Octapeptide-22 r-Thermus Thermophilus Putative Esterase Hexapeptide-40 is a single chain recombinant fusion peptide, produced by fermentation in E. coli. The starting gene is synthesized by the fusion of the gene that codes for Thermus Thermophilus Putative Esterase, Octapeptide-22, and Hexapeptide-40. The fused peptide contains 329 amino acids and consists of the proper sequence of the 20 standard amino acids.