Anionic glutathione S-transferases of human erythrocytes, placenta, and lung: evidence for structural differences.
Ahmad-H; Medh-RD; Singh-SV; Caccuri-AM; Ansari-GA; Awasthi-YC
Enzyme 1989; 42(3):129-135
A study was done to elucidate the structural interrelationships among glutathione S-transferase (GST) Pi class isozymes, those found in human placenta, lung, and erythrocytes, by comparing the high pressure liquid chromatographic profiles of peptide fragments of these isozymes generated by digestion of the purified enzymes with trypsin. The GST isozymes purified were apparently homogeneous as evidenced by SDS polyacrylamide gel electrophoresis. Antibodies raised separately against the GST Pi class of human placenta and lung were used to determine the immunological relationship of these isozymes. Both the antibodies cross reacted with anionic isozymes isolated from all three tissues. The N-terminal region amino acid sequence of erythrocyte GST was identical to the reported sequences of anionic GSTs of the lung and placenta up to 231 residues, suggesting a strong structural homology among the Pi class isozymes of different human tissues. Several peptides with identical retention time were revealed on analysis of the high performance liquid chromatography profiles. One of the most notable differences was the absence of a peptide with a retention time of 42.2 minutes in the profile of the placental enzyme digest. The authors conclude that their study gave evidence of heterogeneity among the Pi class GST isozymes of human tissues and supports the ideas of tissue specific expression.
NIOSH-Publication; NIOSH-Grant; Grants-other; Enzymes; Protein-chemistry; Tissue-distribution; Chromatographic-analysis; Peptides
Human Biol Chem and Genetics University of Texas Med BR Dept of Human Biol Chem&gene Galveston, Tex 77550-2774
Other Occupational Concerns; Grants-other
University of Texas Medical Branch, Galveston, Texas