The glycation of bovine lens beta(L)-, beta(S)- and gamma-crystallins 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 proteins; (2) with the lectin Concanavalin-A, followed by horse-radish peroxidase (HRP) and diaminobenzidine (DAB). Experiments are performed with crystallins in native form, in absence of denaturants. The crystallins are separated by isoelectric focusing into: a-crystallins of high-molecular weight (HM)-, alpha(L)-, beta(H)-, beta(L)-, beta(S)- and gamma-crystallins. In the lectin staining experiments only HM-, beta(L)-, beta(S)- and gamma-crystallins are positive, whereas the alpha(L)- and beta(H)-crystallins do not stain, Though glycation in the bovine lens is very low, lectin staining is sufficiently sensitive to detect the various glycated crystallins. (C) 1997 Academic Press Limited.