Changes in lens protein in concentric fractions from individual normal XXXX lenses.

@entity1 @entity3208 @entity1133 @entity2975 @entity12360 @entity214
The @entity12360 ( @entity12360 ), @entity1133 soluble (US) and @entity1133 insoluble (UI) fractions from individual @entity1 lenses 1.8 to 65 years of age were isolated from concentric fiber layers. In lenses younger than 19 years, a uniform distribution in the amount of @entity12360 , US and UI fractions was found throughout the entire lens. These fractions represent 83, 11.5 and 5.5%, respectively, of the lens dry weight. This composition was observed with the cortical fibers of all lenses examined up to the 65-year old. In the nuclear fiber layers, the proportion of US protein gradually increases in the third to fourth decade of lens growth and appears to have reached a maximum representing 22-24% of the nuclear fiber mass in 50-year and older lenses. A large increase in the amount of the UI fraction to 30% of the fiber mass was observed in lenses between the 5th and 6th decade of lens growth. The change from the cortical to nuclear composition occurs in a narrow region of the lens which becomes more peripheral with aging. The cortical @entity12360 fractions were characterized by well defined @entity2975 gel bands in @entity3208 ( @entity214 ). Those of the nuclear fibers were broadened, especially in the 27/29 and 16/18 kilodalton (KD) region. The disappearance of the 20/22 KD bands in the inner cortical and nuclear fibers cannot be accounted for by the small increase in protein insolubilization in these regions of lenses 40 years or younger.
