Three-dimensional solution structure and stability of thioredoxin m from spinach

Proton NMR spectral resonances of thioredoxin m from spinach have been assigned, and its solution structure has been determined on the basis of 1156 nuclear Overhauser effect- (NOE-) derived distance constraints by using restrained molecular dynamics calculations. The average pairwise root-mean-squa...

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Autor principal: de Prat Gay, Gonzalo
Publicado: 2001
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v40_n50_p15246_Neira
http://hdl.handle.net/20.500.12110/paper_00062960_v40_n50_p15246_Neira
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spelling paper:paper_00062960_v40_n50_p15246_Neira2023-06-08T14:30:38Z Three-dimensional solution structure and stability of thioredoxin m from spinach de Prat Gay, Gonzalo Three-dimensional solutions Crystal structure Crystallization Dimers Extrapolation Free energy Ion exchange Molecular dynamics Nuclear magnetic resonance spectroscopy pH effects Protons Proteins thioredoxin thioredoxin m unclassified drug article circular dichroism crystal structure molecular dynamics nonhuman nuclear magnetic resonance priority journal protein conformation protein denaturation protein stability protein tertiary structure spinach structure analysis Amides Amino Acid Sequence Circular Dichroism Crystallization Crystallography, X-Ray Dimerization Drug Stability Magnetic Resonance Spectroscopy Models, Molecular Molecular Sequence Data Oxidation-Reduction Protein Folding Protein Structure, Secondary Protons Solutions Spinacia oleracea Thermodynamics Thioredoxin Spinacia oleracea Proton NMR spectral resonances of thioredoxin m from spinach have been assigned, and its solution structure has been determined on the basis of 1156 nuclear Overhauser effect- (NOE-) derived distance constraints by using restrained molecular dynamics calculations. The average pairwise root-mean-square deviation (RMSD) for the 25 best NMR structures for the backbone was 1.0 ± 1, when the structurally well-defined residues were considered. The N- and C-terminal segments (1-13 and 118-119) and residues 41-49, comprising the active site, are highly disordered. At the time of concluding this work, a crystal structure of this protein was reported, in which thioredoxin m was found to crystallize as noncovalent dimers. Although the solution and crystal structures are very similar, no evidence was found about the existence of dimers in solution, thus confirming that dimerization is not needed for the regulatory activity of thioredoxin m. The spinach thioredoxin m does not unfold by heat in the range 25-85 °C, as revealed by thermal circular dichroic (CD) measurements. However, its unfolding free energy (9.1 ± 0.8 kcal mol-1, at pH 5.3 and 25 °C) could be determined by extrapolating the free energy values obtained at different concentrations of guanidinium chloride (GdmC). The folding-unfolding process is two-state as indicated by the coincidence of the CD denaturation curves obtained at far and near UV. The H/D exchange behavior of backbone amide protons was analyzed. The slowest-exchanging protons, requiring a global-unfolding mechanism in order to exchange, are those from β2, β3, and β4, the central strands of the β-sheet, which constitute the main element of the core of the protein. The free energies obtained from exchange measurements of protons belonging to the α-helices are lower than those derived from GdmCdenaturation studies, indicating that those protons exchange by local-unfolding mechanisms. Fil:De Prat-Gay, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2001 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v40_n50_p15246_Neira http://hdl.handle.net/20.500.12110/paper_00062960_v40_n50_p15246_Neira
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Three-dimensional solutions
Crystal structure
Crystallization
Dimers
Extrapolation
Free energy
Ion exchange
Molecular dynamics
Nuclear magnetic resonance spectroscopy
pH effects
Protons
Proteins
thioredoxin
thioredoxin m
unclassified drug
article
circular dichroism
crystal structure
molecular dynamics
nonhuman
nuclear magnetic resonance
priority journal
protein conformation
protein denaturation
protein stability
protein tertiary structure
spinach
structure analysis
Amides
Amino Acid Sequence
Circular Dichroism
Crystallization
Crystallography, X-Ray
Dimerization
Drug Stability
Magnetic Resonance Spectroscopy
Models, Molecular
Molecular Sequence Data
Oxidation-Reduction
Protein Folding
Protein Structure, Secondary
Protons
Solutions
Spinacia oleracea
Thermodynamics
Thioredoxin
Spinacia oleracea
spellingShingle Three-dimensional solutions
Crystal structure
Crystallization
Dimers
Extrapolation
Free energy
Ion exchange
Molecular dynamics
Nuclear magnetic resonance spectroscopy
pH effects
Protons
Proteins
thioredoxin
thioredoxin m
unclassified drug
article
circular dichroism
crystal structure
molecular dynamics
nonhuman
nuclear magnetic resonance
priority journal
protein conformation
protein denaturation
protein stability
protein tertiary structure
spinach
structure analysis
Amides
Amino Acid Sequence
Circular Dichroism
Crystallization
Crystallography, X-Ray
Dimerization
Drug Stability
Magnetic Resonance Spectroscopy
Models, Molecular
Molecular Sequence Data
Oxidation-Reduction
Protein Folding
Protein Structure, Secondary
Protons
Solutions
Spinacia oleracea
Thermodynamics
Thioredoxin
Spinacia oleracea
de Prat Gay, Gonzalo
Three-dimensional solution structure and stability of thioredoxin m from spinach
topic_facet Three-dimensional solutions
Crystal structure
Crystallization
Dimers
Extrapolation
Free energy
Ion exchange
Molecular dynamics
Nuclear magnetic resonance spectroscopy
pH effects
Protons
Proteins
thioredoxin
thioredoxin m
unclassified drug
article
circular dichroism
crystal structure
molecular dynamics
nonhuman
nuclear magnetic resonance
priority journal
protein conformation
protein denaturation
protein stability
protein tertiary structure
spinach
structure analysis
Amides
Amino Acid Sequence
Circular Dichroism
Crystallization
Crystallography, X-Ray
Dimerization
Drug Stability
Magnetic Resonance Spectroscopy
Models, Molecular
Molecular Sequence Data
Oxidation-Reduction
Protein Folding
Protein Structure, Secondary
Protons
Solutions
Spinacia oleracea
Thermodynamics
Thioredoxin
Spinacia oleracea
description Proton NMR spectral resonances of thioredoxin m from spinach have been assigned, and its solution structure has been determined on the basis of 1156 nuclear Overhauser effect- (NOE-) derived distance constraints by using restrained molecular dynamics calculations. The average pairwise root-mean-square deviation (RMSD) for the 25 best NMR structures for the backbone was 1.0 ± 1, when the structurally well-defined residues were considered. The N- and C-terminal segments (1-13 and 118-119) and residues 41-49, comprising the active site, are highly disordered. At the time of concluding this work, a crystal structure of this protein was reported, in which thioredoxin m was found to crystallize as noncovalent dimers. Although the solution and crystal structures are very similar, no evidence was found about the existence of dimers in solution, thus confirming that dimerization is not needed for the regulatory activity of thioredoxin m. The spinach thioredoxin m does not unfold by heat in the range 25-85 °C, as revealed by thermal circular dichroic (CD) measurements. However, its unfolding free energy (9.1 ± 0.8 kcal mol-1, at pH 5.3 and 25 °C) could be determined by extrapolating the free energy values obtained at different concentrations of guanidinium chloride (GdmC). The folding-unfolding process is two-state as indicated by the coincidence of the CD denaturation curves obtained at far and near UV. The H/D exchange behavior of backbone amide protons was analyzed. The slowest-exchanging protons, requiring a global-unfolding mechanism in order to exchange, are those from β2, β3, and β4, the central strands of the β-sheet, which constitute the main element of the core of the protein. The free energies obtained from exchange measurements of protons belonging to the α-helices are lower than those derived from GdmCdenaturation studies, indicating that those protons exchange by local-unfolding mechanisms.
author de Prat Gay, Gonzalo
author_facet de Prat Gay, Gonzalo
author_sort de Prat Gay, Gonzalo
title Three-dimensional solution structure and stability of thioredoxin m from spinach
title_short Three-dimensional solution structure and stability of thioredoxin m from spinach
title_full Three-dimensional solution structure and stability of thioredoxin m from spinach
title_fullStr Three-dimensional solution structure and stability of thioredoxin m from spinach
title_full_unstemmed Three-dimensional solution structure and stability of thioredoxin m from spinach
title_sort three-dimensional solution structure and stability of thioredoxin m from spinach
publishDate 2001
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00062960_v40_n50_p15246_Neira
http://hdl.handle.net/20.500.12110/paper_00062960_v40_n50_p15246_Neira
work_keys_str_mv AT depratgaygonzalo threedimensionalsolutionstructureandstabilityofthioredoxinmfromspinach
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