| Abstract: | ![]()
From the culture medium of the Bacillus subtilis strain ATCC 6633 the proteolytic enzyme activity was isolated by ammonium sulphate precipitation and acetone treatment. In the case of the isolated activity it is a question of a serine protease with a pH optimum of 10, which is inhibited by diisopropyl fluoro-phosphate and sodium ethylene diamine tetra-acetic acid and is not influenced by o-phenanthroline. With the enzyme preparations thus obtained, decalcified sections of caries-free human teeth were incubated at pH 7.0 and 37 °C both with and without di-isopropyl fluoro-phosphate. Under the influence of the enzyme action there were changes in the matachromatic structures and finally the disintegration of the decalcified dental tissue. Propitious points of attack are the cement-dentine boundary and the central sections of the globuli. The isolated enzyme thus leads to the same decomposition phenomena as the direct incubation with Bacillus subtilis. With this enzymatic decomposition of the dental tissue, determinable quantities of nitrogen are released biochemically in the incubation solution. It is assumed that the hydrolysed substance is a glycoproteid with a non-collagenic protein component. |
