title: Tyrosine nitration moderates the peptidase activity of human methionyl aminopeptidase 2.
abstract: Methionyl aminopeptidase 2 (MetAP2) plays an important role in the regulation of angiogenesis. This study examined whether nitration of MetAP2 alters its enzymatic activity in vitro. The activity of unmodified, nitrated and oxidised MetAP2 was assessed and it was found that nitration significantly reduced its ability to cleave a chromogenic substrate. Mass spectrometry analysis identified Tyr336 as a nitrated residue in MetAP2. Structural and evolutionary analysis indicate that this is an important residue for MetAP2 activity. Combined, the results show that the activity of MetAP2 is reduced by nitration and raise the possibility that nitration of MetAP2 is a mechanism contributing to endothelial dysfunction.
authors.affiliation: Lowy Cancer Research Centre and the Prince of Wales Clinical School, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: John Y
authors.initials: JY
authors.lastname: Ng
authors.forename: Joyce
authors.initials: J
authors.lastname: Chiu
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Hogg
authors.forename: Jason W H
authors.initials: JW
authors.lastname: Wong
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004789:Enzyme Activation; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006418:Heme / Q000378:metabolism; D006801:Humans; D063208:Methionyl Aminopeptidases; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
chemical_list: D006023:Glycoproteins; C002744:3-nitrotyrosine; D014443:Tyrosine; D006418:Heme; D000626:Aminopeptidases; C081311:METAP2 protein, human; D063208:Methionyl Aminopeptidases
keywords: Endothelial dysfunction; Methionyl aminopeptidase 2; Nitration; Nitrotyrosine