Inner-sphere complexes of divalent cations with single-stranded poly(rA) and poly(rU).
Inner-sphere complexes of divalent cations with single-stranded poly(rA) and poly(rU).
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二价阳离子与单链聚（rA）和聚（rU）的内球复合物。
DOI：
10.1002/bip.20082
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Kankia,BesikI
中科院分区：
文献类型：
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作者：
Kankia,BesikI
A combination of ultrasound velocimetry, density, and UV spectroscopy has been employed to study the hydration effects of binding of Mn2+and alkaline‐earth cations to poly(rA) and poly(rU) single strands. The hydration effects, obtained from volume and compressibility measurements, are positive due to overlapping the hydration shells of interacting molecules and consequently releasing the water molecules to bulk state. The volume effects of the binding to poly(rA), calculated per mole of cations, range from 30.6 to 40.6 cm3mol‐1and the compressibility effects range from 59.2 × 10‐4to 73.6 × 10‐4cm3mol‐1bar‐1. The volume and compressibility effects for poly(rU) are ∼17 cm3mol‐1and ∼ 50 × 10‐4cm3mol‐1bar‐1, respectively. The comparative analysis of the dehydration effects suggests that the divalent cations bind to the polynucleotides in inner‐sphere manner. In the case of poly(rU) the dehydration effects correspond to two direct coordination, probably between adjacent phosphate groups. The optical study did not reveal any effects of cation on the secondary structure or aggregation of poly(rU). In the case of single‐helical poly(rA) binding is more specific: dehydration effects correspond to three to five direct contacts and must involve atomic groups of adenines, and the divalent cations stabilize and aggregate the polynucleotide. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
