Tyrosine kinases in normal human blood cells

Abstract
The major tyrosine kinase from platelets was purified as a 51 kDa active enzyme which was shown to be a degradation product of the protooncogene product p60c-src. Immuno-depletion experiments using a monoclonal antibody recognizing p60c-src failed to remove band 3 phosphorylating activity from red blood cell membranes. The erythrocyte tyrosine kinase was not at all immunoprecipitated by this antibody under conditions where the platelet enzyme was immunoprecipitated.