Reducing-agents-mediated Solubilization and Activation of Debranching Enzyme (Pullulanase) in Rice Flour

Abstract

  The effects of reducing agents on solubilization and activation of the debranching enzyme (pullulanase) were examined using rice flour. The activity of the debranching enzyme was observed in a buffer solution (pH 7.5) in which rice flour was incubated together with thiol-reducing reagents, (dithiothreitol, 2-mercaptoethanol etc.), but there was only low activity in the absence of reducing agents. Immunochemical measurement and the specific activity of the enzyme showed that the activation caused by the reductant was due to solubilization of the enzyme protein besides the enzyme activation.