Intermediate conformation between native ß-sheet and non-native α-helix is a precursor of trifluoroethanol-induced aggregation of human carbonic anhydrase-II.
Biochem Biophys Res Commun
; 449(1): 126-31, 2014 Jun 20.
Article
em En
| MEDLINE
| ID: mdl-24813993
ABSTRACT
In the present work, we examined the correlation between 2,2,2-trifluoroethanol (TFE)-induced conformational transitions of human carbonic anhydrase II (HCAII) and its aggregation propensity. Circular dichroism data indicates that protein undergoes a transition from ß-sheet to α-helix on addition of TFE. The protein was found to aggregate maximally at moderate concentration of TFE at which it exists somewhere between ß-sheet and α-helix, probably in extended non-native ß-sheet conformation. Thioflavin-T (ThT) and Congo-Red (CR) assays along with fluorescence microscopy and transmission electron microscopy (TEM) data suggest that the protein aggregates induced by TFE possess amyloid-like features. Anilino-8-naphthalene sulfonate (ANS) binding studies reveal that the exposure of hydrophobic surface(s) was maximum in intermediate conformation. Our study suggests that the exposed hydrophobic surface and/or the disruption of the structural features protecting a ß-sheet protein might be the major reason(s) for the high aggregation propensity of non-native intermediate conformation of HCAII.
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Base de dados:
MEDLINE
Assunto principal:
Trifluoretanol
/
Anidrase Carbônica II
Limite:
Humans
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article