The ADAMTS (a disintegrin-like and metalloproteinase with thrombospondin motifs) is a family of extracellular metalloproteinases mediating diverse functions including matrix degradation, blood coagulation and angiogenesis. The ADAMTS family constitutes a group of proteins composed of 19 enzymes and 7 ADAMTS-like proteins. ADAMTS4 is a well-known proteoglycanase and has angiomodulatory properties. The 837 amino acid long human ADAMTS4 protein contains a long signal peptide, a prodomain, a metalloproteinase catalytic domain with zinc-binding motif, a disintegrin-like domain, a central TSR motif, followed by a cysteine-rich region with ten conserved cysteine residues, and a spacer domain. The full-length proform human ADAMTS4 (zymogen form) has been described to be 90 kDa. In extracellular matrix (ECM), ADAMTS4 undergoes further C-terminal cleavage at Lys694-Phe695 and Thr581-Phe582, respectively, to generate two other truncated forms-53 and 40 kDa (PMID:12202483).