Aggrecanases ADAMTS1, ADAMTS4 and ADAMTS5 are members of the ADAMTS-family of proteases (ADAMTS = A disintegrin and metalloprotease with thrombospondin motif). They aresynthesized as multidomain proteins consisting of prodomains, protease, disintegrin, thrombospondin and cys-rich domains followed by spacer regions and additional thrombospondin motifs. The prodomains are cleaved-off intracellularly and the enzymes are processed further from their C-terminal ends after secretion.

Aggrecanases cleave specific peptide bonds in aggrecan, the main proteoglycan of articular cartilage. They hydrolyze also other lecticanes as versican and brevican. Convincing evidence indicates that aggrecanases are mainly responsible for excessive aggrecan degradation in osteoarthritic joints.