Glycosylation in vivo of human lens capsule (basement membrane) and diabetes mellitus.

Glycosylation represents a nonenzymatic posttranslational modification of some proteins in vivo. We have investigated possible glycosylation, in vivo, of human lens capsule (basement membrane of lens epithelium) using a colorimetric method. Our study reveals, for the first time, in vivo glycosylation of human lens capsule. Furthermore, the glycosylation of the lens capsule in the diabetics (57.30 +/- 11.26 n moles/mg. protein) is found to be significantly greater than that in their nondiabetic counterparts (29.11 +/- 4.90 n moles/mg. protein) (p less than 0.0005). The present observation represents the first example of increased glycosylation of a basement membrane in the diabetic patients as compared to the nondiabetic controls.