The Degradation of Human Dentine Collagen by Enzymes Derived From Bacillus Subtilis

Insoluble collagen was prepared from human root dentine. This material was extensively digested by preparations of crystalline proteinase and crude α amylase, derived from Bacillus subtilis, both of which exhibited proteolytic activity characteristic of the alkaline bacillopeptidases. The degradation products varied in size from small dialysable peptides to large fibrillar structures, visible in the electron microscope. These latter products were themselves heterogeneous in respect to their size and structural integrity, thus differing from the preparations of “polymeric collagen” described by other authors. The total extent of solubilisation was very much greater at 37°C than at 20°C, suggesting some thermal instability of the collagen of this tissue. The susceptibility described for human dentine collagen to digestion by these non-specific proteases is notable since insoluble collagens prepared from nonmineralised tissues are generally considered to be resistant to proteolytic enzymes other than the collagenases.