Acidic peptides of the lens. 2. The use of ion-exchange resins as molecular sieves

Abstract

The tri-peptide, ophthalmic acid, was isolated in the crystalline state from calf lens. The isolation depends on the use of ion-exchange resins as molecular sieves: the peptide is selectively adsorbed from the dilute solution without interference from proteins. Further fractionation was effected with ion-exchange resins and paper chromatography. Another tripeptide (norophthalmic acid) has been identified: it is gamma-glutamylalanylglycine.