外层球对零型铜蛋白电子结构的贡献
Kyle M Lancaster1, María-Eugenia Zaballa, Stephen Sproules
1California Institute of Technology, Pasadena, California 91125, United States. kml236@cornell.edu
Journal of the American Chemical Society
|May 9, 2012
概括
研究人员在蛋白质中发现了新的"零型"铜部位,挑战了生物无机法典. 这些网站缺乏硫酸盐协调,表现出独特的电子结构和电子转移特性.
科学领域:
- 生物有机化学 生物有机化学
- 生物物理学的生物物理.
- 蛋白质工程是一种蛋白质工程.
背景情况:
- 已确立的生物无机规范认为,活性位点酸盐协调对于1型铜蛋白中的快速电子转移 (ET) 是必不可少的.
- 最近的发现表明,铜ET站点可以在没有硫酸盐结合的情况下进行工程设计,称为"零型"站点.
研究的目的:
- 为了研究Pseudomonas aeruginosa azurin变种中类型零铜位点的结构和电子特性.
- 为了比较类型零站点的电子结构与野生类型 (类型1) 和类型2铜中心.
主要方法:
- 多频电子偏磁共振 (EPR),磁圆二合体 (MCD) 和核磁共振 (NMR) 光谱.
- 密度函数理论 (DFT) 和光谱面向的配置相互作用 (SORCI) 的计算.
- 量子力学/分子力学 (QM/MM) 模拟.
主要成果:
- 在Pseudomonas aeruginosa azurin变种中,零型铜中心表现出与野生型1型中心几乎相同的配体场.
- 与1型和2型蛋白相比,在类型零中心观察到增强的O-捐赠者协同性和减少的N-捐赠者协同性.
- 0型和2型站点的电子结构受到碳酸盐联体的定向和协调的强烈影响,由外部球体键调节.
结论:
- 零型铜位代表了对传统的1型位的可行替代方案,用于调节电子转移特性.
- 碳酸盐连接体的协调和定向受结合的影响,是非硫酸盐铜中心电子结构的关键决定因素.
- 这项研究扩大了对铜蛋白活性部位的理解,并为蛋白质工程提供了新的途径.
更多相关视频
06:53Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
02:46Electron Configurations
Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest energy available), Pauli exclusion principle (no two electrons can have the same set of four quantum numbers), and Hund’s rule of maximum multiplicity (whenever possible, electrons retain unpaired spins in degenerate orbitals).
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...