I--isolation and electron microscope studies of a potent platelet-aggregating glycoprotein from the venom of Crotalus durissus cascavella.

A potent acid-soluble platelet-aggregating glycoprotein was purified from the venom of Crotalus durissus cascavella by molecular sieve chromatography on Sephadex G-75 and by adsorption onto Sepharose 4B gels at acidic pH. This new protein with an apparent Mr of 300,000 at acidic pH and containing a low amount of sugars is non-toxic for mice. Electron microscope studies showed that the platelet-aggregating glycoprotein appeared as regular rosettes of 150 A in diameter at acidic pH and underwent polymerization in rod-like particles in the presence of sodium chloride. This glycoprotein, probably hydrophobic, is dissociated into an active molecular form whose apparent Mr was 144,000; however, it is believed to still be a not totally dissociated molecule.