Effects of histidine-proline-rich glycoprotein on plasminogen activation in solution and on surfaces.
Blood Coagul Fibrinolysis
; 15(8): 663-72, 2004 Oct.
Article
en En
| MEDLINE
| ID: mdl-15613921
Histidine-proline-rich glycoprotein (HPRG) has long been known to associate with plasminogen (Plg) in solution, but the consequences of this interaction have not been defined. Here we show that HPRG adsorbed to a glycosaminoglycan (GAG) surface also binds Plg with a Kd value of 0.7 micromol/l. Moreover, we present evidence that HPRG acts as a modulator of the activation of Plg by tissue-type Plg activator. Specifically, Plg complexed with HPRG on a GAG surface is more readily activated by tissue-type Plg activator than free Plg, with a 10-fold difference in apparent catalytic efficiency (kcat/Km). HPRG also augments the increase in Plg activation caused by fibrinogen fragments either in solution or on GAG surfaces. In contrast, HPRG abrogates the stimulatory effects of fibrinogen on Plg activation in solution. These observations demonstrate that HPRG can act as either a positive or negative effector of Plg activation in vitro and may serve as a modulator of fibrinolysis in vivo.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasminógeno
/
Glicoproteínas
Límite:
Humans
Idioma:
En
Revista:
Blood Coagul Fibrinolysis
Asunto de la revista:
ANGIOLOGIA
/
HEMATOLOGIA
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido