van Boekel M A, Hoenders H J
Department of Biochemistry, University of Nijmegen, The Netherlands.
FEBS Lett. 1992 Dec 7;314(1):1-4. doi: 10.1016/0014-5793(92)81446-s.
Water-soluble crystallins were obtained from clear human lenses of different age (4-81-year-olds) and lenses of individuals showing senile or diabetic cataracts. Levels of early glycation products were high in the high molecular weight material (HM) and the alpha-crystallin fractions, compared with beta- and gamma-crystallins. This difference becomes more prominent upon aging. The content of total early glycation products in HM and alpha-crystallin increases clearly with age, whereas levels remain relatively constant in the beta- and gamma-crystallins. There is an elevation of early products in cataractous lenses from diabetic individuals compared with those suffering from senile cataract. Specific non-tryptophan fluorescence (excitation/emission wavelengths 370/440 nm), used as an indicator for late glycation products, increased dramatically with age and was 2-fold higher in the diabetic subjects. Levels of fluorescence decreased in the order HM > alpha- > beta- > gamma-crystallins. The results suggest an increase in glycation rate in alpha-crystallin as a result of aging and diabetes, while the rate of glycation of beta- and gamma-crystallins remains almost constant.
水溶性晶状体蛋白取自不同年龄（4至81岁）的透明人晶状体以及患有老年性或糖尿病性白内障患者的晶状体。与β-晶状体蛋白和γ-晶状体蛋白相比，高分子量物质（HM）和α-晶状体蛋白组分中的早期糖基化产物水平较高。随着年龄增长，这种差异变得更加明显。HM和α-晶状体蛋白中总早期糖基化产物的含量随年龄增长明显增加，而β-晶状体蛋白和γ-晶状体蛋白中的水平则保持相对恒定。与老年性白内障患者相比，糖尿病患者白内障晶状体中的早期产物有所升高。用作晚期糖基化产物指标的特定非色氨酸荧光（激发/发射波长370/440 nm）随年龄增长显著增加，在糖尿病患者中高出2倍。荧光水平按HM>α->β->γ-晶状体蛋白的顺序降低。结果表明，由于衰老和糖尿病，α-晶状体蛋白中的糖基化速率增加，而β-晶状体蛋白和γ-晶状体蛋白的糖基化速率几乎保持不变。
