[Inventory of proteolytic activity of a new collagenolytic bacteria Empedobacter collagenolyticum]

During the growth of Empedobacter collagenolyticum on a medium with gelatin, only one proteinase, a collagenase, was excreted in the culture medium. No other proteolytic activity was detected in the extracellular medium or in acellular extracts. The other proteases of this bacteria are principally intracellular peptidases. By electrophoresis of an acellular extract five peptidases were separated; they were aminopeptidases and dipeptidases. Some of them exhibited a specificity towards peptides with aminoacid frequently found in collagen; Gly-Leu, Gly-Pro, Pro-Gly-Gly. Two other peptidases seem to have special specificity, one of them hydrolyses peptides with lysine residues at the NH2 terminal end, the other one hydrolyses dipeptides of the structure Lys-X. These enzymes were also found in the culture medium; they certainly play an important role in bacterial nutrition.