Artículo
The E. coli thioredoxin folding mechanism: the key role of the C-terminal helix
Vazquez, Diego Sebastian; Sánchez Miguel, Ignacio Enrique
; Garrote López, Ana Marcela
; Sica, Mauricio Pablo
; Santos, Javier
Fecha de publicación:
02/2015
Editorial:
Elsevier Science
Revista:
Biochimica Et Biophysica Acta-proteins And Proteomics
ISSN:
1570-9639
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
In this work, the unfolding mechanism of oxidized Escherichia coli thioredoxin (EcTRX) was investigated experimentally and computationally. We characterized seven point mutants distributed along the C-terminal α-helix (CTH) and the preceding loop. The mutations destabilized the protein against global unfolding while leaving the native structure unchanged. Global analysis of the unfolding kinetics of all variants revealed a linear unfolding route with a high-energy on-pathway intermediate state flanked by two transition state ensembles TSE1 and TSE2. The experiments show that CTH is mainly unfolded in TSE1 and the intermediate and becomes structured in TSE2. Structure-based molecular dynamics are in agreement with these experiments and provide protein-wide structural information on transient states. In our model, EcTRX folding starts with structure formation in the β-sheet, while the protein helices coalesce later. As a whole, our results indicate that the CTH is a critical module in the folding process, restraining a heterogeneous intermediate ensemble into a biologically active native state and providing the native protein with thermodynamic and kinetic stability.
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Articulos(IQUIBICEN)
Articulos de INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CS. EXACTAS Y NATURALES
Articulos de INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CS. EXACTAS Y NATURALES
Articulos(IQUIFIB)
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Citación
Vazquez, Diego Sebastian; Sánchez Miguel, Ignacio Enrique; Garrote López, Ana Marcela; Sica, Mauricio Pablo; Santos, Javier; The E. coli thioredoxin folding mechanism: the key role of the C-terminal helix; Elsevier Science; Biochimica Et Biophysica Acta-proteins And Proteomics; 1854; 2; 2-2015; 127-137
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