Cleavage of type VII collagen by interstitial collagenase and type IV collagenase (gelatinase) derived from human skin.

摘要: Type VII collagen is the major structural protein of anchoring fibrils, which are believed to be critical for epidermal-dermal adhesion in basement membrane zone skin. To elucidate possible mechanisms turnover this protein, we examined capacities two proteases, human skin collagenase, degrades interstitial collagens, and a protease with gelatinolytic type IV collagenase activities, cleave collagen. At temperatures below denaturation temperature, pepsin cleaves into products approximately 95 75 kDa. Human cleaved stable fragments 83 80 kDa, (gelatinase) produced broad band kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cleavage was linear time enzyme concentration both enzymes. Although Km values were similar enzymes, catalytic rate cleavage much faster than shows greater increase increasing temperature. Sequence analysis from enzymes showed typical collagenous sequences, indicating relaxation helical part molecule at physiological temperature makes it susceptible degradation. Interstitial normal cells patients recessive dystrophic epidermolysis bullosa, severe hereditary blistering disease an fibril defect excessive production can observed, identical These data suggest pathophysiological link between increased levels observed decrease or absence fibrils.