年龄和离体翻译后修饰对兔α-晶状体蛋白分子伴娘活性的影响

Effects of aging and post-translational modifications on molecular chaperone-like activity of α-crystalline

目的 探讨年龄和离体翻译后修饰对兔α 晶状体蛋白分子伴娘活性的影响。方法(1)用凝胶过滤法分离幼年、成年和老年 3个组兔水溶性晶状体蛋白 ,观察不同年龄兔α 晶状体蛋白抑制 β low晶状体蛋白凝集和变性作用的程度差异。 (2 )孵育α 晶状体蛋白使之氧化和糖基化 ,观察修饰和未修饰的α 晶状体蛋白抑制 β low晶状体蛋白凝集和变性作用的程度差异。 结果 (1) 3个年龄组α 晶状体蛋白抑制热诱导 β low晶状体蛋白凝集和变性作用的程度差异有显著意义 (F =2 9 10 0 ,P <0 0 1) ,成年组兔α 晶状体蛋白的抑制作用强于老年组 ,弱于幼年组 ,差异有显著意义(q =4 192 4 ,4 3339;P <0 0 5 )。 (2 )离体氧化和糖基化修饰的α 晶状体蛋白抑制 β low晶状体蛋白凝集和变性的作用均弱于未修饰的α 晶状体蛋白 ,差异有显著意义 (q =2 6 9171,11 6 4 0 4 ;P <0 0 1)。结论 (1)随着年龄的增加 ,兔α 晶状体蛋白的分子伴娘活性呈下降趋势。 (2 )离体翻译后修饰可使兔α

Objective To study the affects of aging and post translational modifications in vitro on rabbit α crystalline molecular chaperone like activity. Methods (1) Rabbits with three different ages (3 days old, 3 months old and 2 years old) were chosen in the study. The water soluble crystalline in the three age groups was purified by Sephadex G 200 gel filtration. Different abilities of them to protect β low crystalline from thermal aggregation were observed. (2) Incubation of α crystalline with fructose or with H 2O 2 was carried out for 24 hours. Fructose was used for glycosylation and H 2O 2 for oxidation of α crystalline. Different abilities of modified and unmodified α crystalline to protect β low crystalline from aggregation were observed. Results (1) α Crystalline of 3 months old rabbit has more ability to protect β low crystalline from aggregation than 2 years old rabbit but less ability than 3 days old rabbit. (2) The glycosylated and oxidized α crystalline have less ability to protect β low crystalline from aggregation than the unmodified α crystalline. Conclusions (1) With aging rabbit α crystallines gradually lose their molecular chaperone like ability. (2) The modified α crystallines show the loss in molecular chaperone like ability the most.