Nonenzymatic advanced glycation in the lens membranes.

Nonenzymatic advanced glycation was induced in bovine lens membranes. The resulting modified membranes display some changes which were also observed in the advanced glycated crystallins: an increased absorption in the near-UV region, appearance of a strong blue fluorescence (Ex/Em = 370/450 nm), and a subtle change in the near-UV circular dichroism (CD). These changes were also observed in diabetic human lens membranes, but with a less extent in nondiabetic samples. The results indicate that advanced glycation is important in diabetes mellitus, not only to crystallins but also to membrane proteins, both of which generate yellow pigment chromophores that result in lens coloration.