[Post-proline hydrolysis activities in cerebrospinal fluid]

Post-proline hydrolytic-activity exists in various tissues and body fluids of human organism. Using electrophoretic techniques, column chromatographic methods and kinetic investigations two peaks of proteolytic activity towards glycyl-prolyl-p-nitroanilide were detected in human cerebrospinal fluid. The identity of one enzyme with dipeptidylpeptidase IV (EC 3.4.14.5) must now constitute proof of this. Among 650 patients with cerebral diseases, characterised by post-proline hydrolytic activity in cerebrospinal fluid, high enzyme activity coincide with bacterial meningitis. Furthermore, all bacteria which could be isolated from cerebrospinal fluid exhibit high activities of post-proline cleaving hydrolases. Until now, the origin of the cerebrospinal post proline hydrolytic activity is not clear, although our investigations suggested, that lymphocytes, cerebral parenchyma and bacteria may be involved in the enzyme secretion.