DETERMINATION OF NANOGRAM QUANTITIES OF OSMIUM-LABELED NUCLEIC-ACIDS BY STRIPPING (INVERSE) VOLTAMMETRY
DETERMINATION OF NANOGRAM QUANTITIES OF OSMIUM-LABELED NUCLEIC-ACIDS BY STRIPPING (INVERSE) VOLTAMMETRY
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DOI：
10.1016/0003-2697(83)90002-7
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发表时间：
1983-01-01
影响因子：
2.9
通讯作者：
HUNG, MA
中科院分区：
文献类型：
--
作者：
PALECEK, E;HUNG, MA
修饰的核酸与OsO 4在吡啶的存在下的结果在形成的共价结合的电活性中心的多核苷酸链可检测的极谱（伏安）方法。用锇修饰的DNA [小牛胸腺，大肠杆菌，质粒科尔-1]（DNA-Os）在0和-1.0 V（相对于饱和甘汞电极）之间的宽电位范围内的等待时间内在悬汞电极上积累，并在中性pH下由于阴极方向的扫描而在约-1.2 V处产生充分发展的还原峰。使用差分脉冲溶出（逆）伏安法，可以在相对短的等待时间（1-3分钟）确定纳克量的单链DNA-Os。与单链多核苷酸相比，双链DNA被锇修饰的程度要小得多。双螺旋DNA的修饰程度受DNA分子中单链和扭曲双链区域的存在以及影响DNA构象的环境条件的影响。因此，锇可以用作DNA结构的探针，并且几微克的双螺旋DNA样品就足以进行伏安分析。
Modification of nucleic acids with OsO4 in the presence of pyridine results in a formation of a covalently bound electroactive center in a polynucleotide chain detectable by polarographic (voltammetric) methods. DNA [calf thymus, Escherichia coli, plasmid ColE-1] modified with osmium (DNA-Os) accumulates at the hanging mercury-drop electrode during a waiting time in a wide range of potentials between 0 and -1.0 V (against the saturated calomel electrode) and produce at neutral pH a well-developed reduction peak at about -1.2 V due to scanning in the cathodic direction. Using the differential-pulse stripping (inverse) voltammetry, nanogram quantities of single-stranded DNA-Os can be determined at relatively short waiting times (1-3 min). Double-stranded DNA is modified with osmium to a much lesser extent as compared to single-stranded polynucleotides. The degree of modification of double-helical DNA is influenced by the presence of single-stranded and distorted double-stranded regions in the DNA molecules and by the environmental conditions which influence the DNA conformation. Osmium can thus be used as a probe of the DNA structure, and a few micrograms of double-helical DNA sample suffice for the voltammetric analysis.