二肽基肽酶Ⅲ在不同周龄正常大鼠晶状体中的表达  

Expression of dipeptidyl peptidase Ⅲ in normal lenses of rat of different ages

作　　者：安海鸥[1,2] 张辉[1] 秦秀虹[1] 田蕊[1] 窦莹[1] 房学迅[3] 

机构地区：[1]吉林大学第二医院眼科,长春130041 [2]大连大学附属新华医院眼科,116021 [3]吉林大学分子酶学工程教育部重点实验室,长春130021

出　　处：《眼科研究》2010年第3期249-252,共4页Chinese Ophthalmic Research

基　　金：教育部归国留学人员科研启动基金(2005);吉林省科技发展计划(200705233);长春市科技发展计划(03-1188527)资助

摘　　要：目的检测二肽基肽酶Ⅲ(DPPⅢ)在不同周龄大鼠晶状体中的表达。探讨DPPⅢ与年龄相关性白内障发病的关系。方法收集3、6、9、12周龄各15只Wistar大鼠的晶状体并用标准牛血清制成匀浆,采用SDS-PAGE凝胶电泳法检测晶状体中的目标蛋白;采用Western blot法检测DPPⅢ在不同周龄正常大鼠晶状体中的含量变化(半定量并以灰度值表达),并应用蛋白酶活性测定DPPⅢ在不同周龄正常大鼠晶状体中的酶活性变化。应用直线回归法评价DPPⅢ酶活性与鼠龄的关系。结果SDS-PAGE凝胶电泳法测得目标蛋白的相对分子质量为82000。随着正常大鼠周龄的增加,晶状体中DPPⅢ表达的峰灰度值和总灰度值均呈增加趋势。晶状体中DPPⅢ的总酶活性与Wistar大鼠的年龄呈正相关(r=0.99,P<0.05)。结论晶状体中DPPⅢ随年龄的增长表达发生变化,可能与晶状体发育中一些晶状体蛋白的变化有关,推测DPPⅢ可能在年龄相关性白内障的形成过程中参与晶状体蛋白的降解,促进白内障的发展。Background It has been determined that dipeptidyl peptidase Ⅲ （ DPP Ⅲ ） plays an important role in the metabolism and modification of proteins and DPPm of human has highly homologous to rat. Researches have shown that DPPm is associated with the formation of cataract. However, few relevant studies have been reported. Objective The present study is to find out the relationship between the expression of DPP Ⅲ in rat lenses and age-related cataract. Methods Lenses were obtained from general Wistar rats of ages 3,6,9 ,or 12 weeks old （ 10 lenses each ） and homogenized with different concentrations of standard bovine serum. The proteins were resolved using SDS-PAGE gel electrophoresis. Peak concentration and total concentration of DPP Ⅲ protein in lenses from rats of different ages were detected by Western blot. Enzyme activity of DPP Ⅲ was determined by monitoring the amount of dipeptides removed from a special substrate （ Arg-Arg-4mb NA） by measuring the absorbance with UV-2500PC at 525 nm. The relationship between the enzyme activity of DPP Ⅲ in lenses and age of rats was evaluated using regression analysis. Results DPPm was detected at a molecular weight of 82 000 Da. The peak concentration and total concentration of DPPⅢ in normal rat lenses increased with the growth of age. The total protease activity of DPPm in the lenses of rats was correlated with the ages of the rats （ r = 0. 99, P 〈 0.05 ）. Conclusion DPP Ⅲ may be involved in the alteration of crystallin during the development of lenses, and it may play an important role in the formation and aggravation of age- related cataract.

关 键 词：二肽基肽酶Ⅲ 晶状体 年龄相关性白内障 酶活性 

分 类 号：R776.1[医药卫生—眼科]