Montrel' M M, Shabarchina L I, Pletneva T V, Ershov Iu A
Biofizika. 1993 Jul-Aug;38(4):636-43.
Infrared spectra of some unoriented films of DNA contained CrCl3, K2Cr2O7 and Cr2(SO4)3 have been obtained at relative humidities (r.h.) 0 to 93%. Chromium cations were shown to interact with phosphoric groups of DNA molecules. Cr2(SO4)3 or K2Cr2O7 content exceeds 0.1 Cr/P, the sugar-phosphate backbone of the double helix becomes irregular and nucleic bases unstacked, i.e. denaturation of DNA occurs. A very small amount of the salt, less than 0.01 Cr/P contained in DNA films prevents the conformational transition of the double helix from the B to A form induced by r.h. decreasing. The efficiency of the chromium salts in preventing the transition falls in the row: Cr2(SO4)3 > K2Cr2O7-CrCl3.
已获得一些含有CrCl3、K2Cr2O7和Cr2(SO4)3的DNA非取向膜在相对湿度0至93%时的红外光谱。结果表明，铬阳离子与DNA分子的磷酸基团相互作用。当Cr2(SO4)3或K2Cr2O7含量超过0.1 Cr/P时，双螺旋的糖磷酸骨架变得不规则，核酸碱基堆积被破坏，即发生了DNA变性。DNA膜中少量的盐（小于0.01 Cr/P）可防止因相对湿度降低而诱导的双螺旋从B型向A型的构象转变。铬盐防止转变的效率顺序为：Cr2(SO4)3 > K2Cr2O7-CrCl3。
