1.8.7.1 coenzyme F420 - 1.8.7.1 NADPH NADPH as an additional electron donor to methyl viologen enhances enzyme activity by 1.6fold 1.8.7.1 NADPH NADPH as an additional electron donor to methyl viologen enhances enzyme activity by 2.8fold 1.8.7.1 NADPH the addition of NADPH to the reaction medium increases enzyme activity by 1.6fold 1.8.7.1 NADPH the addition of NADPH to the reaction medium increases enzyme activity by 2.8fold 1.8.7.1 tungstic acid stimulates activity