Niyibizi C, Chan R, Wu J J, Eyre D
Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, PA 15261.
Biochem Biophys Res Commun. 1994 Jul 15;202(1):328-33. doi: 10.1006/bbrc.1994.1931.
Native type V collagen molecules resist mammalian collagenase but are cleaved by certain gelatinases. We report a prominent site of cleavage within the collagen type V molecules by 92 kDa gelatinase (MMP-9). The enzyme was purified from conditioned medium of a rabbit synovial cell line (HIG-82). It cleaved native type V collagen from bovine bone in solution at two molecular sites, one near the amino-terminus, the other producing a 3/5 C-terminal fragment. Amino-terminal sequence analysis of the individual alpha chains from this latter fragment showed that MMP-9 had cleaved between residues Gly439-Val in both alpha 1(V) and alpha (XI) and between residues Gly445-Leu in the alpha 2(V) chain. These sites are close to the previously reported trypsin-cleavage site. The findings imply that gelatinases may be necessary for initiating or completing degradation of type I/type V copolymeric fibrils for growth and remodeling of extracellular collagen.
