Post-proline cleaving enzyme. Synthesis of a new fluorogenic substrate and distribution of the endopeptidase in rat tissues and body fluids of man.
Synthesis and application of the first fluorogenic substrate, N-carbobenzoxyglycylprolyl-4-methylcoumarinyl amide (Z-Gly-Pro-MeCouNH) for the determination of the post-proline cleaving enzyme (EC 3.4.21.-) were reported. Maximal activity of the enzyme purified from lamb kidney for the new substrate was observed at pH 7.0. This substrate showed a higher affinity (Km = 0.02 mM) for the enzyme than the proline containing substrates studied previously and allowed the detection of 10-50 ng post-proline cleaving enzyme activity per ml sample after a 1 min incubation period. Distribution of post-proline cleaving enzyme and other proline specific peptidases in rat tissues was studied using Z-Gly-Pro-MeCouNH and other proline-containing substrates. High post-proline cleaving enzyme activity was observed in testis, liver and skeletal muscle. Inhibition experiments indicated that post-proline cleaving enzyme activity was completely inactivated by 0.1 mM diisopropylphosphofluoridate and Z-Gly-Pro-chloromethylketone, as had been found in the case of the enzyme isolated from lamb kidney. Activity in human body fluids was also tested for levels of post-proline cleaving enzyme activity using Z-Gly-Pro-MeCouNH and semen was found to show the highest cleaving activity.
D000619:Aminohydrolases / Q000378:metabolism; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003374:Coumarins / Q000138:chemical synthesis; D010450:Endopeptidases / Q000378:metabolism*; D004950:Esterases / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000201:enzymology; D008297:Male; D009842:Oligopeptides / Q000138:chemical synthesis; D000085822:Prolyl Oligopeptidases; D051381:Rats; D012697:Serine Endopeptidases; D012756:Sheep; D013050:Spectrometry, Fluorescence; D014018:Tissue Distribution
D003374:Coumarins; D009842:Oligopeptides; C020988:N-carbobenzoxyglycyl-prolyl-4-methylcoumarinyl amide; D004950:Esterases; D010450:Endopeptidases; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases; D000619:Aminohydrolases