sr-(Polypeptide-166 Oligopeptide-178) is a single chain recombinant peptide, produced by fermentation in Pichia pastoris. The starting gene is synthesized by the fusion of the gene from Polypeptide-166 and Oligopeptide-178. The fusion peptide contains 971 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.