FRAGMENTATION OF HUMAN POLYMORPHONUCLEAR-LEUKOCYTE COLLAGENASE

Human polymorphonuclear-leucocyte collagenase (M(r) 64000) shows autop roteolytic degradation to two major fragments of M(r) 40000 and M(r) 2 7000. N-terminal sequence data and investigation of the substrate spec ificity of the fragments demonstrate that the M(r)-40 000 fragment cor responds to the catalytic domain, whereas the M(r)-27000 fragment show s no enzymic activity. The activity profile of the M(r)-40000 fragment is comparable with the specificity of the intact active collagenase ( M(r) 64000), but the ability to cleave collagen was lost. The enzymic activity of this fragment can be inhibited by either tissue inhibitor of metallo-proteinase (TIMP)-1 or recombinant TIMP-2 in a 1:1 molar ra tio. The C-terminal part of the enzyme (M(r) 27000), important for the binding reaction with collagen substrates, is involved in collagenoly sis.