ADAMTS4, Recombinant, His-Tag (Aggrecanase I, A Disintegrin And Metalloproteinase with ThromboSpondin-3 motif)

ADAMTS (a disintegrin and metalloproteinase with thrombospondin motif) is a novel family of extrcellular proteinases (1). Presently nine family members have been identified in mammals (1). ADAMTS4 was first purified from I1-1 (stimulated bovine nasal cartilage conditioned media) and human ADAMTS4 (cDNA was cloned from a human heart cDNA library) (2). Mature ADAMTS4 consists of a prodomain which confers latency to the proenzyme, a catalytic domain, a disintegrin domain and a C-terminal sequence with a thrombospondin type-1 motif. The prodomain is most likely cleaved off by a furin-type enzyme before active ADAMTS4 is released from cells. Active ADAMTS4 consists of 625 amino acids (F213-K837) with a calculated Mr of 67 943 (2).ADAMTS4 hydrolyzes aggrecan, the major proteoglycan of articular cartilage (2). As aggrecan is also digested by 2 other members of the ADAMTS family, ADAMTS1(3) and ADAMTS5 (4), aggrecan degradation products found in normal and rheumatoid and osteoarthritic joint cartilage (5) may arise from action of either of the 3 proteinases. Isolated ADAMTS4 hydrolyzes aggrecan at 5 different sites (6). Four cleavage sites are located in the chondroitin sulfate-rich region between globular domains G2 and G3, while one site is placed in the rod-shaped polypeptide between globular domains G1 and G2. The thrombospondin motif in ADAMTS4 appears to be critical for aggrecan substrate recognition and cleavage (7). ADAMTS4 hydrolyzes also other lecticans as brevican (8) and versican (9). Applications: Recombinant ADAMTS4 is used to study the degradation of extracellular matrix proteoglycans, to screen for inhibitors of proteoglycan hydrolysis and to characterize inhibitor actions. The enzyme can also serve as standard in enzymatic and immunochemical assays. Activity: Aggrecanase activity of ADAMTS4 is determined with recombinant His-tagged aggrecan interglobular domain. ADAMTS4 hydrolyzes the