title: Establishment of the enzymatic protein acetylation independent of acetyl CoA: recombinant glutathione S-transferase 3-3 is acetylated by a novel membrane-bound transacetylase using 7,8-diacetoxy-4-methyl coumarin as the acetyl donor.
abstract: The current knowledge on biological protein acetylation is confined to acetyl CoA-dependent acetylation of protein catalyzed by specific acetyl transferases and the non-enzymatic acetylation of protein by acetylated xenobiotics such as aspirin. We have discovered a membrane-bound enzyme catalyzing the transfer of acetyl groups from the acetyl donor 7,8-diacetoxy-4-methyl coumarin (DAMC) to glutathione S-transferase 3-3 (GST3-3), termed DAMC:protein transacetylase (TAase). The purified enzyme was incubated with recombinant GST3-3 subunit and DAMC, the modified protein was isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in gel digested with trypsin and the tryptic digest was analyzed by mass spectrometry. The N-terminus and six lysines, Lys-51, -82, -124, -181, -191 and -210, were found to be acetylated. The acetylation of GST3-3 described above was not observed in the absence of either DAMC or TAase. These results clearly establish the phenomenon of protein acetylation independent of acetyl CoA catalyzed by a hitherto unknown enzyme (TAase) utilizing a certain xenobiotic acetate (DAMC) as the active acetyl donor.
authors.affiliation: Department of Biochemistry, V.P. Chest Institute, University of Delhi, India.
authors.forename: Ekta
authors.initials: E
authors.lastname: Kohli
authors.forename: Marco
authors.initials: M
authors.lastname: Gaspari
authors.forename: Hanumantharao G
authors.initials: HG
authors.lastname: Raj
authors.forename: Virinder S
authors.initials: VS
authors.lastname: Parmar
authors.forename: Jan
authors.initials: J
authors.lastname: van der Greef
authors.forename: Garima
authors.initials: G
authors.lastname: Gupta
authors.forename: Ranju
authors.initials: R
authors.lastname: Kumari
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Prasad
authors.forename: Sanjay
authors.initials: S
authors.lastname: Goel
authors.forename: Giridhari
authors.initials: G
authors.lastname: Pal
authors.forename: Yogesh K
authors.initials: YK
authors.lastname: Tyagi
authors.forename: Subhash C
authors.initials: SC
authors.lastname: Jain
authors.forename: Nizamuddin
authors.initials: N
authors.lastname: Ahmad
authors.forename: Arthur C
authors.initials: AC
authors.lastname: Watterson
authors.forename: Carl E
authors.initials: CE
authors.lastname: Olsen
mesh_terms: D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000107:Acetylation; D000115:Acetylesterase / Q000378:metabolism*; D003374:Coumarins / Q000737:chemistry*; D005982:Glutathione Transferase / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: C114369:7,8-diacetoxy-4-methylcoumarin; D003374:Coumarins; D011994:Recombinant Proteins; D000105:Acetyl Coenzyme A; D005982:Glutathione Transferase; D000115:Acetylesterase