sr-(Oligopeptide-150 Silkworm Polypeptide-2 Dipeptide-19 Hexapeptide-40) is a single chain recombinant peptide produced by fermentation in E. coli. The starting gene is synthesized by the fusion of the gene from Oligopeptide-150, sr-Silkworm Polypeptide-2, Dipeptide-19, and Hexapeptide-40. The fusion peptide contains 757 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 amino acids.