Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values

The sequential action of glutamine synthetase (GS) and glutamate synthase (GOGAT) in cyanobacteria allows the incorporation of ammonium into carbon skeletons. In the cyanobacterium Synechocystis sp. PCC 6803, the activity of GS is modulated by the interaction with proteins, which include a 65-residu...

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Autores: Cozza, C, Neira, JL, Florencio, FJ, Muro-Pastor, MI, Rizzuti, B
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositorio:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p12829
Acceso en línea:https://fisabio.portalinvestigacion.com/publicaciones/12829
Access Level:acceso abierto
Palabra clave:electrostatics
intrinsically disordered proteins
molecular dynamics
nuclear magnetic resonance
pK(a) values
titration
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spelling Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) valuesCozza, CNeira, JLFlorencio, FJMuro-Pastor, MIRizzuti, Belectrostaticsintrinsically disordered proteinsmolecular dynamicsnuclear magnetic resonancepK(a) valuestitrationThe sequential action of glutamine synthetase (GS) and glutamate synthase (GOGAT) in cyanobacteria allows the incorporation of ammonium into carbon skeletons. In the cyanobacterium Synechocystis sp. PCC 6803, the activity of GS is modulated by the interaction with proteins, which include a 65-residue-long intrinsically disordered protein (IDP), the inactivating factor IF7. This interaction is regulated by the presence of charged residues in both IF7 and GS. To understand how charged amino acids can affect the binding of an IDP with its target and to provide clues on electrostatic interactions in disordered states of proteins, we measured the pK(a) values of all IF7 acidic groups (Glu32, Glu36, Glu38, Asp40, Asp58, and Ser65, the backbone C-terminus) at 100 mM NaCl concentration, by using NMR spectroscopy. We also obtained solution structures of IF7 through molecular dynamics simulation, validated them on the basis of previous experiments, and used them to obtain theoretical estimates of the pKa values. Titration values for the two Asp and three Glu residues of IF7 were similar to those reported for random-coil models, suggesting the lack of electrostatic interactions around these residues. Furthermore, our results suggest the presence of helical structure at the N-terminus of the protein and of conformational changes at acidic pH values. The overall experimental and in silico findings suggest that local interactions and conformational equilibria do not play a role in determining the electrostatic features of the acidic residues of IF7.Wiley-Blackwell2017info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttps://fisabio.portalinvestigacion.com/publicaciones/12829Protein ScienceISSN: 1469896XISSNe: 09618368reponame:r-FISABIO. Repositorio Institucional de Producción Científicainstname:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)Inglésinfo:eu-repo/semantics/openAccessoai:fisabio.fundanetsuite.com:p128292026-06-11T12:45:17Z
dc.title.none.fl_str_mv Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
title Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
spellingShingle Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
Cozza, C
electrostatics
intrinsically disordered proteins
molecular dynamics
nuclear magnetic resonance
pK(a) values
titration
title_short Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
title_full Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
title_fullStr Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
title_full_unstemmed Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
title_sort Intrinsically disordered inhibitor of glutamine synthetase is a functional protein with random-coil-like pK(a) values
dc.creator.none.fl_str_mv Cozza, C
Neira, JL
Florencio, FJ
Muro-Pastor, MI
Rizzuti, B
author Cozza, C
author_facet Cozza, C
Neira, JL
Florencio, FJ
Muro-Pastor, MI
Rizzuti, B
author_role author
author2 Neira, JL
Florencio, FJ
Muro-Pastor, MI
Rizzuti, B
author2_role author
author
author
author
dc.subject.none.fl_str_mv electrostatics
intrinsically disordered proteins
molecular dynamics
nuclear magnetic resonance
pK(a) values
titration
topic electrostatics
intrinsically disordered proteins
molecular dynamics
nuclear magnetic resonance
pK(a) values
titration
description The sequential action of glutamine synthetase (GS) and glutamate synthase (GOGAT) in cyanobacteria allows the incorporation of ammonium into carbon skeletons. In the cyanobacterium Synechocystis sp. PCC 6803, the activity of GS is modulated by the interaction with proteins, which include a 65-residue-long intrinsically disordered protein (IDP), the inactivating factor IF7. This interaction is regulated by the presence of charged residues in both IF7 and GS. To understand how charged amino acids can affect the binding of an IDP with its target and to provide clues on electrostatic interactions in disordered states of proteins, we measured the pK(a) values of all IF7 acidic groups (Glu32, Glu36, Glu38, Asp40, Asp58, and Ser65, the backbone C-terminus) at 100 mM NaCl concentration, by using NMR spectroscopy. We also obtained solution structures of IF7 through molecular dynamics simulation, validated them on the basis of previous experiments, and used them to obtain theoretical estimates of the pKa values. Titration values for the two Asp and three Glu residues of IF7 were similar to those reported for random-coil models, suggesting the lack of electrostatic interactions around these residues. Furthermore, our results suggest the presence of helical structure at the N-terminus of the protein and of conformational changes at acidic pH values. The overall experimental and in silico findings suggest that local interactions and conformational equilibria do not play a role in determining the electrostatic features of the acidic residues of IF7.
publishDate 2017
dc.date.none.fl_str_mv 2017
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://fisabio.portalinvestigacion.com/publicaciones/12829
url https://fisabio.portalinvestigacion.com/publicaciones/12829
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Wiley-Blackwell
publisher.none.fl_str_mv Wiley-Blackwell
dc.source.none.fl_str_mv Protein Science
ISSN: 1469896X
ISSNe: 09618368
reponame:r-FISABIO. Repositorio Institucional de Producción Científica
instname:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
instname_str Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
reponame_str r-FISABIO. Repositorio Institucional de Producción Científica
collection r-FISABIO. Repositorio Institucional de Producción Científica
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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