2-甲基1,4-萘醌激发三重态与核酸反应的电子自旋共振自旋消减法研究  

ESR spin elimination research on reaction of triplet state of VK_3 with nucleic acid derivatives

作　　者：杜富强[1,2] 刘玉侠[1,2] 屠铁城[1] 林维真[1] 

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院研究生院,北京100049

出　　处：《辐射研究与辐射工艺学报》2009年第5期265-268,共4页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金(30770506;20133020)资助

摘　　要：应用电子自旋共振(Electron spin resonance,ESR)自旋消减法,研究了内源性光敏剂2-甲基-1,4萘醌(VK3)的激发三重态(3VK3*)与核酸及其组分的反应性顺序,得到3VK3*与四个核苷及四个单核苷酸的反应性顺序为Gua>Ade>Cyt>Thy,dGMP>dAMP>dCMP>TMP。结果与早前采用激光光解瞬态吸收光谱研究3VK3*氧化DNA,测得的DNA及其组分阳离子自由基生成速率常数、核苷及核苷酸的氧化还原电位排序相一致。对3VK3*与几种富含鸟嘌呤(G)的寡聚核苷酸:端粒DNA重复序列、端粒酶RNA亚基模版及其L6-P6发夹序列反应的ESR自旋消减法研究结果表明,其反应性大小与寡聚物中鸟嘌呤含量正相关,其中与端粒DNA的反应性最强。In order to study the reaction of triplet state of VK3 with nucleic acid derivatives, the ESR （Electron spin resonance） spin elimination has been used with 4-oxo-TEMPO as spin trap. The reactivities of 3VK3＊ with nu-cleosides, nucleotides, and models of telomeric DNA, template of telomerase RNA and its L6-P6 region have been confirmed respectively. The results show that the tendency of reaction of 3VK3＊ with nucleosides is Gua〉Ade〉Cyt〉Thy, meanwhile dGMP〉dAMP〉dCMP〉 TMP for reaction of 3VK3＊ with deoxy-nucleotides, and the one for reaction of 3VK3＊ with telomeric DNA is the highest in polynucleotides. This is highly accordant with both of their corresponding rate constants determined by laser flash photolysis and their oxidation-reduction potentials. It also shows that the reactivity of 3VK3＊ with polynucleotides is directly proportional to their G amount.

关 键 词：2-甲基-1 4-萘醌 激发三重态 电子自旋共振自旋消减法 

分 类 号：TS207.7[轻工技术与工程—食品科学] O644.12[轻工技术与工程—食品科学与工程]