| Five enzyme systems were studied : aconitase ( EC 4 . 2 . 1 . 3 ) , aspartate aminotransferase ( EC 2 . 6 . 1 . 1 ) , glucose phosphate isomerase ( EC 5 . 3 . 1 . 9 ) , lactate dehydrogenase ( EC 1 . 1 . 1 . 27 ) , and phosphoglucomutase ( EC 2 . 7 . 5 . 1 ) . ^^^ |