氨基酸的内部和分子间拓性质:对实验和理论结果的比较研究
R Flaig1, T Koritsanszky, B Dittrich
1Institute for Chemistry/Crystallography, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany.
Journal of the American Chemical Society
|March 28, 2002
概括
这项研究使用X射线衍射确定了六种氨基酸的电荷密度. 实验和理论的债券特性通常一致,但一些电荷密度特征显示出显著的差异.
科学领域:
- 晶体学 晶体学是指结晶学.
- 量子化学 是一个量子化学.
- 生物化学 生物化学
背景情况:
- 氨基酸是蛋白质的基本组成部分.
- 了解氨基酸中的电荷分布对于分子相互作用至关重要.
- 以前的研究已经探索了氨基酸电荷密度,但需要进一步的实验验证.
研究的目的:
- 通过实验确定六种特定氨基酸的电荷密度.
- 将实验电荷密度和推导的拓参数与理论计算进行比较.
- 调查实验和理论数据之间的一致性和差异.
主要方法:
- 高分辨率的X射线衍射实验在100K进行.
- 使用了同步辐射和电荷合装置 (CCD) 区域探测器.
- 为了进行理论比较,进行了ab initio计算.
主要成果:
- 对于L-Asn.H2O,DL-Glu.H2O,DL-Lys.HCl,DL-Pro.H2O,DL-Ser 和DL-Val.O,获得了实验性电荷密度 (rho(r).
- 实验和理论债券拓参数显示,对于化学等价债券来说,公平的协议.
- 在键关键点的电荷密度曲率和非结合电荷度的位置上观察到差异.
结论:
- 实验性电荷密度研究为氨基酸电子结构提供了宝贵的见解.
- 虽然理论方法接近实验结果,但具体特征,如电荷密度曲率需要进一步调查.
- 非结合电荷度的散射凸显了晶体和孤立分子状态之间的差异.
更多相关视频
08:22Calibration-free In Vitro Quantification of Protein Homo-oligomerization Using Commercial Instrumentation and Free, Open Source Brightness Analysis Software
Published on: July 17, 2018
10:23Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules
Published on: April 25, 2025
相关概念视频
Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Protein-protein Interfaces
Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide...
Molecular Structure and Acidity
An acid can be deprotonated to form a conjugate base or an anion. If the produced anion is more stable, then the acid is stronger. On the contrary, if the anion is unstable, then the acid is weaker. Hence, to determine the acidity of the compound, the stability of its conjugate base is studied using various factors.
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
