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A Velocity-Gradient Flow Cell for Raman and Emission Spectroscopy of a DNA-Drug Solution

用于 DNA 药物溶液拉曼和发射光谱分析的速度梯度流动池

基本信息

批准号：
62840014
负责人：
TSUBOI Masamichi
金额：
$ 2.69万
依托单位：
Iwaki-Meisei University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1989
项目状态：
已结题

项目摘要

The purpose of this work is to construct a new instrument with which one can examine the geometry of a DNA-Drug complex in a solution.In ordinary solutions, the molecules are randomly oriented. In a spectroscopic measurement on such a solution, therefore, information on the anisotropic properties of the molecules in question is obscured. Thus it is desirable to have molecules oriented in solution. This is known to be possible for the DNA duplex by placing its solution in a flow with a velocity gradient of 10^3 cm s^<-1>/cm order of magnitude. Wada and Kozawa (J.Polymer Sci.,A2, 853 (1964)), for example, produced such a velocity gradient in the flow of solution placed in the gap between two coaxial cylinders, one of which was rapidly rotated. They examined the anisotropy of the 260 nm absorption of DNA In the present study, a similar technique has been applied to Raman and fluorescence spectroscopy.A DNA solution was placed in the gap (1 mm) between two coaxial cylinders; the inside diameter of the outer cylinder was 12 mm, and the outside diameter of the inner cylinder was 10 mm. When the inside cylinder was rotated at 2500 revolutions per minute, a sufficiently large velocity gradient of the liquid flow was produced across the gap so that the DNA molecules were oriented along the flow direction. Anisotropy of the Raman scatterings of the DNA molecule was examined by passing an exciting laser beam into the gap from the bottom of the cylinder in the direction parallel to the cylinder axis. An antitumor drug, aclacinomycin A (HCl salt), was added to the DNA solution, and the anisotropy of its emission and Raman spectra was also examined. It has been established that aclacinomycin binds to DNA with its chromophore oriented parallel to the base plane of the DNA duplex.Thus, the newly constructed instrument proved to be powerful for elucidating the geometry of a DNA-drug interaction.

这项工作的目的是构建一种新的仪器，人们可以用它来研究DNA-药物络合物在溶液中的几何形状。因此，在对这种溶液的光谱测量中，关于所讨论的分子的各向异性性质的信息是模糊的。因此，希望分子在溶液中定向。这对于dna双链来说是可能的，把它的溶液放在速度梯度为10^3 cm S^-1/cm数量级的流动中。例如，WADA和Kozawa(J.Polmer Sci.，A2,853(1964))在放置在两个同轴圆柱体之间的缝隙中的溶液流动中产生了这样的速度梯度，其中一个圆柱体被迅速旋转。他们研究了DNA在260 nm吸收的各向异性。在本研究中，类似的技术已应用于拉曼和荧光光谱。将DNA溶液放置在两个同轴圆柱体之间的间隙(1 Mm)中；外圆筒的内径为12 mm，内柱的外径为10 mm。当内圆柱体以每分钟2500转的速度旋转时，通过缝隙的液体流动会产生足够大的速度梯度，从而使DNA分子沿流动方向定向。通过从圆柱体底部平行于圆柱轴的方向将激发激光射入缝隙，研究了DNA分子拉曼散射的各向异性。在DNA溶液中加入抗癌药物阿克拉霉素A(盐酸盐)，考察了其发射光谱和拉曼光谱的各向异性。已经证实阿克拉霉素与DNA结合，其发色团平行于DNA双链的基平面，因此，新构建的仪器被证明是解释DNA-药物相互作用的几何图形的有力工具。