Recombinant Human I-309 produced in E.Coli is a single,non-glycosylated, polypeptide chain containing 74 amino acids and having a molecular mass of 8504 Dalton. rHuI-309 is purified by proprietary chromatographic techniques.The sequence of the first five N-terminal amino acids was determined and was found to be Ser-Lys-Ser-Met-Gln.