DISINTEGRINS - THE NATURALLY-OCCURRING ANTAGONISTS OF PLATELET FIBRINOGEN RECEPTOR

Disintegrins represent a family of low molecular weight, cysteine-rich , RGD-containing peptides which inhibit fibrinogen binding to platelet membrane glycoprotein IIb/IIIa complex as well as other ligands to RG D-dependent integrins on the surface of other cells. Disintegrins occu r in the venom of various vipers, and disintegrin-domains have been id entified in viper venom hemorrhagins. Amino acid sequences of disinteg rins are shown in comparing with those of RGD-containing non-disintegr ins. The primary structure of disintegrins differs significantly from other fibrinogen receptor antagonists occurring in the venoms of Elapi dae and leeches. Several aspects of structure-activity relationship of disintegrins, their biological activities and possible clinical appli cations are discussed..