sr-Tetra (Tetra sh-Polypeptide-69 Dipeptide-78) Oligopeptide-252 is a single chain recombinant peptide, produced by fermentation in E. coli. The starting gene is synthesized by the fusion of four repeats of a tetramer of sh-Polypeptide-69 followed by Dipeptide-78, and Oligopeptide-252. The fusion peptide contains 501 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.