相关实验视频
Updated: Jul 10, 2026

11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
对α-螺旋和β-hairpin折叠动力学的理论描述
Isabella Daidone1, Marco D'Abramo, Alfredo Di Nola
1Department of Chemistry, University of Rome La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy.
Journal of the American Chemical Society
|October 20, 2005
概括
这项研究使用自由能量表面和扩散来模拟折叠动力学. 这些发现揭示了状的能量概况和非指数折叠,与阿尔法螺旋和β-hairpin的实验数据保持一致.
科学领域:
- 生物物理学的生物物理.
- 计算生物学 计算生物学
- 蛋白质动力学 蛋白质动力学
背景情况:
- 了解蛋白质折叠对于分子生物学和疾病研究至关重要.
- 精确建模折叠动力学仍然是一个重大挑战.
研究的目的:
- 为了建模折叠动力学作为一个扩散过程在一个 conformational 自由能量表面.
- 为了研究alpha-helical和beta-hairpin的折叠路径.
- 为了比较动力合在使用1D和2D自由能量表面的折叠中的相关性.
主要方法:
- 原子学分子动力学模拟以获得构造自由能量表面和扩散系数.
- 在计算的自由能景观上,模拟折作为扩散过程.
- 解决1D和2D自由能量表面的扩散方程.
主要成果:
- 临时蛋白L (α-螺旋) 和蛋白H1 (β-毛) 酸表现出类似漏斗的,几乎没有障碍的自由能量配置.
- 观察到这些的非指数折叠动力学,与实验数据相匹配.
- 该模型准确地复制了一种蛋白质GB1β-hairpin的两种状态折叠动力学,预测时间常数约为5微秒,接近实验中的6微秒.
结论:
- 的折叠可以有效地被模拟为在自由能量表面上的扩散过程.
- 状的能量格局是控制这些的折叠动力学的关键特征.
- 形状自由度之间的动力合可能在折叠过程中发挥作用,这需要进一步研究.
相关概念视频
Mechanisms of Membrane-bending
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...
Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Equation of Rotational Dynamics
Angular variables are introduced in rotational dynamics. Comparing the definitions of angular variables with the definitions of linear kinematic variables, it is seen that there is a mapping of the linear variables to the rotational ones. Linear displacement, velocity, and acceleration have their equivalents in rotational motion, which are angular displacement, angular velocity, and angular acceleration. Similar to the rotational variables, a mapping exists from Newton's second law of motion...
Angle of Twist: Problem Solving
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the torque exerted...
Stability of structures
In mechanical engineering, the stability of systems under various forces is critical for designing durable and efficient structures. One fundamental way to explore these concepts is by analyzing systems like two rods connected at a pivot point, O, with a torsional spring of spring constant k at the pivot point. This system is similar in appearance to a scissor jack used to change tires on a car. In this case, the arms of the linkage (equivalent to the rods in this system) are entirely vertical,...

