Purification and characterization of a glutathione S-transferase Omega in pig: evidence for two distinct organ-specific transcripts.
A cytosolic glutathione S-transferase (GST, EC 2.5.1.18) from the recently characterized Omega class [GSTO; Board et al. 2000, J. Biol. Chem. 275, 24798-24806] has been identified in pig organs. It was found widely distributed in the different tissues investigated and especially abundant in liver and muscle. The hepatic enzyme has been purified to homogeneity by using its selective affinity for S-hexylglutathione over GSH, thus providing a simple method to isolate mammalian GSTO. The dimeric protein has a subunit molecular mass of 27328 Da as measured by electrospray ionization MS. Internal peptide sequencing and complete cDNA sequencing revealed strong similarities with its human recombinant orthologue and two rodent GST-like proteins with the ability to catalyse the GSH-dependent reduction of dehydroascorbate. Additional similarities, including the presence of a specific N-terminal extension and of immunological cross-reactivity, support the results. Moreover, this gene encoding GSTO generates two organ-specific transcripts, suggesting transcriptional mechanisms with a significance that is as yet uncharacterized.
Rouimi
P
P
Institut National de la Recherche Agronomique (INRA), UMR Xénobiotiques, 180 chemin de Tournefeuille, BP3, F-31931 Toulouse Cedex, France. prouimi@toulouse.inra.fr
Anglade
P
P
Benzekri
A
A
Costet
P
P
Debrauwer
L
L
Pineau
T
T
Tulliez
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D018076:DNA, Complementary / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives / Q000737:chemistry; D005982:Glutathione Transferase / Q000737:chemistry*; D006801:Humans; D015151:Immunoblotting; D008099:Liver / Q000201:enzymology*; D051379:Mice; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D021241:Spectrometry, Mass, Electrospray Ionization; D013347:Subcellular Fractions; D013552:Swine; D013997:Time Factors; D014018:Tissue Distribution
D018076:DNA, Complementary; D010455:Peptides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D005982:Glutathione Transferase; D005978:Glutathione; C033550:hexylglutathione