A new genetic polymorphism in human platelet polypeptides detected by two-dimensional electrophoresis.

We described a new genetic polymorphism of human platelet polypeptide, detected by two-dimensional polyacrylamide gel electrophoresis followed by silver-staining. The polymorphism was tentatively designated thrombocyte B (ThB) with a molecular weight of 34 kDa and isoelectric point of 4.7-4.8. In this polypeptide, three different electrophoretic types (1-1, 1-2, 2-2) were identified. Family and population studies indicate that the three phenotypes of the polypeptide are determined by two common alleles at a single autosomal locus. In a Japanese population, the gene frequency of ThB 1/ThB 2 was 0.74/0.26. The ThB polypeptide was not found in other blood cells and decreased or disappeared during the preparation or storage of platelets.