Sen A, Maiti M
Biophysical Chemistry Laboratory, Indian Institute of Chemical Biology.
Biochem Pharmacol. 1994 Nov 29;48(11):2097-102. doi: 10.1016/0006-2952(94)90510-x.
The interaction of sanguinarine iminium form (structure I) and sanguinarine alkanolamine form (structure II) with calf thymus DNA has been studied in buffer of pH 5.2 and pH 10.5, respectively, where the physicochemical properties of DNA remain unchanged. The binding of sanguinarine iminium form to DNA is characterized by hypochromism and bathochromism in the absorption band, quenching of fluorescence intensity, increase in fluorescence polarization anisotropy, increase in positive and negative ellipticity of DNA, sign and magnitude of the thermodynamic parameters and increase in contour length of sonicated rodlike duplex DNA indicating that it binds to DNA by a mechanism of intercalation. In contrast, sanguinarine alkanolamine form does not show (i) any significant change in fluorescence polarization anisotropy, (ii) alteration of B form structure of DNA and (iii) increase in contour length of DNA indicating that it does not bind to DNA. But at a very high concentration of DNA, the alkanolamine form is influenced to form an iminium-DNA complex.
分别在pH 5.2和pH 10.5的缓冲液中研究了血根碱亚胺形式（结构I）和血根碱链烷醇胺形式（结构II）与小牛胸腺DNA的相互作用，在这些缓冲液中DNA的物理化学性质保持不变。血根碱亚胺形式与DNA的结合表现为吸收带中的减色和红移、荧光强度猝灭、荧光偏振各向异性增加、DNA正负椭圆率增加、热力学参数的符号和大小以及超声处理的棒状双链DNA轮廓长度增加，这表明它通过嵌入机制与DNA结合。相比之下，血根碱链烷醇胺形式未显示：（i）荧光偏振各向异性有任何显著变化；（ii）DNA的B型结构改变；（iii）DNA轮廓长度增加，这表明它不与DNA结合。但在非常高浓度的DNA条件下，链烷醇胺形式会受到影响而形成亚胺-DNA复合物。
