関連する実験動画
Updated: Jul 10, 2026

08:51
Monitoring Protein Adsorption with Solid-state Nanopores
Published on: December 2, 2011
固体状態のNMRからカチオン膜ペプチドによる脂質膜へのリン酸媒介アルギニンの挿入と孔形成
Ming Tang1, Alan J Waring, Mei Hong
1Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Journal of the American Chemical Society
|August 21, 2007
まとめ
充電された残留物は,グアニジニウム・リン酸相互作用によって脂質二重層に挿入され,トロイド状の毛穴を形成する. 抗微生物ペプチドで観察されたこのメカニズムは,アニオンのリン酸塩を膜核に引っ張るカチオンのアルギニン残基を伴う.
科学分野:
- バイオフィジックス 生物物理学
- 膜生物物理学 膜生物物理学
- バイオケミストリー バイオケミストリー
背景:
- 水害性脂質二重層の有電荷アミノ酸残基は,エネルギー的に不利である.
- カチオン膜ペプチドとタンパク質ドメインは,しばしば2層の脂質に電荷された残基を挿入します.
- 脂質二重層の間で充電された残留物の転移のメカニズムは不明である.
研究 の 目的:
- 脂質二重層にわたって充電された残留物の転移のメカニズムを解明する.
- アルギニンに富んだペプチドと脂質膜の相互作用を調査する.
- トロイド状の毛穴の形成の直接的な証拠を提供するために.
主な方法:
- 固体核磁気共鳴 (NMR) スペクトロスコーピーは, (13) C-(31) P 距離を測定するために使用されます.
- ペプチドの形状を確認するためのトルション角度測定.
- ゲル相 (1) Hスピン拡散により,膜内のペプチドの位置が判定される.
主要な成果:
- 脂質膜内のペプチドの複数のアルギニン残留物に対する短い (13) C-(31) P 距離 (4.0-8.0 A) を測定した.
- アルギニンとリン酸群の間のN-H...O-P水素結合形成の証拠. アルギニンとリン酸群の間のN-H...O-P水素結合形成の証拠. アルギニンとリン酸群の間のアルギニンとリン酸群の形成の証拠. アルギニンとリン酸群の形成の証拠. アルギニンとリン酸群の形成の証拠. アルギニンとリン酸群の形成の証拠. アルギニンとリン酸群の形成の証拠.
- ペプチドのトランスメブランベータ-ヘアピン構成の確認.
- 脂質リン酸塩群が水嫌膜核に埋め込まれているトロイド状孔形成の直接的な証拠.
結論:
- グアニジニウム・フォスファートの複合化により,カチオニンアルギニンの残基が,水嫌膜核に挿入される.
- グアニジニウムイオンのこのリン酸媒介の転位は,タロイド孔形成の重要なメカニズムです.
- このメカニズムは,他のアルギニンに富んだ抗微生物ペプチドやカチオン膜タンパク質にも関連していることが示唆されています.
関連する概念動画
Membrane Fluidity
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.Fatty acids tails of phospholipids can be either saturated or...
Membrane Fluidity
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Lipids as Anchors
In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Porin Insertion in the Outer Mitochondrial Membrane
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Mechanisms of Membrane Domain Formation
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Types of Membrane Protrusions
The protrusion of the cell surface is an initial step for several cellular processes, including cell migration, phagocytosis, and neurite outgrowth. These membrane protrusions are a result of cytoskeletal rearrangement. The most widely observed cell protrusions include lamellipodia, pseudopodia, filopodia, microvilli, invadopodia, and podosomes. These protrusions can be of two types — static or dynamic.
The microvilli, an example of stable protrusions, are finger-like projections with a...
The microvilli, an example of stable protrusions, are finger-like projections with a...

