Plant serine proteinase inhibitors. Structure and biochemical applications on plasma kallikrein and related enzymes.
Immunopharmacology
; 32(1-3): 62-6, 1996 May.
Article
em En
| MEDLINE
| ID: mdl-8796268
ABSTRACT
The action of two Bowman-Birk and several plant Kunitz-type inhibitors were studied on trypsin, chymotrypsin, plasma kallikrein and factor XII. The primary structure of some of them was completely defined. The results showed that the Bowman-Birk type inhibitors, although potent inhibitors for trypsin (Ki in the range of 1-2 nM), are not able to inhibit plasma kallikrein. Factor XII (Ki = 1.4 microM) and chymotrypsin (Ki = 5.0 nM) are inhibited by Torresea cearensis trypsin inhibitor (TcTI) but not by Dioclea glabra trypsin inhibitor (DgTI). Both inhibitors reactive site regions are highly homologous, and the amino acid residues in P1 position are the same, Lys and His; major differences are in the charge of the C-terminal portion of the molecules. The studied Kunitz-type inhibitors were all able to inhibit plasma kallikrein (Ki between 4 and 80 nM), with the exception of Schizolobium parahyba chymotrypsin inhibitor (SpCI), that is specific for chymotrypsin. All Kunitz-type inhibitors inactivate chymotrypsin, but with a dissociation constant in the range of 0.1 to 0.6 microM. Factor XIIf is inhibited with Ki in the range of 0.1 microM. Bauhinia bauhinioides trypsin inhibitor (BbTI) did not promote factor XIIf inhibition. The Kunitz-type inhibitors are a highly homologous, sharing 60% identity in the N-terminal portion of the loop containing the reactive site, and 28.6% identity in the C-terminal portion of the same loop.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Calicreínas
/
Inibidores de Serina Proteinase
/
Inibidor da Tripsina de Soja de Bowman-Birk
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Immunopharmacology
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS