Effect of Ascorbic Acid on Copper-binding Proteins in Guinea Pigs

Abstract

In guinea pig, a large part of copper is stored on liver in the form of copper-binding proteins. To clarify the effect of ascorbic acid on the biosynthetic activity of copper-binding protein, the following experiment was carried out. The supernatant of guinea pig liver was fractionated by Sephadex G-75 column chromatography. Two peaks of copper-binding protein were observed in both scorbutic and normal guinea pigs. The peak I (M.W.=more than 70,000) was assumed as ceruloplasmin or serum albumin and peak 11 (M.W.=about 10,000) as metallothionein. In normal guinea pigs, a large fraction of peak I was observed, while a large fraction of peak 11 appeared in scorbutic guinea pigs. By these results, we concluded that biosynthetic activity of metallothionein increased in scorbutic guinea pigs for the purpose of eliminating excess copper.