ESTIMATION OF GENOMIC COMPLEXITY, HETEROLOGOUS EXPRESSION, AND ENZYMATIC CHARACTERIZATION OF MOUSE GLUTATHIONE-S-TRANSFERASE MGSTA4-4 (GST-5.7)

Citation
P. Zimniak et al., ESTIMATION OF GENOMIC COMPLEXITY, HETEROLOGOUS EXPRESSION, AND ENZYMATIC CHARACTERIZATION OF MOUSE GLUTATHIONE-S-TRANSFERASE MGSTA4-4 (GST-5.7), The Journal of biological chemistry, 269(2), 1994, pp. 992-1000
Citations number
56
Categorie Soggetti
Biology
ISSN journal
00219258
Volume
269
Issue
2
Year of publication
1994
Pages
992 - 1000
Database
ISI
SICI code
0021-9258(1994)269:2<992:EOGCHE>2.0.ZU;2-3
Abstract
We have previously isolated a cDNA clone for a unique mouse lung gluta thione S-transferase, mGSTA4-4 (GST 5.7) (Zimniak, P., Eckles, M. A., Saxena, M., and Awasthi, Y. C. (1992) FEBS Lett. 313,173-176). By geno mic Southern blotting and polymerase chain reaction single strand conf ormation polymorphism analysis we have now demonstrated the presence o f at least two mGSTA4-related genes in the mouse. The heterogeneity of mGSTA4-4 was further examined by comparing the structural and kinetic properties of mGSTA4-4 isolated from mouse lung with those of recomhi nant recmGSTA4-4 expressed in Escherichia coli. Except for the isoelec tric point, the physical properties of the two proteins were indisting uishable. Western blots using antibodies against rec-mGSTA4-4 have sho wn selective expression of the enzyme in mouse tissues. Even though th e substrate specificity profiles of the tissue-isolated and recombinan t enzymes, which point to a role of mGSTA4-4 in the detoxification of lipid peroxidation products, were generally similar, significant diffe rences were observed with selected substrates. The existence of functi onally distinct forms of mGSTA4-4 and the presence of more than one ge ne strongly suggest that the previously observed differences in proper ties of mGSTA4-4 isolated from various mouse tissues (Awasthi, S., Sin ghal, S. S., Srivastava, S. K., and Awasthi, Y. C. (1993) Arch. Bioche m. Biophys. 301, 143-150) may be due to tissue-specific expression of mGSTA4-related genes.