Comparative study of the major glycoproteins of the plasma membrane and secretory granule membranes of porcine platelets.
The major glycoproteins of porcine platelet plasma membranes and alpha-granule membranes were compared. Significant cross-contamination of the two preparations was ruled out by surface labeling and proteolysis experiments. At least four of the major glycoproteins of the alpha-granule membrane had counterparts in the plasma membranes with identical molecular weight and lectin-binding properties. Two of these (mol. wts 110,000 and 125,000) were further analysed by one-dimensional peptide mapping. The results confirmed that there are two distinct pools of identical glycoproteins: one on the surface membrane and the other on the alpha-granular membrane. The 110,000 and 125,000 mol. wt glycoproteins are probably equivalent to glycoproteins IIb and IIIa of the human platelet and may therefore be involved in fibrinogen binding.
D000818:Animals; D001792:Blood Platelets / Q000032:analysis*; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D003594:Cytoplasmic Granules / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis*; D008970:Molecular Weight; D013552:Swine
D006023:Glycoproteins; D008565:Membrane Proteins