Proteolytic activities of human ADAMTS-5: comparative studies with ADAMTS-4

J Biol Chem. 2007 Jun 22;282(25):18294-306. doi: 10.1074/jbc.M701523200. Epub 2007 Apr 12.

Abstract

Aggrecanases have been characterized as proteinases that cleave the Glu373-Ala374 bond of the aggrecan core protein, and they are multidomain metalloproteinases belonging to the ADAMTS (adamalysin with thrombospondin type 1 motifs) family. The first aggrecanases discovered were ADAMTS-4 (aggrecanase 1) and ADAMTS-5 (aggrecanase 2). They contain a zinc catalytic domain followed by non-catalytic ancillary domains, including a disintegrin domain, a thrombospondin domain, a cysteine-rich domain, and a spacer domain. In the case of ADAMTS-5, a second thrombospondin domain follows the spacer domain. We previously reported that the non-catalytic domains of ADAMTS-4 influence both its extracellular matrix interaction and proteolytic abilities. Here we report the effects of these domains of ADAMTS-5 on the extracellular matrix interaction and proteolytic activities and compare them with those of ADAMTS-4. Although the spacer domain was critical for ADAMTS-4 localization in the matrix, the cysteine-rich domain influenced ADAMTS-5 localization. Similar to previous reports of other ADAMTS family members, very little proteolytic activity was detected with the ADAMTS-5 catalytic domain alone. The sequential inclusion of each carboxyl-terminal domain enhanced its activity against aggrecan, carboxymethylated transferrin, fibromodulin, decorin, biglycan, and fibronectin. Both ADAMTS-4 and -5 had a broad optimal activity at pH 7.0-9.5. Aggrecanolytic activities were sensitive to the NaCl concentration, but activities on non-aggrecan substrates, e.g. carboxymethylated transferrin, were not affected. Although ADAMTS-4 and ADAMTS-5 had similar general proteolytic activities, the aggrecanase activity of ADAMTS-5 was at least 1,000-fold greater than that of ADAMTS-4 under physiological conditions. Our studies suggest that ADAMTS-5 is a major aggrecanase in cartilage metabolism and pathology.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM Proteins / chemistry
  • ADAM Proteins / physiology*
  • ADAMTS4 Protein
  • ADAMTS5 Protein
  • Alanine / chemistry
  • Binding Sites
  • Catalytic Domain
  • Cell Line
  • Cell Membrane / metabolism
  • Gene Deletion
  • Glutamic Acid / chemistry
  • Humans
  • Hydrogen-Ion Concentration
  • Mutation
  • Procollagen N-Endopeptidase / chemistry
  • Procollagen N-Endopeptidase / physiology*
  • Protein Binding
  • Protein Structure, Tertiary
  • Transfection

Substances

  • Glutamic Acid
  • ADAM Proteins
  • ADAMTS5 Protein
  • ADAMTS5 protein, human
  • Procollagen N-Endopeptidase
  • ADAMTS4 Protein
  • ADAMTS4 protein, human
  • Alanine