s-Mussel Oligopeptide-2 is a single chain protein containing 18 amino acids. It is synthetically produced based on a sequence from Adhesive Plaque Matrix Protein which is found in the mussel, Mytilus galloprovincialis. Adhesive Plaque Matrix Protein contains 875 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 amino acids.