関連する実験動画

Updated: Jan 30, 2026

Measuring Protein Binding to F-actin by Co-sedimentation

Measuring Protein Binding to F-actin by Co-sedimentation

Published on: May 18, 2017

非理想的沈着速度による超弱タンパク質自己結合の測定

Sumit K Chaturvedi¹, Vatsala Sagar², Huaying Zhao¹

¹Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics , National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health , Bethesda , Maryland 20892 , United States.

Journal of the American Chemical Society

|January 23, 2019

まとめ

超弱タンパク質の自己結合を研究することは困難ですが,生物学的プロセスを理解するために不可欠です. 新しい沈殿速度法により,弱い結合相互作用の正確な測定が可能になり,自由エネルギーの変化が明らかになります.

科学分野:

バイオ物理学
タンパク質の相互作用
マクロ分子溶液

背景:

超弱い自己結合は,濃縮されたマクロ分子溶液に影響し,複雑な組立と相変化のシグナリングのような生物学的機能に影響します.
これらの弱い相互作用の研究は,高いタンパク質濃度とサンプル多分散性のために困難です.

研究の目的:

超弱タンパク質の自己結合を正確に測定するための沈着速度技術を開発し,検証する.
素早く反転する自己結合の自由エネルギーを導出する.

主な方法:

遠心場での沈殿速度を利用して,質量に依存したタンパク質の分離を行います.
コロイド水力学的相互作用と熱力学的非理想性を考慮した.
ミリモラー濃度で中型タンパク質を研究するために,ラベルフリーメソッドを適用した.

主要な成果:

鶏卵リゾジームのイオン強度依存の弱い自己結合を再現しました.
24 mMの解離常数 (K_D) を有するチキン γS-結晶の量化弱単体-二重体自己結合.
鶏のγS-結晶結合の標準的な自由エネルギー変化は約-9 kJ/molを決定した.

結論:

沈着速度の方法は,超弱で迅速に逆転するタンパク質の自己結合を研究するのに有効です.
このテクニックは,生物学的システムと眼レンズの透明性に関連した,溶液中のタンパク質の行動を支配する力についての洞察を提供します.

さらに関連する動画

Separation of Spermatogenic Cell Types Using STA-PUT Velocity Sedimentation

Separation of Spermatogenic Cell Types Using STA-PUT Velocity Sedimentation

Published on: October 9, 2013

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability

Published on: April 2, 2015

関連する概念動画

Weak Base Solutions

Weak Base Solutions

Some compounds produce hydroxide ions when dissolved by chemically reacting with water molecules. In all cases, these compounds react only partially and so are classified as weak bases. These types of compounds are also abundant in nature and important commodities in various technologies. For example, global production of the weak base ammonia is typically well over 100 metric tons annually, being widely used as an agricultural fertilizer, a raw material for chemical synthesis of other...

Ideal Solutions

Ideal Solutions

According to Raoult’s law, the partial vapor pressure of a solvent in a solution is equal or identical to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution. However, Raoult's Law is only valid for ideal solutions. For a solution to be ideal, the solvent-solute interaction must be just as strong as a solvent-solvent or solute-solute interaction. This suggests that both the solute and the solvent would use the same amount of energy to escape to the...

Weak Acid Solutions

Weak Acid Solutions

Few compounds act as strong acids. A far greater number of compounds behave as weak acids and only partially react with water, leaving a large majority of dissolved molecules in their original form and generating a relatively small amount of hydronium ions. Weak acids are commonly encountered in nature, being the substances partly responsible for the tangy taste of citrus fruits, the stinging sensation of insect bites, and the unpleasant smells associated with body odor. A familiar example of a...

Titration of a Weak Acid with a Weak Base

Titration of a Weak Acid with a Weak Base

Weak acids and bases do not undergo dissociation completely, and titrations between these two are rarely studied. When such studies are performed, say, for the titration of a weak acid with a weak base, the titration curve plots the change in pH as a function of the volume of base added. Take the titration of acetic acid with ammonia, for instance. During the titration, these two species form ammonium acetate and water, but the pH change is slow and gradual.
As a result, there is no simple...

Titration Calculations: Weak Acid - Strong Base

Titration Calculations: Weak Acid - Strong Base

Calculating pH for Titration Solutions: Weak Acid/Strong Base
For the titration of 25.00 mL of 0.100 M CH3CO2H with 0.100 M NaOH, the reaction can be represented as:

The Ideal Transformer

The Ideal Transformer

In single-phase two-winding transformers, two windings are coiled around a magnetic core characterized by cross-sectional area A and magnetic permeability μ. A phasor current i1 enters the left winding while i2 exits the right winding, establishing the fundamental working of the transformer through electromagnetic principles.
Ampere's Law forms the basis of understanding the magnetic field within the transformer. It states that the integral of the magnetic field intensity's tangential...