Dutta Udayan, Cohenford Menashi A, Dain Joel A
Department of Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Anal Biochem. 2007 Jan 15;360(2):235-43. doi: 10.1016/j.ab.2006.09.016. Epub 2006 Oct 12.
Advanced glycation end products (AGEs) play a significant role in the pathophysiology of diabetes leading to such conditions as atherosclerosis, cataract formation, and renal dysfunction. While the formation of nucleoside AGEs was previously demonstrated, no extensive studies have been performed to assess the effect of AGEs on DNA structure and folding. The objective of this study was to investigate the nonenzymatic glycation of two DNA oligonucleotide duplexes with one duplex consisting of deoxy-poly(A)15 and deoxy-poly(T)15 and the other consisting of deoxy-poly(GA)15 and deoxy-poly(CT)15. With D-glucose, D-galactose, D/L-glyceraldehyde, and D-glucosamine serving as the model glycating carbohydrates, D-glucosamine was found to exhibit the greatest effect on the stability and structure of the oligonucleotide duplexes, a finding that was confirmed by circular dichroism. The nonenzymatic glycation of deoxy-poly(AT) by D-glucosamine destabilized the deoxy-poly(AT) structure and changed its conformation from A form to X form. D-glucosamine also altered the conformation of deoxy-poly(GA)15 and deoxy-poly(CT)15 from A form to B form. Capillary electrophoresis and ultraviolet and fluorescence spectroscopy revealed that, of the various purines and pyrimidines, 2'-deoxyguanosine and guanine were most reactive with D-glucosamine. The nonenzymatic modification of nucleic acids warrants further investigation because this phenomenon may occur in vivo, altering DNA structure and/or function.
晚期糖基化终产物（AGEs）在糖尿病的病理生理学中起着重要作用，可导致动脉粥样硬化、白内障形成和肾功能障碍等病症。虽然之前已证实核苷AGEs的形成，但尚未进行广泛研究来评估AGEs对DNA结构和折叠的影响。本研究的目的是研究两种DNA寡核苷酸双链体的非酶糖基化，其中一种双链体由脱氧聚（A）15和脱氧聚（T）15组成，另一种由脱氧聚（GA）15和脱氧聚（CT）15组成。以D-葡萄糖、D-半乳糖、D/L-甘油醛和D-葡萄糖胺作为模型糖化碳水化合物，发现D-葡萄糖胺对寡核苷酸双链体的稳定性和结构影响最大，这一发现通过圆二色性得到证实。D-葡萄糖胺对脱氧聚（AT）的非酶糖基化使脱氧聚（AT）结构不稳定，并将其构象从A形式转变为X形式。D-葡萄糖胺还将脱氧聚（GA）15和脱氧聚（CT）15的构象从A形式改变为B形式。毛细管电泳以及紫外和荧光光谱显示，在各种嘌呤和嘧啶中，2'-脱氧鸟苷和鸟嘌呤与D-葡萄糖胺反应性最强。核酸的非酶修饰值得进一步研究，因为这种现象可能在体内发生，改变DNA的结构和/或功能。
