抄録
NADH-Methemoglobin reductase was purified 40,000-fold from human erythrocytes in the form of a simple protein without a prosthetic group or a metal, having the molecular weight of about 30,000. The enzyme showed NADH-diaphorase activity, and reduced metmyoglobin and ferric cytochrome c as quickly as methemoglobin. The rate of reduction of cytochrome b5 by the enzyme is higher than that of methemoglobin, and the methemoglobin reduction is augumented in the presence of a catalytic amount of cytochrome b5. In view of Kms for NADH and methemoglobin, the enzyme seems to play a major role in the reduction of methemoglobin in erythrocytes.
