title: Rat and mouse membrane aminopeptidase P: structure analysis and tissue distribution.
abstract: Membrane-bound aminopeptidase P (mAPP) is a highly specific exopeptidase that removes the N-terminal amino acid only from a peptide (three amino acids or longer) that has a prolyl residue in the second position. mAPP can inactivate bradykinin, a potent vasodilating and cardioprotective peptide hormone, by hydrolyzing the Arg(1)-Pro(2) bond. Studies on the rat have shown that the metabolism of bradykinin is an important physiological role of this enzyme. We report here the complete coding sequences for rat and mouse mAPP determined from mRNA isolated from lung tissue. Key structural features that determine post-translational processing and substrate recognition and catalysis were identified based on sequence homologies and the crystal structure of Escherichia coli aminopeptidase P complexed with Pro-Leu. The tissue-specific expression of mAPP was studied using the polymerase chain reaction. The mAPP gene is widely, but variably, expressed in adult tissues of the rat and mouse and in mouse embryos.
authors.affiliation: Department of Pathology, Loyola University Chicago Stritch School of Medicine, 2160 S. First Ave., Maywood, IL 60153, USA.
authors.forename: Cağatay
authors.initials: C
authors.lastname: Erşahin
authors.forename: Anna M
authors.initials: AM
authors.lastname: Szpaderska
authors.forename: William H
authors.initials: WH
authors.lastname: Simmons
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015971:Gene Expression Regulation, Enzymologic; D008168:Lung / Q000737:chemistry / Q000201:enzymology*; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014018:Tissue Distribution
chemical_list: D008565:Membrane Proteins; D000626:Aminopeptidases; C022750:X-Pro aminopeptidase