Structural and functional characteristics of vitronectin and its role in haemostasis
Vitronectin is one of the main adhesive proteins circulating in plasma and the component of extracellular matrix. This protein is also present in platelet alpha granules. Structural peculiarities of vitronectin allow it to take part in many processes under normal and pathological states of haemostasis. In plasma, vitronectin circulates as a native monomeric form, but under activation it is transformed into oligomeric form that displays affinity for heparin and forms a stable complex with plasminogen activator inhibitor PAI-1. Oligomeric vitronectin accumulates in atherosclerotic plaques and at sites of vascular injury or inflammation. Recently, new data concerning the functional role of this protein have been obtained. In the present review we have an attempt to summarize the experimental data and clearly define the role of this protein in haemostasis.