Contribution of molecular modeling and site-directed mutagenesis to the identification of two structural residues, Arg-220 and Asp-227, in aminopeptidase A.
Aminopeptidase A is a zinc metalloenzyme involved in the formation of brain angiotensin III, which exerts a tonic stimulatory action on the central control of blood pressure. Thus, central inhibitors of aminopeptidase A constitute putative central antihypertensive agents. Mutagenic studies have been performed to investigate organization of the aminopeptidase A active site, with a view to designing such inhibitors. The structure of one monozinc aminopeptidase (leukotriene A(4) hydrolase) was recently resolved and used to construct a three-dimensional model of the aminopeptidase A ectodomain. This new model, highly consistent with the results of mutagenic studies, showed a critical structural interaction between two conserved residues, Arg-220 and Asp-227. Mutagenic replacement of either of these two residues disrupted maturation and subcellular localization and abolished the enzymatic activity of aminopeptidase A, confirming the critical structural role of these residues. In this study, we generated the first three-dimensional model of a strict aminopeptidase, aminopeptidase A. This model constitutes a new tool to probe further the active site of aminopeptidase A and to design new inhibitors of this enzyme.
Rozenfeld
Raphael
R
INSERM, Unité 36, Collège de France, 11, place Marcelin Berthelot, 75005 Paris, France.
Iturrioz
Xavier
X
Maigret
Bernard
B
Llorens-Cortes
Catherine
C
D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry* / Q000235:genetics; D000818:Animals; D001120:Arginine / Q000737:chemistry*; D001224:Aspartic Acid / Q000737:chemistry*; D001665:Binding Sites; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D004851:Epoxide Hydrolases / Q000737:chemistry; D043384:Glutamyl Aminopeptidase; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
D011994:Recombinant Proteins; D001224:Aspartic Acid; D004247:DNA; D001120:Arginine; D004851:Epoxide Hydrolases; D000626:Aminopeptidases; D043384:Glutamyl Aminopeptidase; C043134:leukotriene A4 hydrolase