sh-Oligopeptide-128 SP is a single chain human peptide produced synthetically to be identical to a portion of the protein, Osteopontin, and contains 15 amino acids consisting of arginine, aspartic acid, glycine, isoleucine, leucine, serine, threonine, tyrosine and valine. Osteopontin contains a maximum of 314 amino acids which may contain disulfide bonds and/or glycosylation. It consists of the proper sequence of the 20 standard amino acids.