Development of a peptide antibody specific to human glutathione S-transferase alpha 4-4 (hGSTA4-4) reveals preferential localization in human liver mitochondria.
The reactive cellular products generated during the peroxidation of membrane lipids have been implicated as causative agents in a variety of degenerative diseases and aging. In particular, 4-hydroxynon-2-enal (4HNE) is among the most of the produced during lipid peroxidation. In humans and rodent species, the alpha 4 subclass of glutathione S-transferases (mGSTA4-4, rGSTA4-4, hGST-5.8, and hGSTA4-4) exhibits uniquely high glutathione conjugation activity toward 4HNE and other hydroxyalkenals. In human liver, hGSTA4-4-mediated 4HNE conjugation appears to represent the high-affinity pathway for 4HNE detoxification. In the present study, a highly specific polyclonal antibody was developed against hGSTA4-4. Western blotting analysis of human liver subcellular fractions as well as N-terminal sequencing revealed that hGSTA4-4 was localized to mitochondrial fractions, but was not detected in cytosolic fractions. Our results provide evidence that in adult liver, hGSTA4-4 is specifically targeted to the mitochondrion to the apparent exclusion of the cytosol. Targeting of hGSTA4-4 to the mitochondrion holds implications for degenerative diseases associated with oxidative stress that arise from aerobic respiration.
Gardner
J L
JL
Department of Physiological Sciences, University of Florida, Gainesville, Florida 32611, USA.
Gallagher
E P
EP
D000328:Adult; D000447:Aldehydes / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D002645:Chickens; D005982:Glutathione Transferase / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D008658:Inactivation, Metabolic; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000201:enzymology
D000447:Aldehydes; D007527:Isoenzymes; D005982:Glutathione Transferase; C119995:glutathione S-transferase alpha; C027576:4-hydroxy-2-nonenal