A serine protease from the bovine duodenal mucosa, chymotrypsin-like duodenase.
Eur J Biochem
; 255(2): 501-7, 1998 Jul 15.
Article
em En
| MEDLINE
| ID: mdl-9716393
ABSTRACT
Chymotrypsin-like duodenase (ChlD), a new protease from the bovine duodenum mucosa was isolated and purified. The enzyme molecule is a single chain (25 kDa); the native enzyme is a monomer with an isoelectric point > 10.0. ChlD displays the chymotrypsin-like activity and cleaves 4-nitroanilide substrates of chymotrypsin, chymases and cathepsin G. ChlD hydrolyzes its best substrate 2-N-succinylvalylprolylphenylalanine 4-nitroanilide with k(cat) of 2.8 s(-1) and catalytic efficiency k(cat)/Km of 2300 M(-1) s(-1). The enzyme is stable with a pH range of 3-10 and exhibits the maximum activity at pH 8-10. ChlD is irreversibly inhibited by diisopropylphosphofluoridate and phenylmethanesulfonyl fluoride, which is indicative of an active-site serine in this protease. Alpha-N-tosyl-L-phenylalanine chloromethane, a specific reagent for a catalytically active His, markedly inhibited ChlD. The enzyme activity was strongly inhibited by several natural inhibitors of serine proteases (from soybean, potato, Lima bean, kidney bean). The N-terminal sequence of the native ChlD (23 amino acids) shows high similarity, but not identity, to those of duodenase, granzymes, chymases and cathepsin G.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Serina Endopeptidases
/
Mucosa Intestinal
Limite:
Animals
Idioma:
En
Revista:
Eur J Biochem
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Federação Russa