Functional and structural roles of the N-terminal extension in Methanosarcina acetivorans protoglobin
| Autor: | Massimo Coletta, Martino Bolognesi, Grazia R. Tundo, Alessandra Pesce, Luc Moens, Sylvia Dewilde, Paolo Ascenzi, L. Tilleman, Marco Nardini, Laura Bertolacci, Chiara Ciaccio |
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| Přispěvatelé: | Ciaccio, C, Pesce, A, Tundo, Gr, Tilleman, L, Bertolacci, L, Dewilde, S, Moens, L, Ascenzi, Paolo, Bolognesi, M, Nardini, M, Coletta, M. |
| Rok vydání: | 2013 |
| Předmět: |
Azides
Stereochemistry Molecular Sequence Data Mutant HEMOGLOBINS Biophysics Heme Nitric Oxide Biochemistry Protein Structure Secondary Analytical Chemistry REDUCTIVE NITROSYLATION Protein Carbonylation chemistry.chemical_compound Amino Acid Sequence Settore BIO/10 Methanosarcina acetivorans Biology Molecular Biology chemistry.chemical_classification Carbon Monoxide Sequence Homology Amino Acid biology Chemistry Physics Oxygen transport Ligand (biochemistry) biology.organism_classification HEME REACTIVITY EVOLUTION Globins Globin fold Amino acid MODEL LIFE Kinetics Methanosarcina Mutation GLOBIN-COUPLED SENSORS Human medicine Oxygen binding Protein Binding |
| Zdroj: | Biochimica et biophysica acta. Proteins and proteomics 1834 (2013): 1813–1823. doi:10.1016/j.bbapap.2013.02.026 info:cnr-pdr/source/autori:Ciaccio C, Pesce A, Tundo GR, Tilleman L, Bertolacci L, Dewilde S, Moens L, Ascenzi P, Bolognesi M, Nardini M, Coletta M/titolo:Functional and structural roles of the N-terminal extension in Methanosarcina acetivorans protoglobin/doi:10.1016%2Fj.bbapap.2013.02.026/rivista:Biochimica et biophysica acta. Proteins and proteomics/anno:2013/pagina_da:1813/pagina_a:1823/intervallo_pagine:1813–1823/volume:1834 Biochimica et biophysica acta : proteins and proteomics |
| ISSN: | 1570-9639 |
| Popis: | Functional and structural properties of protoglobin from Methanosarcina acetivorans, whose Cys(101)E20 residue was mutated to Ser (MaPgb*), and of mutants missing either the first 20 N-terminal amino acids (MaPgb*-Delta N20 mutant), or the first 33 N-terminal amino acids [N-terminal loop of 20 amino acids and a 13-residue Z-helix, preceding the globin fold A-helix; (MaPgb*-Delta N20Z mutant)] have been investigated. In keeping with the MaPgb*-Delta N20 mutant crystal structure, here reported at 2.0 angstrom resolution, which shows an increased exposure of the haem propionates to the solvent, the analysis of ligand binding kinetics highlights high accessibility of ligands to the haem pocket in ferric MaPgb*-Delta N20. CO binding to ferrous MaPgb*-Delta N20 displays a marked biphasic behavior, with a fast binding process close to that observed in MaPgb* and a slow carbonylation process, characterized by a rate-limiting step. Conversely, removal of the first 33 residues induces a substantial perturbation of the overall MaPgb* structure, with loss of alpha-helical content and potential partial collapse of the protein chain. As such, ligand binding kinetics are characterized by very slow rates that are independent of ligand concentration, this being indicative of a high energy barrier for ligand access to the haem, possibly due to localized misfolding. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins. (c) 2013 Elsevier B.V. All rights reserved |
| Databáze: | OpenAIRE |
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