对具有反平行和平行β片结构的氨酸三酸的结构分析,与在Samia cynthia ricini丝蛋白纤维中混合β片结构的分析有关,使用固态NMR光谱学分析
Tetsuo Asakura1, Michi Okonogi, Yasumoto Nakazawa
1Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan. asakura@cc.tuat.ac.jp
Journal of the American Chemical Society
|May 4, 2006
概括
固态核磁共振 (NMR) 可以区分蛋白质纤维结构. 在平行β片中,更长的旋转放松时间 (T1) 有助于与反平行结构的差异化.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 材料科学 材料科学 材料科学
背景情况:
- 天然蛋白质纤维具有复杂的结构安排,包括平行和反平行β片结构.
- 固态核磁共振 (NMR) 是一种强大的技术,用于分析不溶性生物材料的结构,如蛋白质纤维.
研究的目的:
- 用固态NMR来描述和区分蛋白质纤维中的平行和反平行β片结构.
- 为了确定特定的NMR参数,可以作为这些独特的结构图案的标记.
主要方法:
- (13) 在100%平行和100%反平行β片结构的氨酸三样本上进行了C固态NMR实验.
- 通过选择性同位素标记 ([3-(13) C]Ala) 和带有不同混合时间的射频驱动回 (RFDR) 实验来实现共振分配.
- 分析的重点是 (13) C 化学转移和 (13) C 旋转晶格放松时间 (T(1)).
主要成果:
- 所有三的 (13) C 共振均成功分配,每单元细胞分别识别出两个不同的分子.
- 在平行和反平行β片结构之间观察到 (13)C化学转移和T(1) 值的显著差异.
- 与反平行结构相比,平行β-sheet结构的T(1) 值大约是反平行结构的三倍,这归因于键网络的差异.
结论:
- 在T(1) 值的实质差异提供了一个可靠的方法来区分平行和反平行β-sheet结构.
- 这些NMR参数差异可用于分析天然丝蛋白纤维的复杂光谱,有助于分配β-sheet共振.
相关概念视频
Protein Organization
Overview
Protein Folding
Overview
Protein and Protein Structure
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
A protein's shape is critical to its function. For example, an enzyme can...
Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Structure of Amines
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...


