人类脱酶中活性位点与远位突变的结构和催化后果:从分子动力学模拟的见解
Soumyajit Karmakar1, Biman Giri1, Sabyashachi Mishra1
1Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India. mishra@chem.iitkgp.ac.in.
Physical chemistry chemical physics : PCCP
|February 24, 2026
概括
人类铁二氧化酶 (hIYD) 的突变通过破坏甲状腺激素合成,导致先天性甲状腺功能低下症. 计算分析揭示了特定的hIYD突变如何导致结构和能量缺陷,影响酶功能和疾病发病.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 先天性甲状腺功能低下症 (CH) 是一种可能由甲状腺激素合成中的遗传缺陷引起的疾病.
- 人类铁二氧化酶 (hIYD) 酶的突变是已知的CH的原因.
- hIYD对于甲状腺激素的合成至关重要,它催化了酸铁素 (I-Tyr) 的脱氧化.
研究的目的:
- 通过计算方式调查与先天性甲状腺功能低下相关的已知hIYD突变 (R101W,F105-I106L,I116T) 的结构和能量后果.
- 阐明这些突变损害hIYD功能并导致甲状腺激素缺乏的分子机制.
- 了解突变位置,结构影响和临床表现之间的关系,包括延迟发病.
主要方法:
- 使用分子建模和蛋白质折叠分析的计算研究 (Wako-Saitô-Muñoz-Eaton模型).
- 分析结构扭曲,二元化接口包装和flavin和I-Tyr的结合能.
- 评估溶剂可访问表面积的变化,范德瓦尔斯包装和侧链灵活性.
主要成果:
- 与R101W相比,F105-I106L突变导致更显著的结构扭曲和较弱的二元化接口包装.
- 无论是R101W和F105-I106L突变,由于失去关键的键,都会降低flavin和I-Tyr的结合能量.
- 尽管I116T突变离活性部位偏远,但它改变了蛋白质结构和动态,可能通过远程效应加强基质结合,并解释了延迟的临床发病.
- 突变改变了蛋白质折叠路径,并可能破坏hIYD活动所需的电子转移.
结论:
- hIYD突变导致结构,能量和催化缺陷,损害甲状腺激素的合成,导致先天性甲状腺功能低下症.
- 突变的特定影响,包括它们的位置和对蛋白质动态的影响,与疾病的严重程度和发病程度相关.
- 计算方法对于了解遗传疾病的分子基础和指导治疗策略非常有价值.
相关概念视频
Ligand Binding and Linkage
5.7K
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...
5.7K
Allosteric Proteins-ATCase
6.7K
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...
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...
6.7K
Introduction to Mechanisms of Enzyme Catalysis
11.0K
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...
11.0K
ortho–para-Directing Deactivators: Halogens
7.0K
Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...
7.0K


