Vitronectin

Multifunctional glycoprotein synthesized in the liver with a molecular mass of 78 000 Daltons, which is detectable in the blood and in the extracellular matrix (Schvartz I 1999). Vitronectin belongs to the pexin family; it is structurally a labile molecule that organises itself into a multimeric form through interactions with numerous structures.

Thus, the molecule binds to glycosaminoglycans, collagen, plasminogen and to the urokinase receptor. Vitronectin also binds to complement fractions, to heparin and to thrombin/antithrombin III complexes. Vitronectin supports cell adhesion functions in the coagulation and immune system, inhibits the membrane-damaging effect of the cytolytic cascade of the complement system and binds to various serpins (Preissner KT et al. 2011).

Decreased plasma concentrations of vitronectin are found in disseminated intravascular coagulation, also in degenerative liver damage. Vitronectin deposits are found in atherosclerotic plaques.

1. Jenne D et al (1987) Nucleotide sequence and organization of the human S-protein gene: repeating peptide motifs in the "pexin" family and a model for their evolution. Biochemistry 26: 6735-6742.
2. Preissner KT et al (1986) Role of vitronectin and its receptors in haemostasis and vascular remodeling. Thromb Res 89: 1-21.
3. Preissner KT et al (2011) Vitronectin in vascular context: facets of a multitalented matricellular protein.1 Semin Thromb Hemost 37:408-24.
4. Schvartz I (1999) Vitronectin. Int J Biochem Cell Biol 31:539-544.