A disintegrin and metalloproteinase with thrombospondin motifs 5 also known as ADAMTS5 is an enzyme that in humans is encoded by the ADAMTS5 gene. ADAMTS5 is a member of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) protein family. Members of the family share several distinct protein modules, including a propeptide region, a metalloproteinase domain, a disintegrin-like domain, and a thrombospondin type 1 (TS) motif. Individual members of this family differ in the number of C-terminal TS motifs, and some have unique C-terminal domains. The enzyme encoded by this gene contains two C-terminal TS motifs and functions as aggrecanase to cleave aggrecan, a major proteoglycan of cartilage. ADAMTS5 may also have a role in the pathogenesis of human osteoarthritis.