The proteolytic enzymes of sprouted wheat

Abstract

Using S0rensen''s formaldehyde method of titration, aqueous extracts of sprouted wheat were shown to contain a protease and a dipeptidase acting optimally at pH 4.1, 7.3, and 7.9 on edestin, leucylglycine and glycylglycine, respectively, at 40[degree]. The protease requires a minimum concn. of about 2% edestin for maximum rate of activity. The substrate concn. at which half the maximum reaction velocity is reached corresponds to 0.5% edestin, the course of reaction in the early stages following the Schutz-Arrhenius rule. The critical inactivation temp. of the protease is 54[degree] at pH 6.0. Spontaneous inactivation occurs on storage at 18[degree] with toluene, the inactivation following the course of a monomolecular reaction. Protease activity on edestin is reduced by citrate and chloride ions owing probably to precipitation of substrate. At 18[degree] the protease is more stable in aqueous solution than the dipeptidase, the former losing only half its original activity in 18 days, the latter losing all activity in 5 days.