Intracellular coupling of the heavy chain of pre-alpha-inhibitor to chondroitin sulfate.
J Biol Chem
; 277(16): 13578-82, 2002 Apr 19.
Article
em En
| MEDLINE
| ID: mdl-11827976
ABSTRACT
Pre-alpha-inhibitor is a serum protein consisting of two polypeptides, the heavy chain and bikunin, covalently linked through an ester bond between the chondroitin sulfate chain of bikunin and the alpha-carboxyl group of the carboxyl-terminal residue of the heavy chain. The heavy chain is synthesized with a carboxyl-terminal extension, which is cleaved off just before the link to bikunin is formed. Our earlier studies indicate that this extension mediates the cleavage, and we have now found that a short segment on the amino-terminal side of the cleavage site is also required for the reaction. Furthermore, we previously showed that coexpression of the heavy chain precursor and bikunin in COS-1 cells leads to linkage, and we have now used this system to identify a His residue in the carboxyl-terminal extension that is specifically required for the intracellular coupling of the two proteins. In addition, we have shown that another chondroitin sulfate-containing protein, decorin, will also form a complex with the heavy chain, as will free chondroitin sulfate chains. These results suggest that in vivo there might be other, as yet unknown, chondroitin sulfate-containing polypeptides linked to the heavy chain.
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Base de dados:
MEDLINE
Assunto principal:
Precursores de Proteínas
/
Inibidor da Tripsina de Soja de Kunitz
/
Inibidores da Tripsina
/
Sulfatos de Condroitina
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Suécia