Over-Expression, Purification, and Characterization of Plant LeGST01, the Mammalian GST-Omega Homolog that Interacts with LeTPX1 from a Tomato cDNA Library

The study focuses on an in vivo GST- omega homologue (pCRT7/TPxII intB4) over-expression, purification and characterization. Experiments purport to characterize the antioxidant activity of the LeTPx1, the interacting glutathione S-transferases BI-GST/GPx, LeGST-T1, T2, T3, T4, T5 and the mammalian inhibitor of apoptosis Bcl-2. Upon specific expression, the proteins exerted, differential protective effects in yeast cells treated with lethal doses of the prooxidants hydrogen peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. The antioxidant activity of LeTPx1 was highest against the cumene hydroperoxide. The overexpressing GST (omega) homologue TPxintB4 (Baier and Dietz, 1999) which share a considerable homology of the mammalian GST-omega1. In conclusion, the work shows that yeast parental strains are extremely sensitive to very low concentrations (0.2mM) of Cumenehydroperoxide. However, after applying the different antioxidants; it appears that the smallest concentrations t to be tolerated.