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Titolo:
SUBSTRATE-SPECIFICITY OF TISSUE-TYPE PLASMINOGEN-ACTIVATOR - CHARACTERIZATION OF THE FIBRIN INDEPENDENT SPECIFICITY OF T-PA FOR PLASMINOGEN
Autore:
MADISON EL; COOMBS GS; COREY DR;
Indirizzi:
SCRIPPS CLIN & RES INST,DEPT VASC BIOL LA JOLLA CA 92037 UNIV TEXAS,SW MED CTR,HOWARD HUGHES MED INST,DEPT PHARMACOL DALLAS TX75235
Titolo Testata:
The Journal of biological chemistry
fascicolo: 13, volume: 270, anno: 1995,
pagine: 7558 - 7562
SICI:
0021-9258(1995)270:13<7558:SOTP-C>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
GROWTH-FACTOR PRECURSOR; STRUCTURAL DOMAINS; ESCHERICHIA-COLI; B-CHAIN; SEQUENCE; PROTEIN; FIBRONECTIN; PROTHROMBIN; INVOLVEMENT; THROMBIN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
43
Recensione:
Indirizzi per estratti:
Citazione:
E.L. Madison et al., "SUBSTRATE-SPECIFICITY OF TISSUE-TYPE PLASMINOGEN-ACTIVATOR - CHARACTERIZATION OF THE FIBRIN INDEPENDENT SPECIFICITY OF T-PA FOR PLASMINOGEN", The Journal of biological chemistry, 270(13), 1995, pp. 7558-7562

Abstract

Tissue-type plasminogen activator (t-PA) is a remarkably specific protease: the only known substrate of this enzyme in vivo is a single peptide bond (Arg(560)-Va1(561)) within the proenzyme plasminogen. Part of the substrate specificity of t-PA is due to a ternary interaction between fibrin, BPA, and plasminogen which reduces the K-m of t-PA for plasminogen by a factor of 440. However, even in the absence of fibrin,t-PA continues to hydrolyze plasminogen more rapidly than does trypsin, a homologous serine protease. We have measured the extent of the specificity of t-PA for plasminogen by assaying t-PA and trypsin toward substrates modeled after the peptide sequence in plasminogen surrounding Ar-960-Val(561). Surprisingly, t-PA hydrolyzes these substrates with kappa(cat)/K-m values which are 28,000-210,000-fold lower than thoseobtained using trypsin. Both the high activity toward plasminogen andthe low activity toward peptides are also exhibited by the isolated protease domain. This suggests that the protease domain, in spite of its high homology to the nonspecific enzyme trypsin, is inherently specific for recognition of one or more structural features displayed by native plasminogen.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/12/20 alle ore 08:08:33