The elevated lenticular level of methylglyoxal (MGO) in diabetic patients is an important risk factor for the development of age-related (senile) cataract disorders. Carnosine (β-alanyl L-histidine), a natural antioxidant dipeptide product, has been indicated to prevent the development of cataract diseases. Therefore, it is possible that the anti-cataract activity of this naturally occurring compound is mediated by its anti-glycoxidation effect. In this study, the eye lens proteins were treated with MGO in the presence of carnosine. Then, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and several spectroscopic evaluations were used with the aim to investigate the possible inhibitory activity of carnosine against the MGO-induced structural damages of eye lens proteins. Our results indicated that MGO causes a substantial structural alteration in the lens proteins. The results of fluorescence assessments also suggested that MGO-induced structural changes were accompanied with the formation of additional chromophores in the protein structure. Also, in the presence of carnosine, a notable reduction in the protein structural damages was observed. Our results may highlight an important protective role of carnosine against MGO-induced structural insults in the lens proteins. This study suggests carnosine supplementation as a possible preventive strategy against development of the diabetic cataracts in human.

中文翻译：

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肌肽可防止甲基乙二醛在晶状体晶体中引起的不同结构损伤。

糖尿病患者的甲基乙二醛（MGO）的双凸透镜水平升高是与年龄相关的（老年）白内障疾病发展的重要危险因素。肌肽（β-丙氨酰L-组氨酸）是一种天然的抗氧化剂二肽产品，已被证明可以预防白内障疾病的发展。因此，该天然存在的化合物的抗白内障活性可能是由其抗糖氧化作用介导的。在这项研究中，眼肌蛋白在肌肽存在下用MGO处理。然后，使用十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）分析和几种光谱学评估，旨在研究肌肽对MGO引起的眼镜蛋白结构损伤的抑制作用。我们的结果表明，MGO导致晶状体蛋白发生实质性结构改变。荧光评估的结果还表明，MGO诱导的结构变化伴随着蛋白质结构中其他发色团的形成。另外，在肌肽存在下，观察到蛋白质结构损伤的明显减少。我们的结果可能突出了肌肽对MGO引起的晶状体蛋白结构性损伤的重要保护作用。这项研究表明补充肌肽可以作为预防人类糖尿病性白内障发展的可能策略。荧光评估的结果还表明，MGO诱导的结构变化伴随着蛋白质结构中其他发色团的形成。另外，在肌肽存在下，观察到蛋白质结构损伤的明显减少。我们的结果可能突出了肌肽对MGO诱导的晶状体蛋白结构性损伤的重要保护作用。这项研究表明补充肌肽是预防人类糖尿病性白内障发展的一种可能的预防策略。荧光评估的结果还表明，MGO诱导的结构变化伴随着蛋白质结构中其他发色团的形成。另外，在肌肽存在下，观察到蛋白质结构损伤的明显减少。我们的结果可能强调肌肽对MGO引起的晶状体蛋白结构性损伤的重要保护作用。这项研究表明补充肌肽可以作为预防人类糖尿病性白内障发展的可能策略。