Buckin V A, Kankiya B I, Kazaryan R L
Institute of Biological Physics, Academy of Sciences of the U.S.S.R., Moscow Region.
Biophys Chem. 1989 Nov;34(3):211-23. doi: 10.1016/0301-4622(89)80060-2.
The values of the concentration increments of the ultrasound velocity and their temperature slopes, apparent molar volumes, apparent molar expansibilities, apparent molar adiabatic compressibilities and their temperature gradients for 12 nucleosides and their analogs, as well as for ribose and deoxyribose, have been obtained using precision measurements of ultrasound velocity and density. The following hydration parameters for the atomic groups of the nucleosides, reflecting the state of water in the hydration shells of these groups, have been analyzed: (1) the contribution of ribose to the values of the concentration increment of ultrasound velocity A, the apparent molar volumes phi v and apparent molar adiabatic compressibilities phi ks of nucleosides; (2) contributions of the CH3, NH2 and O = ... -H groups of nucleic bases to the A, phi v and phi ks values of nucleosides and free nucleic bases; (3) contributions of the 2'-OH group of ribose to the values of A, phi v and phi ks nucleosides; (4) changes in the A values of nucleosides and free nucleic bases upon their protonation and deprotonation. Data have been obtained on the mutual influence of the atomic groups of nucleosides on their hydration. It is shown that the GC pairs of free deoxynucleosides undergo hydration more vigorously than the AT pairs, which contrasts with the relation of the degree of hydration of the GC and AT pairs of the double helix.
通过对超声速度和密度的精确测量，已获得12种核苷及其类似物以及核糖和脱氧核糖的超声速度浓度增量及其温度斜率、表观摩尔体积、表观摩尔膨胀系数、表观摩尔绝热压缩系数及其温度梯度的值。分析了反映核苷原子团水化壳层中水状态的下列水化参数：(1)核糖对核苷超声速度浓度增量A、表观摩尔体积φv和表观摩尔绝热压缩系数φks值的贡献；(2)核酸碱基的CH3、NH2和O=...-H基团对核苷和游离核酸碱基的A、φv和φks值的贡献；(3)核糖的2'-OH基团对核苷的A、φv和φks值的贡献；(4)核苷和游离核酸碱基质子化和去质子化时A值的变化。已获得关于核苷原子团相互间水化影响的数据。结果表明，游离脱氧核苷的GC碱基对比AT碱基对水化更剧烈，这与双螺旋中GC和AT碱基对的水化程度关系相反。
