[On the mechanism of inhibition of mitochondrial glutamate-oxalacetate-transaminase in SO2-fumigated peas].

The effect of SO2-fumigation on the mitochondrial and cytoplasmic form of GOT in peas has been tested. GOT is represented by two distinct proteins in peas and therefore its activity may be taken as a measure of action of certain effectors on different components of the cell. An optical method for the direct measurement of GOT activity in crude plant extracts has been established. Using this method it could be shown that the mitochondrial GOT in SO2-fumigated peas is inhibited while at the same time the cytoplasmic form of the enzyme remains uneffected. The mechanism of inhibition of mitochondrial GOT by SO 3 (--) /HSO 3 (-) has been analyzed and could be shown to be of the mixed type. This investigation confirms an earlier observation that differential effects of SO2 on single compartments of the cell may occur.