完全に最適化されたアルファ・ヘリックスと3・10・ヘリクスを拡張ベータ・ストランドで比較. ONIOMの密度関数理論の研究である
Robert Wieczorek1, J J Dannenberg
1Department of Chemistry, City University of New York-Hunter College and the Graduate School, 695 Park Avenue, New York, New York 10021, USA.
Journal of the American Chemical Society
|October 28, 2004
まとめ
私たちは,ポリアラニンの螺旋状構造を研究しました. アルファヘリクスはペプチドのサイズが大きくなるにつれて3(10) ヘリクスよりも安定し,タンパク質の折りたたみにおけるサイズ依存の安定性を示します.
科学分野:
- 計算化学はコンピュータ化学である.
- バイオフィジックス 生物物理学
- 構造生物学 構造生物学とは
背景:
- ベータ鎖,アルファヘリックス,および3(10) ヘリックスを含むタンパク質の二次構造は,タンパク質の折り畳みと機能に不可欠です.
- ペプチド内のこれらのモチーフのエネルギーと構造の安定性を理解することは,タンパク質の振る舞いを予測するために不可欠です.
研究 の 目的:
- カップされたポリアラーニンにおけるβ鎖,アルファヘリックス,および3(10) ヘリクスの構造およびエネルギー特性を比較する.
- ペプチドサイズ (N=2-18) が螺旋的な安定性と形状に及ぼす影響を調査する.
主な方法:
- 完全な最適化のために混合密度関数理論 (DFT) とオースティンモデル1 (AM1) の計算を活用しました.
- 相対エネルギー,螺旋的な張力,二極分数,水素結合の長さを分析した.
主要な成果:
- 螺旋構造において,特にアルファヘリックスにおいて顕著な,非対対の添加的協力性を観察した.
- 3(10) -ヘリクスは,追加の水素結合により,より小さなポリアラーニンに対してより安定していることが判明しました.
- アルファヘリクスは,ポリアラニンのサイズが大きくなるにつれて比較的安定性が高いことが示されました.
結論:
- ペプチドのサイズは,異なる螺旋構造の相対的な安定性に大きく影響します.
- 3(10) ヘリックスからアルファヘリックスへの安定性の移行は,ペプチド構成におけるエネルギー要因の複雑な相互作用を強調しています.
- 計算モデリングは,タンパク質の二次構造形成を制御する基本的な原理に関する貴重な洞察を提供します.
関連する概念動画
Protein Organization
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...
Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
Globular and Fibrous Proteins
Many proteins can be classified into two distinct subtypes - globular or fibrous. These two types differ in their shapes and solubilities.
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Molecular Geometry and Dipole Moments
The VSEPR theory can be used to determine the electron pair geometries and molecular structures as follows:
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.


