A study of the interaction between Helicobacter pylori and components of the human fibrinolytic system
| Autor: | A. Yarzábal, L. Avilán, K. Hoelzl, M. de Muñoz, J. Puig, I. Kansau |
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| Jazyk: | angličtina |
| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Brazilian Journal of Medical and Biological Research, Vol 33, Iss 9, Pp 1015-1021 (2000) |
| Druh dokumentu: | article |
| ISSN: | 0100-879X 1414-431X |
| DOI: | 10.1590/S0100-879X2000000900004 |
| Popis: | 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. |
| Databáze: | Directory of Open Access Journals |
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