摘要
目的：观察维生素Ｃ（ＡＳＡ）在晶体蛋白发生光氧化时的作用及其机制。方法：牛晶体蛋白溶液在加入或不加入ＡＳＡ时，于５天内共接受２００ｍＪ／ｃｍ２紫外线Ｂ（ＵＶＢ）照射，接着在３７℃继续孵育至第３周，然后测定晶体蛋白的非色氨酸荧光、游离巯基和进行蛋白电泳分析。结果：ＡＳＡ在溶液中易被氧化，蛋白溶液中加入ＡＳＡ促使晶体蛋白的非色氨酸荧光产生明显增强，导致非二硫键聚合形成，对晶体蛋白的游离巯基减少有保护作用。有ＡＳＡ时，ＵＶＢ照射更易导致晶体蛋白形成非二硫键聚合。结论：体外溶液中的ＡＳＡ易与晶体蛋白发生糖化作用，同时作为抗氧化剂能保护晶体蛋白的游离巯基不被氧化。
In order to explore the effects of ascorbic acis(ASA)on the photo-oxidation of
crystallin.Bovine crystalline solution mixed with or without ASA were irradiated with
200mJ/cm 2 of UVB,and then incubated at 37℃ for three weeks.Measurement of
non-tryptophan fluorescence,free sulfhydryl of protein and SDS-polyacrylamide
electrophoresis were performed to compare with the alteration of lens protein under
different treatments.The results showed that ASA is easy to be oxidized in solution.It
promotes the production of the non-tryptophan fluorescence and the aggregation of
crystallins.Irradiating the mixture of lens protein and ASA with UVB can result in
obvious aggregation of crystallins through mainly non-disulfide bond.ASA can protect
protein sulfhydryl against photo-oxidation.The present study suggests that ASA is easy
to induce the glycation of crystallins in solution,and as an antioxidant,it can prevent the
oxidation of protein sulfhydryls.
出处
《眼科》
CAS
1999年第3期161-164,共4页
Ophthalmology in China
基金
广东省自然科学基金
