Soluble lens proteins in rats on different sugar diets

Abstract

The soluble lens proteins of rats maintained on normal rat chow, and on diets containing 40% cane sugar, lactose or galactose, were studied by means of paper electrophoresis, agar gel electrophoresis, immunoelectrophoresis, gel filtration chromatography on Sephadex G-100, and ultracentrifugation. Saccharose feeding did not disturb the distribution of the soluble lens proteins analyzed by all of these methods. Lactose, a cataractogenic sugar, given to the animals during the time needed to develop cataracts with a galactose diet, produced only minor changes. In galactose cataracts, important modifications in the soluble lens proteins were found by each one of the methods used. In this condition, a fraction with a higher anodic mobility than the normal α-crystallin group was found on paper and agar gel electrophoresis. On immunoelectrophoresis the extra fraction showed a reaction of identity with one of the normal arcs of the α-crystallin group. Other modifications of the immunoelectrophoretic pattern were also found. The methods which investigate the molecular size, showed a decrease in the low molecular weight proteins, and an increase of the high molecular weight proteins. The possibility of a common feature in different types of cataracts is discussed.