Isolation and characterization of the alpha and beta chains of human platelet glycoprotein Ib.

Human platelet glycoprotein Ib has been purified in milligram amounts from platelets obtained by pheresis of thrombocytotic donors. Purification steps included lectin (wheat germ agglutinin) and immuno (murine monoclonal anti-glycoprotein Ib antibody)-affinity chromatography. The disulfide-linked individual alpha and beta chains of GPIb were separated and the amino-terminal amino acid sequence of each chain was determined. Rabbit polyclonal antibody directed against each individual chain was prepared by affinity chromatography and shown to be monospecific by western blot analysis using whole platelet lysate as antigen. These studies outline a useful approach to isolate and characterize the individual chains of GPIb.