title: Aspartate 496 from the subsite S2 drives specificity of human dipeptidyl peptidase III.
abstract: Human dipeptidyl peptidase III (hDPP III) is a member of the M49 metallopeptidase family, which is involved in intracellular protein catabolism and oxidative stress response. To investigate the structural basis of hDPP III preference for diarginyl arylamide, using site-directed mutagenesis, we altered its S2 subsite to mimic the counterpart in yeast enzyme. Kinetic studies revealed that the single mutant D496G lost selectivity due to the increase of the Km value. The D496G, but not S504G, showed significantly decreased binding of peptides with N-terminal arginine, and of tynorphin. The results obtained identify Asp496 as an important determinant of human DPP III substrate specificity.
authors.forename: Marija
authors.initials: M
authors.lastname: Abramić
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Karačić
authors.forename: Maja
authors.initials: M
authors.lastname: Šemanjski
authors.forename: Bojana
authors.initials: B
authors.lastname: Vukelić
authors.forename: Nina
authors.initials: N
authors.lastname: Jajčanin-Jozić
mesh_terms: D000577:Amides / Q000378:metabolism; D000595:Amino Acid Sequence; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism; D001224:Aspartic Acid / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D018360:Crystallography, X-Ray; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D017354:Point Mutation; D013379:Substrate Specificity
chemical_list: D000577:Amides; D010455:Peptides; D001224:Aspartic Acid; D001120:Arginine; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C539603:DPP3 protein, human