Department of Biochemistry, Faculty of Life Sciences, AMU, Aligarh, U.P., India; Department of Biosciences, Integral University, Lucknow, U.P., India.
Department of Biochemistry, Faculty of Life Sciences, AMU, Aligarh, U.P., India.
Int J Biol Macromol. 2020 Nov 15;163:1844-1858. doi: 10.1016/j.ijbiomac.2020.09.083. Epub 2020 Sep 19.
Non-enzymatic glycation tempted AGEs of proteins are currently at the heart of a number of pathological conditions. Production of chemically stable AGEs can permanently alter the protein structure and function, concomitantly leading to dilapidated situations. Keeping in perspective, present study aims to report the glycation induced structural and functional modification of a cystatin type isolated from rai mustard seeds, using RSC-glucose and RSC-ribose as model system. Among the sugars studied, ribose was found to be most potent glycating agent as evident from different biophysical assays. During the course of incubation, RSC was observed to pass through a series of structural intermediates as revealed by circular dichroism, altered intrinsic fluorescence and high ANS binding. RSC incubation with ribose post day 36 revealed the possible buildup of β structures as observed in CD spectral analysis, hinting towards the generation of aggregated structures in RSC. High thioflavin T fluorescence and increased Congo red absorbance together with enhanced turbidity of the modified form confirmed the aggregation of RSC. The study further revealed anti-glycation and anti-aggregation potential of amino acids; aspartic acid and arginine as they prevented and/or slowed down the process of AGEs and β structure buildup in a concentration dependent manner with arginine proving to be the most effective one.
非酶糖基化诱使蛋白质的 AGEs 目前是许多病理状况的核心。化学稳定的 AGEs 的产生可以永久改变蛋白质的结构和功能，同时导致破败的情况。从目前的研究来看，本研究旨在报告使用 RSC-葡萄糖和 RSC-核糖作为模型系统，对从芥菜种子中分离出的一种胱抑素型进行糖基化诱导的结构和功能修饰。在所研究的糖中，核糖被发现是最有效的糖基化剂，这从不同的生物物理测定中可以明显看出。在孵育过程中，通过圆二色性、内在荧光变化和高 ANS 结合，观察到 RSC 经历了一系列结构中间体。RSC 与核糖孵育 36 天后，CD 光谱分析显示可能形成 β 结构，表明 RSC 中形成了聚集结构。高硫代黄素 T 荧光和刚果红吸收增加以及修饰形式的浊度增加共同证实了 RSC 的聚集。该研究进一步揭示了氨基酸（天冬氨酸和精氨酸）的抗糖基化和抗聚集潜力；因为它们以浓度依赖的方式防止和/或减缓 AGEs 和 β 结构形成的过程，其中精氨酸被证明是最有效的一种。
