伴随核酸间反应的水合变化:体积特征
Feixue Han1, Tigran V Chalikian
1Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 19 Russell Street, Toronto, Ontario M5S 2S2, Canada.
Journal of the American Chemical Society
|June 12, 2003
概括
乙与DNA和RNA等核酸结构的结合导致体积和可压缩性变化. 这些发现凸显了水合在药物与核酸相互作用中的关键作用.
科学领域:
- 生物物理化学 生物物理化学
- 分子生物学分子生物学
- 药物发现 药物发现 药物发现
背景情况:
- 了解药物核酸相互作用对于开发新疗法至关重要.
- 乙是一种众所周知的介质剂,用于研究DNA和RNA结构.
- 像体积和可压缩性变化这样的宏观性质为分子相互作用提供了洞察力.
研究的目的:
- 要量化体积 (deltaV) 和亚基压缩性 (deltaK(S)) 在乙与各种DNA和RNA双重体和三重体结合时发生的变化.
- 以核酸结构的差异化性质来解释这些宏观变化.
- 为了估计与乙基间隔相关的水化变化的性成本.
主要方法:
- 高精度超声波速度测量和密度测量在25°C.
- 测量体积和增压压缩能力的变化.
- 基于水化模型的宏观性质的定量解释.
主要成果:
- 乙结合到poly (rA) -poly (rU),poly (dAdT) -poly (dAdT),poly (dGdC) -poly (dGdC),poly (dIdC) -poly (dIdC) 双重体和poly (rU) -poly (rA) -poly (rU) 三重体导致负的deltaV和deltaK (S).
- 这些变化在定量上与无体和有体结合的核酸结构的差异性水合有关.
- 估计了核酸和乙之间因间诱导的水合变化的性成本.
结论:
- 补水在调节药物与DNA结合的能量方面发挥着至关重要的作用.
- 对核酸识别能量的准确分析和预测需要仔细考虑水化效应.
- 该研究为通过生物物理测量了解药物与核酸相互作用提供了一个框架.
相关概念视频
Molecular Shapes
Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.Two regions of electron density in a diatomic...
Atomic Nuclei: Nuclear Spin
All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although protons and neutrons in nuclei may have higher half-integer spins owing to energetic factors.
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
Nuclear Overhauser Enhancement (NOE)
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...
Atomic Nuclei: Types of Nuclear Relaxation
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...


