STUDIES ON THE CRYSTALLINE LENS

Abstract

PREVIOUS experiments¹ with lenses cultured in vitro with labeled glycine have shown that the tripeptide glutathione turns over continuously, being degraded into its component amino acids and resynthesized at similar rates. A significant amount of labeled glycine in these experiments was also found in the lens proteins. The present study is concerned with whether the lens proteins are similarly in a state of flux and whether interconversions of amino acids occur in the lens. No previous studies of the interconversions of amino acids and the turnover of lens proteins have been made, nor had a detailed analysis of the amino acid composition of lens proteins been reported at the time these studies were performed.² There has been a recent investigation, however, on the oxidative metabolism of amino acids. De Vincentiis and Auricchio³ demonstrated the ability of the lens to oxidize several amino acids to keto acids, which,