Substrate glutathione dehydrogenase

Table 15.23. Substrate specificity of glutathione dehydrogenase (GSH-DH) from wheat...

Similar sex and species differences have been described for glutathione S-transferase activity. The activities of glutathione-S-transferase (using dichloronitrobenzene as a substrate) were two- to three-fold higher in the livers of male B6C3F] mice, compared with female mice and Fischer 344 rats of both sexes, and about seven-fold higher than in male mouse kidney. Neither hepatic nor renal fonnaldehyde dehydrogenase showed any sex difference in either species, but the activities in mouse liver were about two-fold... 

Whilst these observations point to a potentially important cell-regulatory role for HNE, little is known about factors that control the rate of its production. Clearly a prerequisite is the formation of cellular lipid hydroperoxides, but although levels of those can apparently be modulated by serum factors there is a need to explore mechanisms, possibly enzymatic, whereby HNE levels might be tightly regulated. In this context it is known that HNE can serve as a substrate for glutathione transferase [64], or aldehyde dehydrogenase [66] ... 

The three enzymes are quite specific for their respective pyridine nucleotide substrates. Under conditions normally used for assay, lipoamide dehydrogenase is less than % as active with NADPH as with NADH IS) and thioredoxin reductase is less than 1% as active with NADH as with NADPH 36, Sff). Lipoamide dehydrogenase can transfer electrons to a number of NAD analogs 37). Yeast glutathione reductase is quite specific for NADPH 60), but the erythrocyte enzyme is 20% as active with NADH as with NADPH under the conditions of the standard assay 30,40,61). 

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