Process for preparation of mixtures of polypeptides using purified hydrobromic acid

摘要

The Subject invention provides an improved process for obtaining a mixture of polypeptides having nonuniform amino acid sequences, where each polypeptide consists essentially of alanine, glutamic acid, tyrosine and lysine where the resulting mixture of polypeptides comprises less than 0.3% brominated tyrosine and less than 1000 ppm metal ion impurities.