A new enzyme, proline acylase (N-acyl-l-proline amidohydrolase) from Pseudomonas species

Abstract A new enzyme, proline acylase, extracted from a strain of Pseudomonas species has been purified to apparent homogeneity and has been shown to hydrolyze specifically N- acyl - l - proline derivatives such as N- acetyl - l - proline and chloroacetyl- l -proline. N -Acetylamino acids other than l -proline were unsusceptible, or nearly so. The enzyme also hydrolyzed the carboxyterminal proline residue in a peptide when its penultimate position was occupied by a glycine, such as Z-Gly- l Pro and Z-Gly- l Pro- l Leu-Gly- l Pro. It has a pH optimum at pH 6.0 and was inhibited by chelating reagent. The molecular weight was estimated to be 597 000 and 623 000 by sedimentation equilibrium and gel filtration, respectively. Upon disc electrophoresis in 1% SDS, the purified preparation migrates as a single band of molecular weight 55 000. The sedimentation coefficient and isoelectric point, determined by polyacrylamide gel electrophoresis, were s 20, w 0 = 18 S and pH = 5.0, respectively.