Isolation and Characterization of Malic Enzyme from the Pupa of Bombyx mori

Abstract

Malic enzyme, which requires NADP⁺ as a coenzyme, was isolated and purified from pupae of the silkworm, Bombyx mori. The purified enzyme appeared homogeneous and had a molecular weight of 195, 000 on polyacrylamide gel electrophoresis. The optimum pH for the oxidative decarboxylation of malate, measured in terms of the increase of NADPH (MH activity) and CO₂ (MC activity), was pH 7.5, while that for the decarboxylation of oxaloacetate measured in terms of the increase of CO₂ (OC activity) was pH 4.6. Several differences between MH and OC activity were investigated.