Age-related variations in the distribution of crystallins within the bovine lens.
The native water-soluble proteins of equator, anterior cortex, posterior cortex and nucleus from bovine lenses in the age range 0.3-33.7 years were analyzed by high-pressure gel-permeation chromatography and high-pressure ion-exchange chromatography. Unlike the equator and cortices, the nucleus shows a gradual decrease in alpha-crystallin proportion with age which is not compensated for by an increase in HM-crystallin. The beta 6H-crystallin species, almost the only beta H-component in the youngest lens, is largely replaced by at least four fractions with higher and lower molecular weights in the older lenses. In the nucleus a beta L-component (39,000 MW) increasingly seems to replace the major beta L-crystallin (beta 2L, 50,000 MW). Moreover, a switch in the synthesis of monomeric crystallins is demonstrated. This study clearly reveals an age-related increase in the size heterogeneity of the native soluble crystallins with age.
D000375:Aging; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003459:Crystallins / Q000032:analysis*; D007904:Lens Cortex, Crystalline / Q000032:analysis; D007907:Lens Nucleus, Crystalline / Q000032:analysis; D008970:Molecular Weight
D003459:Crystallins