A study of the interaction between Helicobacter pylori and components of the human fibrinolytic system
Braz. j. med. biol. res
; 33(9): 1015-21, Sept. 2000.
Artigo
em Inglês
| LILACS
| ID: lil-267977
Biblioteca responsável:
BR1.1
ABSTRACT
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
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Ativadores de Plasminogênio
/
Helicobacter pylori
/
Ativador de Plasminogênio Tecidual
/
Fibrinolíticos
Limite:
Humanos
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2000
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Venezuela
Instituição/País de afiliação:
Universidad de Los Andes/VE