Abstract
Phosphorylase activity could not be detected in sweet potato or barley extract where β-amylase activity was high. The mechnism of the inhibition of phosphorylase activity by β-amylase was found to be due to the destruction of added soluble starch as an activator by the action of β-amylase. To demonstrate directly the presence of phosphorylase in the sweet potato extract, it was attempted to purify phosphorylase from the sweet potato extract by means of ammonium sulphate. A preparation active in phosphorylase but with little β-amylase activity was obtained.
