Protein C.
Review published in Progress in hemostasis and thrombosis (1984)
Abstract
The protein C anticoagulant pathway provides many new insights into control mechanisms for regulating coagulation. The observation that protein C deficiency is associated with thrombotic tendencies in the heterozygote (106-109) and early, lethal thrombosis in the homozygote (110, 111) points to the importance of the system as a major regulatory pathway. The complexity of the system has only recently begun to emerge. Thrombin activation of protein C at the endothelial cell surface requires not only the synthesis of thrombomodulin but the coupling of the receptor to a protein C binding site. It is reasonable to assume that an inherited or acquired deficiency in thrombomodulin might lead to thrombotic tendencies. This aspect of the system may explain, in part, the association between vascular disease and thrombosis. Once activated, protein C has an almost total dependence on protein S to express anticoagulant activity. (98) This suggests that deficiencies of protein S may also be associated with thrombotic tendencies. Protein S offers an additional intriguing property. Protein S, a regulatory protein of the coagulation system, is found both free and associated with C4BP, a regulatory protein of the complement system. The high affinity, very stable interaction between these components (85) suggests that the interaction is likely to be involved in regulation. (89) The importance of the interaction remains to be demonstrated, but clearly this is a potential direct link between major control proteins of the coagulation and complement system. Clinical studies suggest that protein C and/or thrombomodulin might be effective therapeutically. Certainly, protein C supplementation during the onset of oral anticoagulant therapy would be expected to circumvent the transient rapid decrease in protein C levels that may influence the early effectiveness of oral anticoagulants. (119) In addition to the systems clinical importance, protein C, its activation, and its function offer a variety of intriguing biochemical problems. For instance, how does thrombomodulin alter the specificity of thrombin? What is the protein C binding site on the cell surface, and what role does Factor Va or its degradation products play in the formation and regulation of this site? How does protein S facilitate activated protein C anticoagulant activity and what roles do membrane surfaces play in this system? What role does beta-hydroxyaspartic acid play in protein C activation and function? How does activated protein C influence fibrinolytic activity? The answers to these questions will undoubtedly add to our understanding of the fundamental mechanisms involved in regulating blood coagulation.(ABSTRACT TRUNCATED AT 400 WORDS)
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
The protein C anticoagulant pathway provides many new insights into control mechanisms for regulating coagulation. The observation that protein C deficiency is associated with thrombotic tendencies in the heterozygote (106-109) and early, lethal thrombosis in the homozygote (110, 111) points to the...
Por qué esto importa para la hirudoterapia
Esta revisión examina la vía anticoagulante de la proteína C, describiendo la activación trombina-trombomodulina en la superficie endotelial, la dependencia de la proteína C activada respecto a la proteína S, y las asociaciones de la deficiencia de proteína C, proteína S o trombomodulina con tendencias trombóticas. También señala posibles consideraciones terapéuticas, como la suplementación con proteína C durante el inicio del tratamiento anticoagulante oral y un posible vínculo entre la coagulación y la regulación del complemento a través de la interacción proteína S-C4BP. El resumen aborda la regulación endógena de la coagulación y es ampliamente relevante para la biología de la hemostasia/trombosis. No menciona sanguijuelas, hirudina, anticoagulantes derivados de sanguijuelas ni hirudoterapia, por lo que no aporta evidencia directa para la terapia con sanguijuelas ni para el secretoma de la sanguijuela.
Citación
Protein C.
Esmon · Progress in hemostasis and thrombosis, 1984
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: 18 de junio de 2026