Age-dependent structural changes in intact human lenses detected by synchrotron radiation X-ray scattering. Correlation with Maillard reaction protein fluorescence.
To understand alterations in the spatial organization of the crystallins, the major determinant of lens transparency, the x-ray scattering by intact normal human lenses from individuals 6-82 years of age was measured using synchrotron radiation. The angular dependence of the integrated scattering intensity is consistent with short-range order within the crystallin assemblies. A significant change in the scattering patterns of the lenses occurs after 55 years of age, in parallel with an increase of the fluorescence of the urea-insoluble crystallin fraction. This correlation suggests a gradual derangement of the short-range order as a result of cross-linking of the crystallin subunits by advanced Maillard reaction products that are generated by the continuous reaction of sugars, such as glucose or fructose, with proteins.
Suárez
G
G
New York Medical College, Department of Biochemistry and Molecular Biology, Valhalla, New York 10595.
Oronsky
A L
AL
Koch
M H
MH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002648:Child; D003459:Crystallins / Q000032:analysis*; D006801:Humans; D007908:Lens, Crystalline / Q000254:growth & development / Q000648:ultrastructure*; D008875:Middle Aged; D013050:Spectrometry, Fluorescence; D017356:Synchrotrons; D014961:X-Ray Diffraction / Q000379:methods
D003459:Crystallins