Secondary structure and thermostability of the photosystem II manganese-stabilizing protein of the thermophilic cyanobacterium Synechococcus elongatus.
Biochim Biophys Acta
; 1297(2): 167-70, 1996 Oct 17.
Article
em En
| MEDLINE
| ID: mdl-8917618
ABSTRACT
The secondary structure of the manganese-stabilizing protein of the thermophilic cyanobacterium Synechococcus elongatus in solution was investigated by Fourier-transform infrared (FT-IR) and circular dichroism (CD) spectroscopies. Both methods showed a high proportion of disordered structure (40-43%) and a relatively small amount of beta-sheet (23-24%) and alpha-helix (17-19%). The conformation of the protein remained essentially unchanged at temperatures up to 70 degrees C. Unfolding of the protein occurred at higher temperatures and FT-IR spectroscopy revealed that beta-sheet was more strongly unfolded than alpha-helix at 76 degrees C. The protein largely lost the ordered secondary structures at 90 degrees C, but, when cooled down to 30 degrees C, regained its original conformation. Thus, the cyanobacterial protein is very thermostable and its denaturation at an extremely high temperature is reversible.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Estabilidade Enzimática
/
Proteínas
/
Cianobactérias
/
Estrutura Secundária de Proteína
/
Complexo de Proteína do Fotossistema II
/
Manganês
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Japão