Abstract
The effects of vitamins and amino acids on the inhibition of α-amylase activity by riboflavin are reported in this paper. Single vitamin, cysteine and Na_2S_2O_4 respectively inhibits the α-amylase activity under the pH below the optimum of its activity, whereas their inhibition is affected by pH of enzyme solution. Generally the inhibition of α-amylase activity by addition of vitamins to the enzyme solution containing riboflavin is not so severe as the total by individual vitamin, but addition of reducing agent promotes the inhibition of α-amylase activity by riboflavin. It is suggested that tryptophan releases about 20% from the inhibition of α-amylase by riboflavin. Aromatic amino acids also prevent about 10% of the inhibition of α-amylase by riboflavin, while aliphatic amino acids do not show such action.
