The Partial Purification and Properties of a Human Erythrocyte 4-Nitroacetophenone Reductase

Abstract

1. A soluble enzyme which catalyses the NADPH-dependent reduction of 4-nitroacetophenone to 4-nitrophenylmethylcarbinol has been partially purified from human erythrocytes.

2. Inter-individual or intra-individual differences in the enzymic activity were small except for very low activity observed in one subject with glucose 6-phosphate dehydrogenase deficiency resulting in decreased levels of NADPH.

3. The enzyme was inactivated above 50° or on storage at 4° for longer than 24 h. The pH optimum was between 7·0-8·0.

4. The enzyme has been differentiated from NADPH-methaemoglobin reductase, NADPH-cytochrome c reductase, glutathione reductase, α, β-unsaturated ketone reductase and aromatic α-keto acid reductase activities, but similarities exist between this enzyme and a rabbit kidney cortex aromatic aldehyde/ketone reductase.