sh-Polypeptide-50 sh-Polypeptide-56 is a single chain recombinant fusion peptide, produced by fermentation in E. coli. The starting gene is synthesized by the fusion of the gene from sh-Polypeptide-50 and sh-Polypeptdie-56. The fused peptide contains 1790 amino acids and consists of the proper sequence of the 20 standard amino acids.