对金属蛋白活性位点属性的Pi相互作用调整
Sachiko Yanagisawa1, Peter B Crowley, Susan J Firbank
1Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
Journal of the American Chemical Society
|October 23, 2008
概括
研究铜金属蛋白中的pi相互作用显示,它们调节了His连接体质子,影响了氧化还原活性. 这些相互作用稳定了伪素,但有利于塑素的解离,影响了电子转移调节.
科学领域:
- 生物化学 生物化学
- 生物有机化学 生物有机化学
- 蛋白质工程是指蛋白质工程.
背景情况:
- 含铜的氧化还原金属蛋白,如伪素和塑素,对于电子转移至关重要.
- 希斯提丁 (His) 连接体在这些金属蛋白的氧化还原活性中起着关键作用.
- 从铜中心中对His连接体的质子化和解离可以调节电子转移.
研究的目的:
- 研究活点pi相互作用对铜金属蛋白中的His连接体行为的影响.
- 了解工程化pi接触如何影响 His 配体的 pKa 和氧化还原特性.
- 探索特定残留物在调节这些相互作用及其功能后果中的作用.
主要方法:
- 位点定向的突变发生引入氨酸 (Phe) 或氨酸 (Trp) 残留物,形成pi接触物.
- 用光谱和电化学技术分析His联体质子化状态和pKa值.
- 酶动力学和电子自我交换测量以评估功能影响.
主要成果:
- 引入的芳香残留物和His配体之间的工程pi接触在伪素和塑素变体中得到证实.
- 皮相互作用对他的配体pKa产生了相反的效应:稳定了伪氨酸中的协调形式,并有利于塑素中的质子化/解离.
- 突变显著影响了伪素的降解潜力和电子自我交换,而Met16Phe影响了酸还原酶协会.
结论:
- 活点pi相互作用是调节His连接体质子和铜金属蛋白氧化还原活性的一个重要因素.
- 在pi-contact几何学中微妙的差异导致不同蛋白质家族的不同功能结果.
- 由第二协调球相互作用影响的His连接体质子状态,作为电子转移的[H+]驱动开关.
更多相关视频
14:44Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
06:50Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
相关概念视频
Ligand Binding Sites
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
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...
Conserved Binding Sites
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function.
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
