Data/hora: 11/06/2024 02:28:28

Provedor de dados: | 56
País: | Brazil
Título: | A study of the interaction between Helicobacter pylori and components of the human fibrinolytic system
Autores: | Yarzábal,A.; Avilán,L.; Hoelzl,K.; Muñoz,M. de; Puig,J.; Kansau,I.
Data: | 2000-09-01
Ano: | 2000
Palavras-chave: | Helicobacter pylori; Plasminogen; T-PA; Urokinase; Plasminogen activation.
Resumo: | The interaction of plasminogen, tissue plasminogen activator (t-PA) and urokinase with a clinical strain of Helicobacter pylori was studied. Plasminogen bound to the surface of H. pylori cells in a concentration-dependent manner and could be activated to the enzymatic form, plasmin, by t-PA. Affinity chromatography assays revealed a plasminogen-binding protein of 58.9 kDa in water extracts of surface proteins. Surface-associated plasmin activity, detected with the chromogenic substrate CBS 00.65, was observed only when plasminogen and an exogenous activator were added to the cell suspension. The two physiologic plasminogen activators, t-PA and urokinase, were also shown to bind to and remain active on the surface of bacterial cells. epsilon-Aminocaproic acid caused partial inhibition of t-PA binding, suggesting that the kringle 2 structure of this activator is involved in the interaction with surface receptors. The activation of plasminogen by t-PA, but not urokinase, strongly depended on the presence of cells and a 25-fold enhancer effect on the initial velocity of activation by t-PA compared to urokinase was established. Furthermore, a relationship between cell concentration and the initial velocity of activation was demonstrated. These findings support the concept that plasminogen activation by t-PA on the bacterial surface is a surface-dependent reaction which offers catalytic advantages.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000900004
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2000000900004
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.33 n.9 2000
Fonte: | info:eu-repo/semantics/openAccess