THE GLYCATION OF BOVINE LENS BETA(L)-CRYSTALLIN, BETA(S)-CRYSTALLIN AND GAMMA-CRYSTALLIN DEMONSTRATED BY ISOELECTRIC-FOCUSING AND LECTIN STAINING

The aim of the current study is to detect glycation of beta(L)-, beta( S)- and gamma-crystallins in the young bovine lens. To determine which of the crystallins are glycated, we have made isoelectric focusing of the water-soluble crystallins of four bovine lenses of 1.183+/-0.070 years. Samples are stained: (1) with Coomassie Brilliant Blue for prot eins; (2) with the lectin Concanavalin-A, followed by horse-radish per oxidase (HRP) and diaminobenzidine (DAB). Experiments are performed wi th crystallins in native form, in absence of denaturants. The crystall ins are separated by isoelectric focusing into: a-crystallins of high- molecular weight (HM)-, alpha(L)-, beta(H)-, beta(L)-, beta(S)- and ga mma-crystallins. In the lectin staining experiments only HM-, beta(L)- , beta(S)- and gamma-crystallins are positive, whereas the alpha(L)- a nd beta(H)-crystallins do not stain, Though glycation in the bovine le ns is very low, lectin staining is sufficiently sensitive to detect th e various glycated crystallins. (C) 1997 Academic Press Limited.