Isolation and purification of Rh(E) antigen

The Rh(E) antigen of human red blood cell membranes has been isolated. The method of preparation was as follows: Red cell membranes were solubilized using ethylenediaminetetraacetic acid followed by NaCl. Membrane ultrafilters were used to separtely 75% of the arginine from the polypeptide by chemical treatment of the polypeptide suing methods designed to cleave carboxyl-terminal amino acids. The highly branched structure of the cyanophycin granule polypeptide is similar in form to synthetically produced multichain polyamino acids, and using the nomenclature for describing multichain polyamino acids, it is proposed that the cyanophycin granule polypeptide be called multi-l-arginyl- -polyaspartic acid.