title: S-(4-Nitrophenacyl)glutathione is a specific substrate for glutathione transferase omega 1-1.
abstract: Glutathione transferase omega 1-1 (GSTO1-1) catalyzes the biotransformation of arsenic and is implicated as a factor influencing the age-at-onset of Alzheimer's disease and the posttranslational activation of interleukin 1beta (IL-1beta). Investigation of the biological role of GSTO1-1 variants has been hampered by the lack of a specific assay for GSTO1-1 activity in tissue samples that contain other GSTs and other enzymes with similar catalytic specificities. Previous studies (P. G. Board and M. W. Anders, Chem. Res. Toxicol. 20 (2007) 149-154) have shown that GSTO1-1 catalyzes the reduction of S-(phenacyl)glutathiones to acetophenones. A new substrate, S-(4-nitrophenacyl)glutathione (4NPG), has been prepared and found to have a high turnover with GSTO1-1 but negligible activity with GSTO2-2 and other members of the glutathione transferase superfamily. A spectrophotometric assay with 4NPG as a substrate has been used to determine GSTO1-1 activity in several human breast cancer cell lines and in mouse liver and brain tissues.
authors.affiliation: Molecular Genetics Group, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia. philip.board@anu.edu.au
authors.forename: Philip G
authors.initials: PG
authors.lastname: Board
authors.forename: Marjorie
authors.initials: M
authors.lastname: Coggan
authors.forename: Jean
authors.initials: J
authors.lastname: Cappello
authors.forename: Huina
authors.initials: H
authors.lastname: Zhou
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Oakley
authors.forename: M W
authors.initials: MW
authors.lastname: Anders
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000201:enzymology; D045744:Cell Line, Tumor; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D051379:Mice; D013056:Spectrophotometry, Ultraviolet
chemical_list: C527914:S-(4-nitrophenacyl)glutathione; C490476:GSTO1 protein, human; D005982:Glutathione Transferase; D005978:Glutathione