Cloning and expression of a novel Mu class murine glutathione transferase isoenzyme.

摘要: The present study describes the cDNA cloning, expression and characterization of a novel Mu class murine glutathione transferase (GST) isoenzyme. Screening library from small intestine female A/J mouse using consensus probes derived GST genes (mGSTM1-mGSTM5) resulted in isolation full-length clone previously unknown gene (designated as mGSTM7). choice tissue was based on our previous identification potentially deduced amino acid sequence mGSTM7, which comprises 218 residues, exhibited about 67-78% identity with other GSTs. Recombinant mGSTM7-7 cross-reacted anti-(GST Mu) antibodies, but not Alpha) or Pi) antibodies. pI reverse-phase-HPLC elution profile recombinant were different those substrate specificity also compared Interestingly, mGSTM7 had higher human isoenzyme hGSTM4 (87% 94% similarity sequence) than any known Specific activities GSTM4-4 comparable towards several substrates. For example, similar to hGSTM4-4, poorly active catalysing GSH conjugation 1-chloro-2,4-dinitrobenzene ethacrynic acid, lacked activity 1,2-dichloro-4-nitrobenzene 1,2-epoxy-3-(p-nitrophenoxy)propane. These results suggested that hGSTM4-4 might be counterpart GSTM7-7. Reverse transcription-PCR analysis mGSTM7-specific primers revealed is widely expressed tissues mice, including liver, forestomach, lung, kidney, colon spleen.