Degradation of extracellular-matrix proteins by human cathepsin B from normal and tumour tissues.

摘要: Our laboratory has previously demonstrated that increased malignancy of several histological types human and animal tumours is associated with increases in their cathepsin B activity, particularly activity plasma-membrane/endosomal vesicles or shed vesicles. Here we report from normal tumour tissues degrades purified extracellular-matrix components, type IV collagen, laminin fibronectin, at both acid pH neutral pH. The number sizes degradation products were analysed by SDS/PAGE. Cathepsin sources exhibited similar activities towards, patterns cleavage of, the proteins. At pH, appeared to undergo autodegradation, a process was decreased presence alternative substrates such as readily degraded collagen 25 degrees C, indicating towards native collagen. Fibronectin 100-200 kDa 18 22 observed. A single 70 fragment released under non-reducing conditions multiple fragments ranging 45 200 reducing conditions. These results suggest near surface malignant cells may play functional role focal dissolution extracellular matrices.