Über die chemie des haptoglobin-polymorphismus

Abstract The haptoglobin polymorphism observed in starch-gel electrophoresis is not based on a different carbohydrate and notably neuraminic acid content of the individual haptoglobin components. The differences in molecular size do not satisfactorily account for the polymorphism either, the latter being maintained after dissociation of the haptoglobin with urea into fragments of practically the same particle size. The formation of variants is based rather, as we were able to demonstrate, on differences in the amino acid composition. These concern the amino acids glycine, leucine, tyrosinc and phenylalanine. The fact that gene-dependent variants possess a different primary structure was also demonstrated in the case of haemoglobins, human albumins and β-lactoglobins.