通过量子力学/分子力学和激活-菌株模型揭示SalL化酶反应机制和选择性
Néstor Gutiérrez-Sánchez1, Fernando Mendizábal2, Sebastián Miranda-Rojas1,3
1Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andres Bello, República 275, 8370146, Santiago, Chile.
ChemPlusChem
|August 19, 2025
概括
这项研究揭示了SalL酶.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 计算化学的计算化学
背景情况:
- SalL是一种酶酶,可催化S-adenosylmethionine (SAM) 转化为5'-chloro-5'-deoxyadenosine的过程.
- 了解化反应机制对于酶工程和药物发现至关重要.
研究的目的:
- 为了阐明SalL化酶的反应机制.
- 在化过程中识别酶活性部内的关键相互作用.
- 为了对研究酶化过程的计算方法进行基准测试.
主要方法:
- 分子动力学 (MD) 模拟.分子动力学 (MD) 模拟.
- 量子力学/分子力学 (QM/MM) 的计算.
- 14个密度函数的基准测试,包括TPSSh (BJ).
- 内在反应坐标 (IRC) 方法,反应力分析和激活应变模型 (ASM) 与能量分解分析 (EDA).
主要成果:
- 该TPSSh(BJ) 函数产生了与实验值最接近的能量屏障.
- 一个关键的相互作用模型显示屏障高度为20.1 kcal/mol,与实验中的19.9 kcal/mol非常接近.
- 化物与Gly131和Tyr130骨干胺基的相互作用被确定为关键.
- 素结合的过度稳定增加了屏障,解释了化物活动的缺乏.
结论:
- 这项研究为SalL酶的化机制提供了详细的化学见解.
- 轨道相互作用能量是化过程中的主要稳定因素.
- 酶活性部位相互作用显著影响催化活性和基质特异性.
相关概念视频
02:25SN1 Reaction: Mechanism
12.3K
Kinetic studies of ionization of a tertiary halide in a protic solvent suggest that only the substrate participates in the rate-determining step (slow step). The nucleophile is involved only after the slowest step. The SN1 reaction takes place in a multiple-step mechanism.
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
12.3K
02:14SN2 Reaction: Kinetics
8.8K
Kinetic Studies and Significance
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
8.8K
02:27SN2 Reaction: Mechanism
14.8K
The kinetic studies of SN2 reactions suggest an essential feature of its mechanism: it is a single-step process without intermediates. Here, both the nucleophile and the substrate participate in the rate-determining step.
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
14.8K
01:15Enolate Mechanism Conventions
2.3K
When a carbonyl compound is treated with a strong base, the α position gets deprotonated to give a resonance-stabilized intermediate called an enolate. Enolates are ambident nucleophiles because they possess two nucleophilic sites that can attack an electrophile owing to the delocalization of the negative charge between the α carbon and oxygen atoms. When the oxygen atom attacks an electrophile, it is called O-attack, whereas electrophilic attack via the α carbon is known as...
2.3K
02:34Nucleophilic Substitution Reactions
17.0K
Historical perspective
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
17.0K
02:46E1 Reaction: Kinetics and Mechanism
15.8K
Here, in contrast to the E2 reaction mechanism, we delve into the aspects of the E1 reaction mechanism, which has two steps: rate-limiting loss of the leaving group and abstraction of the beta hydrogen by a weak base. Typically, the experimental proof for the E1 mechanism is via kinetic studies or isotope studies. While the former demonstrates the first-order kinetics—the dependence of the reaction solely on substrate concentration—the latter proves the abstraction of hydrogen only...
15.8K