08/22/2017] [Indexed: 11/30/2022] Open
Abstract
Human hemoglobin (Hb) is a benchmark protein of structural biology that shaped our view of allosterism over 60 years ago, with the introduction of the MWC model based on Perutz structures of the oxy(R) and deoxy(T) states and the more recent Tertiary Two-State model that proposed the existence of individual subunit states -“r” and “t”-, whose structure is yet unknown. Cooperative oxygen binding is essential for Hb function, and despite decades of research there are still open questions related to how tertiary and quaternary changes regulate oxygen affinity. In the present work, we have determined the free energy profiles of oxygen migration and for HisE7 gate opening, with QM/MM calculations of the oxygen binding energy in order to address the influence of tertiary differences in the control of oxygen affinity. Our results show that in the α subunit the low to high affinity transition is achieved by a proximal effect that mostly affects oxygen dissociation and is the driving force of the allosteric transition, while in the β subunit the affinity change results from a complex interplay of proximal and distal effects, including an increase in the HE7 gate opening, that as shown by free energy profiles promotes oxygen uptake.
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10
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Nategholeslam M, Gray CG, Tomberli B. Stiff Spring Approximation Revisited: Inertial Effects in Nonequilibrium Trajectories. J Phys Chem B 2017; 121:391-403. [DOI: 10.1021/acs.jpcb.6b08701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - C. G. Gray
- Guelph-Waterloo
Physics Institute and Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Bruno Tomberli
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
- Department
of Physics, Capilano University, North Vancouver, British
Columbia V7J 3H5, Canada
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11
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Issoglio FM, Campolo N, Zeida A, Grune T, Radi R, Estrin DA, Bartesaghi S. Exploring the Catalytic Mechanism of Human Glutamine Synthetase by Computer Simulations. Biochemistry 2016; 55:5907-5916. [DOI: 10.1021/acs.biochem.6b00822] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Federico M. Issoglio
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Ari Zeida
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Tilman Grune
- German Institute of Human Nutrition (DIfE) Potsdam-Rehbrücke, Department of Molecular Toxicology, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | | | - Dario A. Estrin
- Departamento
de Química Inorgánica, Analítica y Química-Física
and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Silvina Bartesaghi
- Departamento
de Educación Médica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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12
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Boubeta FM, Bari SE, Estrin DA, Boechi L. Access and Binding of H2S to Hemeproteins: The Case of HbI of Lucina pectinata. J Phys Chem B 2016; 120:9642-53. [DOI: 10.1021/acs.jpcb.6b06686] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Fernando M. Boubeta
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales,
Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires C1428EHA, Argentina
| | - Sara E. Bari
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales,
Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires C1428EHA, Argentina
| | - Dario A. Estrin
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales,
Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, Buenos Aires C1428EHA, Argentina
| | - Leonardo Boechi
- Instituto de Cálculo/CONICET,
Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires,
Ciudad Universitaria, Pab. II, Buenos Aires C1428EHA, Argentina
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13
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Zhang Z, Santos AP, Zhou Q, Liang L, Wang Q, Wu T, Franzen S. Steered molecular dynamics study of inhibitor binding in the internal binding site in dehaloperoxidase-hemoglobin. Biophys Chem 2016; 211:28-38. [DOI: 10.1016/j.bpc.2016.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/24/2015] [Accepted: 01/12/2016] [Indexed: 10/22/2022]
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14
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Giovannelli E, Cardini G, Chelli R. Elastic Barrier Dynamical Freezing in Free Energy Calculations: A Way To Speed Up Nonequilibrium Molecular Dynamics Simulations by Orders of Magnitude. J Chem Theory Comput 2016; 12:1029-39. [PMID: 26771534 DOI: 10.1021/acs.jctc.5b01117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
An important issue concerning computer simulations addressed to free energy estimates via nonequilibrium work theorems, such as the Jarzynski equality [Phys. Rev. Lett. 1997, 78, 2690], is the computational effort required to achieve results with acceptable accuracy. In this respect, the dynamical freezing approach [Phys. Rev. E 2009, 80, 041124] has been shown to improve the efficiency of this kind of simulations, by blocking the dynamics of particles located outside an established mobility region. In this report, we show that dynamical freezing produces a systematic spurious decrease of the particle density inside the mobility region. As a consequence, the requirements to apply nonequilibrium work theorems are only approximately met. Starting from these considerations, we have developed a simulation scheme, called "elastic barrier dynamical freezing", according to which a stiff potential-energy barrier is enforced at the boundaries of the mobility region, preventing the particles from leaving this region of space during the nonequilibrium trajectories. The method, tested on the calculation of the distance-dependent free energy of a dimer immersed into a Lennard-Jones fluid, provides an accuracy comparable to the conventional steered molecular dynamics, with a computational speedup exceeding a few orders of magnitude.
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Affiliation(s)
- Edoardo Giovannelli
- Dipartimento di Chimica, Università di Firenze , Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
| | - Gianni Cardini
- Dipartimento di Chimica, Università di Firenze , Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
| | - Riccardo Chelli
- Dipartimento di Chimica, Università di Firenze , Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
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15
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Bustamante JP, Radusky L, Boechi L, Estrin DA, ten Have A, Martí MA. Evolutionary and Functional Relationships in the Truncated Hemoglobin Family. PLoS Comput Biol 2016; 12:e1004701. [PMID: 26788940 PMCID: PMC4720485 DOI: 10.1371/journal.pcbi.1004701] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 12/10/2015] [Indexed: 12/21/2022] Open
Abstract
Predicting function from sequence is an important goal in current biological research, and although, broad functional assignment is possible when a protein is assigned to a family, predicting functional specificity with accuracy is not straightforward. If function is provided by key structural properties and the relevant properties can be computed using the sequence as the starting point, it should in principle be possible to predict function in detail. The truncated hemoglobin family presents an interesting benchmark study due to their ubiquity, sequence diversity in the context of a conserved fold and the number of characterized members. Their functions are tightly related to O2 affinity and reactivity, as determined by the association and dissociation rate constants, both of which can be predicted and analyzed using in-silico based tools. In the present work we have applied a strategy, which combines homology modeling with molecular based energy calculations, to predict and analyze function of all known truncated hemoglobins in an evolutionary context. Our results show that truncated hemoglobins present conserved family features, but that its structure is flexible enough to allow the switch from high to low affinity in a few evolutionary steps. Most proteins display moderate to high oxygen affinities and multiple ligand migration paths, which, besides some minor trends, show heterogeneous distributions throughout the phylogenetic tree, again suggesting fast functional adaptation. Our data not only deepens our comprehension of the structural basis governing ligand affinity, but they also highlight some interesting functional evolutionary trends.
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Affiliation(s)
- Juan P. Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Leandro Radusky
- Departamento de Química Biológica e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Leonardo Boechi
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Darío A. Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Arjen ten Have
- Instituto de Investigación Biológica, CONICET, Universidad Nacional de Mar del Plata. Buenos Aires, Argentina
| | - Marcelo A. Martí
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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16
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Pesce A, Bustamante JP, Bidon-Chanal A, Boechi L, Estrin DA, Luque FJ, Sebilo A, Guertin M, Bolognesi M, Ascenzi P, Nardini M. The N-terminal pre-A region of Mycobacterium tuberculosis 2/2HbN promotes NO-dioxygenase activity. FEBS J 2015; 283:305-22. [PMID: 26499089 DOI: 10.1111/febs.13571] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 08/09/2015] [Accepted: 08/16/2015] [Indexed: 01/24/2023]
Abstract
UNLABELLED A unique defense mechanisms by which Mycobacterium tuberculosis protects itself from nitrosative stress is based on the O2 -dependent NO-dioxygenase (NOD) activity of truncated hemoglobin 2/2HbN (Mt2/2HbN). The NOD activity largely depends on the efficiency of ligand migration to the heme cavity through a two-tunnel (long and short) system; recently, it was also correlated with the presence at the Mt2/2HbN N-terminus of a short pre-A region, not conserved in most 2/2HbNs, whose deletion results in a drastic reduction of NO scavenging. In the present study, we report the crystal structure of Mt2/2HbN-ΔpreA, lacking the pre-A region, at a resolution of 1.53 Å. We show that removal of the pre-A region results in long range effects on the protein C-terminus, promoting the assembly of a stable dimer, both in the crystals and in solution. In the Mt2/2HbN-ΔpreA dimer, access of heme ligands to the short tunnel is hindered. Molecular dynamics simulations show that the long tunnel branch is the only accessible pathway for O2 -ligand migration to/from the heme, and that the gating residue Phe(62)E15 partly restricts the diameter of the tunnel. Accordingly, kinetic measurements indicate that the kon value for peroxynitrite isomerization by Mt2/2HbN-ΔpreA-Fe(III) is four-fold lower relative to the full-length protein, and that NO scavenging by Mt2/2HbN-ΔpreA-Fe(II)-O2 is reduced by 35-fold. Therefore, we speculate that Mt2/2HbN evolved to host the pre-A region as a mechanism for preventing dimerization, thus reinforcing the survival of the microorganism against the reactive nitrosative stress in macrophages. DATABASE Coordinates and structure factors have been deposited in the Protein Data Bank under accession number 5AB8.
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Affiliation(s)
| | - Juan P Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Argentina
| | - Axel Bidon-Chanal
- Departament de Fisicoquímica and Institut de Biomedicina (IBUB), Facultat de Farmàcia, University of Barcelona, Santa Coloma de Gramenet, Spain
| | - Leonardo Boechi
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Argentina
| | - Darío A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Argentina
| | - Francisco Javier Luque
- Departament de Fisicoquímica and Institut de Biomedicina (IBUB), Facultat de Farmàcia, University of Barcelona, Santa Coloma de Gramenet, Spain
| | - Anne Sebilo
- Department of Biochemistry, Microbiology and Bioinformatics, Laval University, Quebec, Canada
| | - Michel Guertin
- Department of Biochemistry, Microbiology and Bioinformatics, Laval University, Quebec, Canada
| | - Martino Bolognesi
- Department of Biosciences, University of Milan, Italy.,CNR-IBF and CIMAINA, University of Milan, Italy
| | - Paolo Ascenzi
- Interdepartmental Laboratory of Electron Microscopy, Roma Tre University, Rome, Italy.,National Institute of Biostructures and Biosystems, Rome, Italy
| | - Marco Nardini
- Department of Biosciences, University of Milan, Italy
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17
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Di Russo NV, Condurso HL, Li K, Bruner SD, Roitberg AE. Oxygen diffusion pathways in a cofactor-independent dioxygenase. Chem Sci 2015; 6:6341-6348. [PMID: 26508997 PMCID: PMC4618494 DOI: 10.1039/c5sc01638j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A combination of experimental and computational studies reveals the main O2 diffusion pathways, providing insight into how cofactor-independent oxygenases control stereospecificity and prevent oxidative inactivation.
Molecular oxygen plays an important role in a wide variety of enzymatic reactions. Through recent research efforts combining computational and experimental methods a new view of O2 diffusion is emerging, where specific channels guide O2 to the active site. The focus of this work is DpgC, a cofactor-independent oxygenase. Molecular dynamics simulations, together with mutagenesis experiments and xenon-binding data, reveal that O2 reaches the active site of this enzyme using three main pathways and four different access points. These pathways connect a series of dynamic hydrophobic pockets, concentrating O2 at a specific face of the enzyme substrate. Extensive molecular dynamics simulations provide information about which pathways are more frequently used. This data is consistent with the results of kinetic measurements on mutants and is difficult to obtain using computational cavity-location methods. Taken together, our results reveal that although DpgC is rare in its ability of activating O2 in the absence of cofactors or metals, the way O2 reaches the active site is similar to that reported for other O2-using proteins: multiple access channels are available, and the architecture of the pathway network can provide regio- and stereoselectivity. Our results point to the existence of common themes in O2 access that are conserved among very different types of proteins.
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Affiliation(s)
- Natali V Di Russo
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
| | - Heather L Condurso
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
| | - Kunhua Li
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
| | - Steven D Bruner
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
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18
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Giordano D, Pesce A, Boechi L, Bustamante JP, Caldelli E, Howes BD, Riccio A, di Prisco G, Nardini M, Estrin D, Smulevich G, Bolognesi M, Verde C. Structural flexibility of the heme cavity in the cold-adapted truncated hemoglobin from the Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125. FEBS J 2015; 282:2948-65. [PMID: 26040838 DOI: 10.1111/febs.13335] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/17/2015] [Accepted: 06/01/2015] [Indexed: 11/30/2022]
Abstract
Truncated hemoglobins build one of the three branches of the globin protein superfamily. They display a characteristic two-on-two α-helical sandwich fold and are clustered into three groups (I, II and III) based on distinct structural features. Truncated hemoglobins are present in eubacteria, cyanobacteria, protozoa and plants. Here we present a structural, spectroscopic and molecular dynamics characterization of a group-II truncated hemoglobin, encoded by the PSHAa0030 gene from Pseudoalteromonas haloplanktis TAC125 (Ph-2/2HbO), a cold-adapted Antarctic marine bacterium hosting one flavohemoglobin and three distinct truncated hemoglobins. The Ph-2/2HbO aquo-met crystal structure (at 2.21 Å resolution) shows typical features of group-II truncated hemoglobins, namely the two-on-two α-helical sandwich fold, a helix Φ preceding the proximal helix F, and a heme distal-site hydrogen-bonded network that includes water molecules and several distal-site residues, including His(58)CD1. Analysis of Ph-2/2HbO by electron paramagnetic resonance, resonance Raman and electronic absorption spectra, under varied solution conditions, shows that Ph-2/2HbO can access diverse heme ligation states. Among these, detection of a low-spin heme hexa-coordinated species suggests that residue Tyr(42)B10 can undergo large conformational changes in order to act as the sixth heme-Fe ligand. Altogether, the results show that Ph-2/2HbO maintains the general structural features of group-II truncated hemoglobins but displays enhanced conformational flexibility in the proximity of the heme cavity, a property probably related to the functional challenges, such as low temperature, high O2 concentration and low kinetic energy of molecules, experienced by organisms living in the Antarctic environment.
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Affiliation(s)
- Daniela Giordano
- Institute of Biosciences and BioResources, National Research Council, Napoli, Italy
| | | | - Leonardo Boechi
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Argentina
| | - Juan Pablo Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Argentina
| | - Elena Caldelli
- Department of Chemistry 'Ugo Schiff', University of Firenze, Sesto Fiorentino, Italy
| | - Barry D Howes
- Department of Chemistry 'Ugo Schiff', University of Firenze, Sesto Fiorentino, Italy
| | - Alessia Riccio
- Institute of Biosciences and BioResources, National Research Council, Napoli, Italy
| | - Guido di Prisco
- Institute of Biosciences and BioResources, National Research Council, Napoli, Italy
| | - Marco Nardini
- Department of Biosciences, University of Milano, Italy
| | - Dario Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Argentina
| | - Giulietta Smulevich
- Department of Chemistry 'Ugo Schiff', University of Firenze, Sesto Fiorentino, Italy
| | - Martino Bolognesi
- Department of Biosciences, University of Milano, Italy.,CNR-Institute of Biophysics and CIMAINA, University of Milano, Italy
| | - Cinzia Verde
- Institute of Biosciences and BioResources, National Research Council, Napoli, Italy.,Department of Biology, Roma 3 University, Italy
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19
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Defelipe LA, Lanzarotti E, Gauto D, Marti MA, Turjanski AG. Protein topology determines cysteine oxidation fate: the case of sulfenyl amide formation among protein families. PLoS Comput Biol 2015; 11:e1004051. [PMID: 25741692 PMCID: PMC4351059 DOI: 10.1371/journal.pcbi.1004051] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 11/17/2014] [Indexed: 02/07/2023] Open
Abstract
Cysteine residues have a rich chemistry and play a critical role in the catalytic activity of a plethora of enzymes. However, cysteines are susceptible to oxidation by Reactive Oxygen and Nitrogen Species, leading to a loss of their catalytic function. Therefore, cysteine oxidation is emerging as a relevant physiological regulatory mechanism. Formation of a cyclic sulfenyl amide residue at the active site of redox-regulated proteins has been proposed as a protection mechanism against irreversible oxidation as the sulfenyl amide intermediate has been identified in several proteins. However, how and why only some specific cysteine residues in particular proteins react to form this intermediate is still unknown. In the present work using in-silico based tools, we have identified a constrained conformation that accelerates sulfenyl amide formation. By means of combined MD and QM/MM calculation we show that this conformation positions the NH backbone towards the sulfenic acid and promotes the reaction to yield the sulfenyl amide intermediate, in one step with the concomitant release of a water molecule. Moreover, in a large subset of the proteins we found a conserved beta sheet-loop-helix motif, which is present across different protein folds, that is key for sulfenyl amide production as it promotes the previous formation of sulfenic acid. For catalytic activity, in several cases, proteins need the Cysteine to be in the cysteinate form, i.e. a low pKa Cys. We found that the conserved motif stabilizes the cysteinate by hydrogen bonding to several NH backbone moieties. As cysteinate is also more reactive toward ROS we propose that the sheet-loop-helix motif and the constraint conformation have been selected by evolution for proteins that need a reactive Cys protected from irreversible oxidation. Our results also highlight how fold conservation can be correlated to redox chemistry regulation of protein function. Cysteine oxidation is emerging as a relevant regulatory mechanism of enzymatic function in the cell. Many proteins are protected from over oxidation by reactive oxygen species by the formation of a cyclic sulfenyl amide. Understanding how cyclic sulfenyl amide is formed and its dependence on protein structure is not only a basic question but necessary to predict which proteins may auto protect from over oxidation We describe a structural motif, which includes cysteine residues with a constrained conformation in a “forbidden” region of the Ramachandran plot plus a Beta-Cys-loop-helix motif, which has a reactive low pKa Cysteine and also enables to form the cyclic sulfenyl amide with a low activation barrier. Our QM/MM computations show that the cyclization reaction only occurs if the “forbidden” conformation is acquired by the Cysteine residue. This structural motif was identified at least in 7 PFAM families and 145 proteins with solved structure, showing that a large number of proteins could have the ability to go through such cyclic product preventing irreversible oxidation.
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Affiliation(s)
- Lucas A. Defelipe
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- INQUIMAE/UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Esteban Lanzarotti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Diego Gauto
- INQUIMAE/UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina
| | - Marcelo A. Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- INQUIMAE/UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina
- * E-mail: (MAM); (AGT)
| | - Adrián G. Turjanski
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- INQUIMAE/UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Buenos Aires, Argentina
- * E-mail: (MAM); (AGT)
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20
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Boron I, Bustamante JP, Davidge KS, Singh S, Bowman LAH, Tinajero-Trejo M, Carballal S, Radi R, Poole RK, Dikshit K, Estrin DA, Marti MA, Boechi L. Ligand uptake in Mycobacterium tuberculosis truncated hemoglobins is controlled by both internal tunnels and active site water molecules. F1000Res 2015; 4:22. [PMID: 26478812 PMCID: PMC4591903 DOI: 10.12688/f1000research.5921.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/20/2015] [Indexed: 11/23/2022] Open
Abstract
Mycobacterium tuberculosis, the causative agent of human tuberculosis, has two proteins belonging to the truncated hemoglobin (trHb) family. Mt-trHbN presents well-defined internal hydrophobic tunnels that allow O 2 and •NO to migrate easily from the solvent to the active site, whereas Mt-trHbO possesses tunnels interrupted by a few bulky residues, particularly a tryptophan at position G8. Differential ligand migration rates allow Mt-trHbN to detoxify •NO, a crucial step for pathogen survival once under attack by the immune system, much more efficiently than Mt-trHbO. In order to investigate the differences between these proteins, we performed experimental kinetic measurements, •NO decomposition, as well as molecular dynamics simulations of the wild type Mt-trHbN and two mutants, VG8F and VG8W. These mutations affect both the tunnels accessibility as well as the affinity of distal site water molecules, thus modifying the ligand access to the iron. We found that a single mutation allows Mt-trHbN to acquire ligand migration rates comparable to those observed for Mt-trHbO, confirming that ligand migration is regulated by the internal tunnel architecture as well as by water molecules stabilized in the active site.
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Affiliation(s)
- Ignacio Boron
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Juan Pablo Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Kelly S Davidge
- Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sandip Singh
- Institute of Microbial Technology, CSIR, Chandigarh, 160036, India
| | - Lesley AH Bowman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Mariana Tinajero-Trejo
- Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK
| | - Sebastián Carballal
- Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, 11100, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, 11100, Uruguay
| | - Robert K Poole
- Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK
| | - Kanak Dikshit
- Institute of Microbial Technology, CSIR, Chandigarh, 160036, India
| | - Dario A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Marcelo A Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Leonardo Boechi
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
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21
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Boron I, Bustamante JP, Davidge KS, Singh S, Bowman LAH, Tinajero-Trejo M, Carballal S, Radi R, Poole RK, Dikshit K, Estrin DA, Marti MA, Boechi L. Ligand uptake in Mycobacterium tuberculosis truncated hemoglobins is controlled by both internal tunnels and active site water molecules. F1000Res 2015; 4:22. [PMID: 26478812 PMCID: PMC4591903 DOI: 10.12688/f1000research.5921.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/19/2015] [Indexed: 06/04/2024] Open
Abstract
Mycobacterium tuberculosis, the causative agent of human tuberculosis, has two proteins belonging to the truncated hemoglobin (trHb) family. Mt-trHbN presents well-defined internal hydrophobic tunnels that allow O 2 and (•)NO to migrate easily from the solvent to the active site, whereas Mt-trHbO possesses tunnels that are partially blocked by a few bulky residues, particularly a tryptophan at position G8. Differential ligand migration rates allow Mt-trHbN to detoxify (•)NO, a crucial step for pathogen survival once under attack by the immune system, much more efficiently than Mt-trHbO. In order to investigate the differences between these proteins, we performed experimental kinetic measurements, (•)NO decomposition, as well as molecular dynamics simulations of the wild type Mt-trHbN and two mutants, VG8F and VG8W. These mutations introduce modifications in both tunnel topologies and affect the incoming ligand capacity to displace retained water molecules at the active site. We found that a single mutation allows Mt-trHbN to acquire ligand migration rates comparable to those observed for Mt-trHbO, confirming that ligand migration is regulated by the internal tunnel architecture as well as by water molecules stabilized in the active site.
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Affiliation(s)
- Ignacio Boron
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Juan Pablo Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Kelly S Davidge
- Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sandip Singh
- Institute of Microbial Technology, CSIR, Chandigarh, 160036, India
| | - Lesley AH Bowman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Mariana Tinajero-Trejo
- Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK
| | - Sebastián Carballal
- Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, 11100, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, 11100, Uruguay
| | - Robert K Poole
- Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK
| | - Kanak Dikshit
- Institute of Microbial Technology, CSIR, Chandigarh, 160036, India
| | - Dario A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Marcelo A Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Leonardo Boechi
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
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22
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Zerbetto M, Frezzato D. Towards bulk thermodynamics via non-equilibrium methods: gaseous methane as a case study. Phys Chem Chem Phys 2015; 17:1966-79. [DOI: 10.1039/c4cp03815k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The equation of state of bulk materials is achieved via thermodynamic derivatives of the free energy yielded by nonequilibrium transformations and Jarzynski equality.
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Affiliation(s)
- Mirco Zerbetto
- Dipartimento di Scienze Chimiche
- Università degli Studi di Padova
- I-35131 Padova
- Italy
| | - Diego Frezzato
- Dipartimento di Scienze Chimiche
- Università degli Studi di Padova
- I-35131 Padova
- Italy
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23
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Accelerated molecular dynamics and protein conformational change: a theoretical and practical guide using a membrane embedded model neurotransmitter transporter. Methods Mol Biol 2015; 1215:253-87. [PMID: 25330967 DOI: 10.1007/978-1-4939-1465-4_12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Molecular dynamics simulation provides a powerful and accurate method to model protein conformational change, yet timescale limitations often prevent direct assessment of the kinetic properties of interest. A large number of molecular dynamic steps are necessary for rare events to occur, which allow a system to overcome energy barriers and conformationally transition from one potential energy minimum to another. For many proteins, the energy landscape is further complicated by a multitude of potential energy wells, each separated by high free-energy barriers and each potentially representative of a functionally important protein conformation. To overcome these obstacles, accelerated molecular dynamics utilizes a robust bias potential function to simulate the transition between different potential energy minima. This straightforward approach more efficiently samples conformational space in comparison to classical molecular dynamics simulation, does not require advanced knowledge of the potential energy landscape and converges to the proper canonical distribution. Here, we review the theory behind accelerated molecular dynamics and discuss the approach in the context of modeling protein conformational change. As a practical example, we provide a detailed, step-by-step explanation of how to perform an accelerated molecular dynamics simulation using a model neurotransmitter transporter embedded in a lipid cell membrane. Changes in protein conformation of relevance to the substrate transport cycle are then examined using principle component analysis.
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24
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Nategholeslam M, Gray CG, Tomberli B. Implementation of the Forward–Reverse Method for Calculating the Potential of Mean Force Using a Dynamic Restraining Protocol. J Phys Chem B 2014; 118:14203-14. [DOI: 10.1021/jp504942t] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Mostafa Nategholeslam
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - C. G. Gray
- Guelph-Waterloo
Physics Institute and Department of Physics, University of Guelph, Guelph, Ontario, Canada
| | - Bruno Tomberli
- Department
of Physics, Capilano University, North Vancouver, British
Columbia, Canada
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25
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Petruk AA, Vergara A, Marasco D, Bikiel D, Doctorovich F, Estrin DA, Merlino A. Interaction between Proteins and Ir Based CO Releasing Molecules: Mechanism of Adduct Formation and CO Release. Inorg Chem 2014; 53:10456-62. [DOI: 10.1021/ic501498g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Ariel A. Petruk
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, University of Buenos Aires, Ciudad
Universitaria, Pab. 2, C1428EHA Buenos Aires, Argentina
| | - Alessandro Vergara
- Department
of Chemical Sciences, University of Naples Federico II, via Cintia I-80126, Napoli, Italy
- CNR Institute of Biostructures and Bioimages, Via Mezzocannone 16 I-80100, Napoli, Italy
| | - Daniela Marasco
- CNR Institute of Biostructures and Bioimages, Via Mezzocannone 16 I-80100, Napoli, Italy
- Department of Pharmacy, CIRPEB: Centro Interuniversitario
di Ricerca sui Peptidi Bioattivi- University of Naples Federico II, DFM-Scarl, Via Mezzocannone, 16 80134, Napoli, Italy
| | - Damian Bikiel
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, University of Buenos Aires, Ciudad
Universitaria, Pab. 2, C1428EHA Buenos Aires, Argentina
| | - Fabio Doctorovich
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, University of Buenos Aires, Ciudad
Universitaria, Pab. 2, C1428EHA Buenos Aires, Argentina
| | - Dario A. Estrin
- Departamento de
Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, University of Buenos Aires, Ciudad
Universitaria, Pab. 2, C1428EHA Buenos Aires, Argentina
| | - Antonello Merlino
- Department
of Chemical Sciences, University of Naples Federico II, via Cintia I-80126, Napoli, Italy
- CNR Institute of Biostructures and Bioimages, Via Mezzocannone 16 I-80100, Napoli, Italy
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26
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Bustamante JP, Abbruzzetti S, Marcelli A, Gauto D, Boechi L, Bonamore A, Boffi A, Bruno S, Feis A, Foggi P, Estrin DA, Viappiani C. Ligand uptake modulation by internal water molecules and hydrophobic cavities in hemoglobins. J Phys Chem B 2014; 118:1234-45. [PMID: 24410478 DOI: 10.1021/jp410724z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Internal water molecules play an active role in ligand uptake regulation, since displacement of retained water molecules from protein surfaces or cavities by incoming ligands can promote favorable or disfavorable effects over the global binding process. Detection of these water molecules by X-ray crystallography is difficult given their positional disorder and low occupancy. In this work, we employ a combination of molecular dynamics simulations and ligand rebinding over a broad time range to shed light into the role of water molecules in ligand migration and binding. Computational studies on the unliganded structure of the thermostable truncated hemoglobin from Thermobifida fusca (Tf-trHbO) show that a water molecule is in the vicinity of the iron heme, stabilized by WG8 with the assistance of YCD1, exerting a steric hindrance for binding of an exogenous ligand. Mutation of WG8 to F results in a significantly lower stabilization of this water molecule and in subtle dynamical structural changes that favor ligand binding, as observed experimentally. Water is absent from the fully hydrophobic distal cavity of the triple mutant YB10F-YCD1F-WG8F (3F), due to the lack of residues capable of stabilizing it nearby the heme. In agreement with these effects on the barriers for ligand rebinding, over 97% of the photodissociated ligands are rebound within a few nanoseconds in the 3F mutant case. Our results demonstrate the specific involvement of water molecules in shaping the energetic barriers for ligand migration and binding.
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Affiliation(s)
- Juan P Bustamante
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires , Buenos Aires, Argentina
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27
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Abbruzzetti S, Spyrakis F, Bidon-Chanal A, Luque FJ, Viappiani C. Ligand migration through hemeprotein cavities: insights from laser flash photolysis and molecular dynamics simulations. Phys Chem Chem Phys 2013; 15:10686-701. [PMID: 23733145 DOI: 10.1039/c3cp51149a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The presence of cavities and tunnels in the interior of proteins, in conjunction with the structural plasticity arising from the coupling to the thermal fluctuations of the protein scaffold, has profound consequences on the pathways followed by ligands moving through the protein matrix. In this perspective we discuss how quantitative analysis of experimental rebinding kinetics from laser flash photolysis, trapping of unstable conformational states by embedding proteins within the nanopores of silica gels, and molecular simulations can synergistically converge to gain insight into the migration mechanism of ligands. We show how the evaluation of the free energy landscape for ligand diffusion based on the outcome of computational techniques can assist the definition of sound reaction schemes, leading to a comprehensive understanding of the broad range of chemical events and time scales that encompass the transport of small ligands in hemeproteins.
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Affiliation(s)
- Stefania Abbruzzetti
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, viale delle Scienze 7A, 43124, Parma, Italy
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28
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Oliveira A, Allegri A, Bidon-Chanal A, Knipp M, Roitberg AE, Abbruzzetti S, Viappiani C, Luque FJ. Kinetics and computational studies of ligand migration in nitrophorin 7 and its Δ1-3 mutant. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1711-21. [PMID: 23624263 DOI: 10.1016/j.bbapap.2013.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 03/25/2013] [Accepted: 04/11/2013] [Indexed: 11/18/2022]
Abstract
Nitrophorins (NPs) are nitric oxide (NO)-carrying heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus. Though NP7 exhibits a large sequence resemblance with other NPs, two major differential features are the ability to interact with negatively charged cell surfaces and the presence of a specific N-terminus composed of three extra residues (Leu1-Pro2-Gly3). The aim of this study is to examine the influence of the N-terminus on the ligand binding, and the topological features of inner cavities in closed and open states of NP7, which can be associated to the protein structure at low and high pH, respectively. Laser flash photolysis measurements of the CO rebinding kinetics to NP7 and its variant NP7(Δ1-3), which lacks the three extra residues at the N-terminus, exhibit a similar pattern and support the existence of a common kinetic mechanism for ligand migration and binding. This is supported by the existence of a common topology of inner cavities, which consists of two docking sites in the heme pocket and a secondary site at the back of the protein. The ligand exchange between these cavities is facilitated by an additional site, which can be transiently occupied by the ligand in NP7, although it is absent in NP4. These features provide a basis to explain the enhanced internal gas hosting capacity found experimentally in NP7 and the absence of ligand rebinding from secondary sites in NP4. The current data allow us to speculate that the processes of docking to cell surfaces and NO release may be interconnected in NP7, thereby efficiently releasing NO into a target cell. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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Affiliation(s)
- Ana Oliveira
- Departament de Fisicoquímica and Institut de Biomedicina, Universitat de Barcelona, Spain
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29
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Zhang Y, Liu L, Wu L, Li S, Li F, Li Z. Theoretical investigation on the diatomic ligand migration process and ligand binding properties in non-O2-binding H-NOX domain. Proteins 2013; 81:1363-76. [PMID: 23504767 DOI: 10.1002/prot.24279] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 02/08/2013] [Accepted: 02/23/2013] [Indexed: 01/26/2023]
Abstract
The Nostoc sp (Ns) H-NOX (heme-nitric oxide or OXygen-binding) domain shares 35% sequence identity with soluble guanylate cyclase (sGC) and exhibits similar ligand binding property with the sGC. Previously, our molecular dynamic (MD) simulation work identified that there exists a Y-shaped tunnel system hosted in the Ns H-NOX interior, which servers for ligand migration. The tunnels were then confirmed by Winter et al. [PNAS 2011;108(43):E 881-889] recently using x-ray crystallography with xenon pressured conditions. In this work, to further investigate how the protein matrix of Ns H-NOX modulates the ligand migration process and how the distal residue composition affects the ligand binding prosperities, the free energy profiles for nitric oxide (NO), carbon monooxide (CO), and O2 migration are explored using the steered MDs simulation and the ligand binding energies are calculated using QM/MM schemes. The potential of mean force profiles suggest that the longer branch of the tunnel would be the most favorable route for NO migration and a second NO trapping site other than the distal heme pocket along this route in the Ns H-NOX was identified. On the contrary, CO and O2 would prefer to diffuse via the shorter branch of the tunnel. The QM/MM (quantum mechanics/molecular mechanics) calculations suggest that the hydrophobic distal pocket of Ns H-NOX would provide an approximately vacuum environment and the ligand discrimination would be determined by the intrinsic binding properties of the diatomic gas ligand to the heme group.
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Affiliation(s)
- Yuebin Zhang
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Chang Chun 130012, People's Republic of China
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30
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Small ligand-globin interactions: reviewing lessons derived from computer simulation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1722-38. [PMID: 23470499 DOI: 10.1016/j.bbapap.2013.02.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/22/2013] [Accepted: 02/26/2013] [Indexed: 11/24/2022]
Abstract
In this work we review the application of classical and quantum-mechanical atomistic computer simulation tools to the investigation of small ligand interaction with globins. In the first part, studies of ligand migration, with its connection to kinetic association rate constants (kon), are presented. In the second part, we review studies for a variety of ligands such as O2, NO, CO, HS(-), F(-), and NO2(-) showing how the heme structure, proximal effects, and the interactions with the distal amino acids can modulate protein ligand binding. The review presents mainly results derived from our previous works on the subject, in the context of other theoretical and experimental studies performed by others. The variety and extent of the presented data yield a clear example of how computer simulation tools have, in the last decade, contributed to our deeper understanding of small ligand interactions with globins. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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31
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Mukhi N, Dhindwal S, Uppal S, Kumar P, Kaur J, Kundu S. X-ray crystallographic structural characteristics of Arabidopsis hemoglobin I and their functional implications. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1944-56. [PMID: 23485912 DOI: 10.1016/j.bbapap.2013.02.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/16/2013] [Accepted: 02/19/2013] [Indexed: 11/24/2022]
Abstract
Genome of the model dicot flowering plant, Arabidopsis thaliana, a popular tool for understanding molecular biology of plant physiology, encodes all three classes of plant hemoglobins that differ in their sequence, ligand binding and spectral properties. As such these globins are of considerable attention. Crystal structures of few members of plant class I nonsymbiotic hemoglobin have been described earlier. Here we report the crystal structure of Arabidopsis class I hemoglobin (AHb1) to 2.2Ǻ and compare its key features with the structures of similar nonsymbiotic hemoglobin from other species. Crystal structure of AHb1 is homologous to the related members with similar globin fold and heme pocket architecture. The structure is homodimeric in the asymmetric unit with both distal and proximal histidines coordinating to the heme iron atom. Residues lining the dimeric interface are also conserved in AHb1 with the exception of additional electrostatic interaction between H112 and E113 of each subunit and that involving Y119 through two water molecules. In addition, differences in heme pocket non-covalent interactions, a novel Ser residue at F7 position, Xe binding site variability, internal cavity topology differences, CD loop conformation and stability and other such properties might explain kinetic variability in AHb1. Detailed cavity analysis of AHb1 showed the presence of a novel long tunnel connecting the distal pockets of both the monomers. Presence of such tunnel, along with conformational heterogeneity observed in the two chains, might suggest cooperative ligand binding and support its role in NO scavenging. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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Affiliation(s)
- Nitika Mukhi
- Department of Genetics, University of Delhi South Campus, New Delhi, India
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32
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Ferreiro DN, Boechi L, Estrin DA, Martí MA. The key role of water in the dioxygenase function of Escherichia coli flavohemoglobin. J Inorg Biochem 2012; 119:75-84. [PMID: 23220591 DOI: 10.1016/j.jinorgbio.2012.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
Flavohemoglobins (FHbs) are members of the globin superfamily, widely distributed among prokaryotes and eukaryotes that have been shown to carry out nitric oxide dioxygenase (NOD) activity. In prokaryotes, such as Escherichia coli, NOD activity is a defence mechanism against the NO release by the macrophages of the hosts' immune system during infection. Because of that, FHbs have been studied thoroughly and several drugs have been developed in an effort to fight infectious processes. Nevertheless, the protein's structural determinants involved in the NOD activity are still poorly understood. In this context, the aim of the present work is to unravel the molecular basis of FHbs structural dynamics-to-function relationship using state of the art computer simulation tools. In an effort to fulfill this goal, we studied three key processes that determine NOD activity, namely i) ligand migration into the active site ii) stabilization of the coordinated oxygen and iii) intra-protein electron transfer (ET). Our results allowed us to determine key factors related to all three processes like the presence of a long hydrophobic tunnel for ligand migration, the presence of a water mediated hydrogen bond to stabilize the coordinated oxygen and therefore achieve a high affinity, and the best possible ET paths between the FAD and the heme, where water molecules play an important role. Taken together the presented results close an important gap in our understanding of the wide and diverse globin structural-functional relationships.
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Affiliation(s)
- Dardo N Ferreiro
- Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE-CONICET, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
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33
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Marcelli A, Abbruzzetti S, Bustamante JP, Feis A, Bonamore A, Boffi A, Gellini C, Salvi PR, Estrin DA, Bruno S, Viappiani C, Foggi P. Following ligand migration pathways from picoseconds to milliseconds in type II truncated hemoglobin from Thermobifida fusca. PLoS One 2012; 7:e39884. [PMID: 22792194 PMCID: PMC3391200 DOI: 10.1371/journal.pone.0039884] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 05/28/2012] [Indexed: 11/18/2022] Open
Abstract
CO recombination kinetics has been investigated in the type II truncated hemoglobin from Thermobifida fusca (Tf-trHb) over more than 10 time decades (from 1 ps to ∼100 ms) by combining femtosecond transient absorption, nanosecond laser flash photolysis and optoacoustic spectroscopy. Photolysis is followed by a rapid geminate recombination with a time constant of ∼2 ns representing almost 60% of the overall reaction. An additional, small amplitude geminate recombination was identified at ∼100 ns. Finally, CO pressure dependent measurements brought out the presence of two transient species in the second order rebinding phase, with time constants ranging from ∼3 to ∼100 ms. The available experimental evidence suggests that the two transients are due to the presence of two conformations which do not interconvert within the time frame of the experiment. Computational studies revealed that the plasticity of protein structure is able to define a branched pathway connecting the ligand binding site and the solvent. This allowed to build a kinetic model capable of describing the complete time course of the CO rebinding kinetics to Tf-trHb.
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Affiliation(s)
- Agnese Marcelli
- LENS, European Laboratory for Non-linear Spectroscopy, Florence, Italy.
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34
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Sgrignani J, Magistrato A. Influence of the Membrane Lipophilic Environment on the Structure and on the Substrate Access/Egress Routes of the Human Aromatase Enzyme. A Computational Study. J Chem Inf Model 2012; 52:1595-606. [DOI: 10.1021/ci300151h] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Jacopo Sgrignani
- CNR-IOM-Democritos National Simulation Center c/o International Studies for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34165 Trieste
(TS), Italy
| | - Alessandra Magistrato
- CNR-IOM-Democritos National Simulation Center c/o International Studies for Advanced Studies (SISSA/ISAS), via Bonomea 265, 34165 Trieste
(TS), Italy
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35
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Bereźniak T, Jäschke A, Smith JC, Imhof P. Stereoselection in the diels-alderase ribozyme: A molecular dynamics study. J Comput Chem 2012; 33:1603-14. [DOI: 10.1002/jcc.22993] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 03/05/2012] [Accepted: 03/18/2012] [Indexed: 01/03/2023]
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36
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Forti F, Boechi L, Bikiel D, Martí MA, Nardini M, Bolognesi M, Viappiani C, Estrin D, Luque FJ. Ligand Migration in Methanosarcina acetivorans Protoglobin: Effects of Ligand Binding and Dimeric Assembly. J Phys Chem B 2011; 115:13771-80. [DOI: 10.1021/jp208562b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Flavio Forti
- Departament de Fisicoquímica and Institut de Biomedicina, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Diagonal 643, E-08028, Barcelona, Spain
| | - Leonardo Boechi
- Departamento de Química Inorgánica, Analítica, y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Damian Bikiel
- Departamento de Química Inorgánica, Analítica, y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marcelo A. Martí
- Departamento de Química Inorgánica, Analítica, y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marco Nardini
- Dipartimento di Scienze Biomolecolari e Biotecnologie and CIMAINA, Università degli Studi di Milano, I-20131 Milano, Italy
| | - Martino Bolognesi
- Dipartimento di Scienze Biomolecolari e Biotecnologie and CIMAINA, Università degli Studi di Milano, I-20131 Milano, Italy
| | - Cristiano Viappiani
- Dipartimento di Fisica, Università degli Studi di Parma, Parma, Italy
- NEST, Istituto Nanoscienze-CNR, Italy
| | - Darío Estrin
- Departamento de Química Inorgánica, Analítica, y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
| | - F. Javier Luque
- Departament de Fisicoquímica and Institut de Biomedicina, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Diagonal 643, E-08028, Barcelona, Spain
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