结构上的小变化,灵活性上的大变化.
Nikolay G Vassilev1, Ivo C Ivanov2
1Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. Bl. 9, 1113 Sofia, Bulgaria.
Molecules (Basel, Switzerland)
|December 23, 2023
概括
使用动态核磁共振 (NMR) 和密度函数理论 (DFT) 调查胺和胺键的流动性揭示了由于电子移位而导致更高的胺障碍. 这影响了分子机器的设计.
科学领域:
- 有机化学 有机化学
- 计算化学计算化学
- 频谱学是一种光谱学.
背景情况:
- 胺基键旋转障碍对于理解键和设计分子机器至关重要.
- 之前的研究利用量子计算和NMR来建模键特性.
- 氨基酸和酶氨酸键的流动性是分子结构动态的关键.
研究的目的:
- 为了研究特定的尿素衍生物中的胺和胺键的旋转屏障能量.
- 用理论计算阐明旋转屏障中观察到的差异的电子起源.
- 将这些发现与结构相似的烯胺化合物进行比较.
主要方法:
- 用先进的动态核磁共振 (NMR) 实验来研究键的流动性.
- 密度函数理论 (DFT) 计算用于理论评估能量障碍.
- 对两个相关化合物的实验和计算数据进行比较.
主要成果:
- 该研究发现,在主要化合物中,围绕胺基组 (16.4 kcal/mol) 的旋转受到限制,围绕酶氨基组 (18.6 kcal/mol) 的屏障更高.
- 一种结构相似的化合物显示,胺 (12.4 kcal/mol) 和酶胺 (11.7 kcal/mol) 组的障碍较低.
- DFT计算表明,单对电子的增强移位到抗键轨道稳定了酶胺基本状态,增加了其旋转屏障.
结论:
- 与研究中的尿素衍生物中的胺基键相比,酶胺键表现出明显更高的旋转屏障.
- 电子移位是导致胺屏障升高的主要原因.
- 这些发现有助于对胺和胺键动态的基本理解,并对分子设计产生影响.
相关概念视频
Adaptability of Cytoskeletal Filaments
3.7K
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
3.7K
Mechanisms of Membrane-bending
2.7K
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
2.7K
Membrane Fluidity
152.5K
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.
152.5K
Changes in the Appendicular Skeleton with Age
2.0K
The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
2.0K
Bending of Members Made of Several Materials
154
In analyzing a structural member composed of two different materials with identical cross-sectional areas, it is crucial to understand how their distinct elastic properties affect the member's response under load. The analysis involves assessing stress and strain distributions using the transformed section concept, which accounts for variations in material properties.
Hooke's Law determines stress in each material, stating that stress is proportional to strain but varies due to each...
Hooke's Law determines stress in each material, stating that stress is proportional to strain but varies due to each...
154
Neuroplasticity
367
Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability.
367


