Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India.
Amino Acids. 2012 Sep;43(3):1311-22. doi: 10.1007/s00726-011-1204-8. Epub 2011 Dec 24.
This study investigates the effect of pentose sugars (ribose and arabinose) on the structural and chemical modifications in glucose oxidase (GOD) as well as genotoxic potential of this modified form. An intermediate state of GOD was observed on day 12 of incubation having CD minima peaks at 222 and 208 nm, characteristic of α-helix and a few tertiary contacts with altered tryptophan environment and high ANS binding. All these features indicate the existence of molten globule state of the GOD with ribose and arabinose on day 12. GOD on day 15 of incubation forms β structures as revealed by CD and FTIR which may be due to its aggregation. Furthermore, GOD on day 15 showed a remarkable increase in Thioflavin T fluorescence at 485 nm. Comet assay of lymphocytes and plasmid nicking assay in presence of glycated GOD show DNA damage which confirmed the genotoxicity of advance glycated end products. Hence, our study suggests that glycated GOD results in the formation of aggregates and the advanced glycated end products, which are genotoxic in nature.
本研究调查了戊糖（核糖和阿拉伯糖）对葡萄糖氧化酶（GOD）结构和化学修饰的影响，以及这种修饰形式的遗传毒性潜力。在孵育的第 12 天观察到 GOD 的中间状态，其 CD 最小峰出现在 222nm 和 208nm，特征为α-螺旋和一些与色氨酸环境改变和高 ANS 结合有关的三级接触。所有这些特征表明，在第 12 天，核糖和阿拉伯糖存在 GOD 的无定形球蛋白状态。在孵育的第 15 天，GOD 通过 CD 和 FTIR 形成 β 结构，这可能是由于其聚集。此外，GOD 在第 15 天在 485nm 处显示出硫黄素 T 荧光的显著增加。存在糖基化 GOD 的淋巴细胞彗星试验和质粒切口试验显示 DNA 损伤，这证实了晚期糖基化终产物的遗传毒性。因此，我们的研究表明，糖基化 GOD 导致形成聚集物和高级糖基化终产物，这些产物具有遗传毒性。
