title: Structural and immunological evidence for the identity of prolyl aminopeptidase with leucyl aminopeptidase.
abstract: Prolyl aminopeptidase (EC 3.4.11.5) has been assumed to be a unique enzyme catalyzing specifically the removal of unsubstituted NH2-terminal L-prolyl residues from various peptides and to be distinct from leucyl aminopeptidase (EC 3.4.11.1). In the present study, prolyl aminopeptidases were purified to apparent homogeneity from pig small intestine mucosa and human liver and their NH2-terminal amino acid sequences were determined together with that of pig kidney leucyl aminopeptidase. The NH2-terminal 24-residue sequence of pig intestinal prolyl aminopeptidase was shown to be identical with that of pig kidney leucyl aminopeptidase. The NH2-terminal sequence of human liver prolyl aminopeptidase was also shown to be very similar to that of pig kidney leucyl aminopeptidase. Further, pig intestinal prolyl aminopeptidase and pig kidney leucyl aminopeptidase were immunologically indistinguishable. These lines of evidence strongly suggest that prolyl aminopeptidase is identical with leucyl aminopeptidase.
authors.affiliation: Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsushima
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Ichinose
authors.forename: K
authors.initials: K
authors.lastname: Miki
authors.forename: K
authors.initials: K
authors.lastname: Kurokawa
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D007413:Intestinal Mucosa / Q000201:enzymology*; D007421:Intestine, Small / Q000201:enzymology; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D013552:Swine
chemical_list: D007106:Immune Sera; D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase; C022450:prolyl aminopeptidase