ADP-insensitive phosphoenzyme intermediate of sarcoplasmic reticulum Ca(2+)-ATPase has a compact conformation resistant to proteinase K, V8 protease and trypsin.
FEBS Lett
; 489(2-3): 277-82, 2001 Feb 02.
Article
em En
| MEDLINE
| ID: mdl-11165264
ABSTRACT
Sarcoplasmic reticulum Ca(2+)-ATPase was digested with proteinase K, V8 protease and trypsin in the absence of Ca(2+). Unphosphorylated enzyme was rapidly degraded. In contrast, ADP-insensitive phosphoenzyme formed with P(i) and phosphorylated state analogues produced by the binding of F(-) or orthovanadate, were almost completely resistant to the proteolysis except for tryptic cleavage at the T1 site (Arg(505)). The results indicate that the phosphoenzyme and its analogues have a very compact form in the cytoplasmic region, being consistent with large domain motions (gathering of three cytoplasmic domains). Results further show that the structure of the enzyme with bound decavanadate is very similar to ADP-insensitive phosphoenzyme. Thapsigargin did not affect the changes in digestion time course induced by the formation of the phosphorylated state analogues.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfoproteínas
/
Retículo Sarcoplasmático
/
Serina Endopeptidases
/
ATPases Transportadoras de Cálcio
Limite:
Animals
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Japão