Studies on Respiratory Enzymes in Rice Kernel

Abstract

The physicochemical properties and chemical constituents of the blue protein from rice bran were investigated. The blue protein was a copper-containing glycoprotein, the molecular weight of which was found to be 18, 300 Daltons by the sedimentation equilibrium method assuming the partial specific volume 0.72cm3g-1. The hexose and pentose contents were 5.49 and 4.01g per 100g protein respectively. The copper content was 0.38%, which corresponded to 1.09 atoms per one molecule of the protein. The electron spin resonance spectrum showed that the copper was in a cupric state. The standard oxidation-reduction potential of the copper was found to be +275 mV at 20°C and at pH 7.39. The visible and near infrared absorption maxima were found at 450, 600 and 890mμ, and the 450mμ band was optically active in the optical rotatory dispersion exhibiting a large Cotton effect.