Lysine-ketoglutarate reductase activity in developing maize endosperm.

Lysine-ketoglutarate reductase activity was detected and characterized in the developing endosperm of maize ( Zea mays L. ). The enzyme showed specificity for its substrates: lysine, α-ketoglutarate, and NADPH. Formation of the reaction product saccharopine was demonstrated. The pH optimum of the enzyme was close to 7, and the K m for lysine and α-ketoglutarate were 5.2 and 1.8 millimolar, respectively.