摘要
本文用汞电极（HMDE）二次导数阴极吸附伏安（SD－AdCSV）和碳电极（GCE、CPE）导数循环伏安（FD－CV）法研究了核酸受热、紫外线、超声波和丝裂霉素C（MMC）作用下的变性作用。在0．1mol／L（K2HPO4＋KH2PO4）-0．1mol／LNaCl（pH7．0）废液中，吸附的单股（ss-）和双螺旋（ds-）DNA分别在HMDE上得到特征还原峰P3（-1.56V）和P2（－1.37V，vs.Ag／Agcl），和在碳电极之得到氧化峰A（＋1.08V）及G（+0.78V）。物理和化学因素改变DNA的构型或使它变性时，反映在氧化还原峰形和参数有明显的变化。MMC优先结合ss－DNA，并能插入ds－DNA起交链作用。
Denaturation and damage in matuve DNA (RNA) by therrnal action, ultrasonication, UV-irradiarion and antitumor agent mitomycin C (MMC) actions were studied by means of cathodic/anodic adsorptive stripping voltammetry using second-order differential voltammetric and differential cyclic voltammetric models in combination with HMDE, GCE and CPE electrodes. In the background electrolyte consisted of 0.1 mol/L (K2HPO4+ KH2PO4) -0.1 mol/L NaCl (pH 7.0),the adsorbed double-helical (ds-) and single-strandes (ss-) DNA on HN1DE produce one of their specific reduction peak at P,2-1. 37 V vs. Ag/AgCl, ds-) and P3( -1.56 V. s DNA), respectively, and two oxidation peaks of A (+1. 08 V) and G ( +0.78 V) to. both of adsorbed DNA species on GCF and CPE. When the native DNA was damaged by physical or chemical agents. the voltammogramchanged not only in peak currents. but also in forms and parameters. All of the changes in voltammogram indicated that the double helix DNA might be defected in a certain extent in comformaticn. Reduced MMC must combine with ss-NNA prior to intercolate into or crosslink to ds-DNA by incubation in physiological conditions, since P3 disappeared before p2 on the voltamrnogram. This method may be applied conveliiently to probing the damage in native DNA in vitro.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1996年第4期463-466,共4页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金
关键词
脱氧核糖核酸
变性
伏安法
导数测定
Deoxyribonucleic acid, denaturation, adsorptive volammetry
