在乙基链中的不同侧包装应力改变了脂质膜中的KcsA的方向和结构
Eri Saki H Hayakawa1, Misuzu Ueki2, Elmukhtar Alhatmi3
1Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
Biochimica et biophysica acta. Biomembranes
|May 19, 2024
概括
脂酸链长度和不和影响膜特性和K+通道结构. 这项研究揭示了酸糖醇变异如何影响细菌膜物理和蛋白质行为.
科学领域:
- 生物物理学的生物物理.
- 膜生物学 膜生物学
- 结构生物学 结构生物学
背景情况:
- 脂质结构决定了膜特性和蛋白质相互作用.
- 细胞膜主要使用酸丁胆和酸丁乙醇胺 (PE).
- 细菌膜富含酸丁 (PG) 和PE,具有未溶解的链特性.
研究的目的:
- 研究细菌脂糖醇 (PG) 中的乙链的物理和热力学特性.
- 确定PG中的不同乙基链如何影响膜的物理化学性质.
- 检查PG变异对K+通道KcsA的结构和方向的影响.
主要方法:
- 使用的脂质体由1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG) 和1-palmitoyl-2-arachidonoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (PAPG) 组成. 这两种脂质体的组分分别是1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) 和1-palmitoyl-2-arachidonoyl-sn-glycero-3-phospho-
- 使用DPH光探头通过评估DPH旋转自由度来测量脂质包装.
- 在POPG和PAPG双层中嵌入K+通道KcsA,以研究其结构变化.
主要成果:
- 乙基链长度和PG的sn-2位置上的双键的差异显著改变了膜的物理化学特性.
- 这些脂质变化影响了嵌入式KcsA通道的结构和方向.
- 脂质包装应激是由POPG和PAPG的特定乙烯链组成调节的.
结论:
- 酸丁糖醇的链特征是细菌膜性质的关键决定因素.
- PG乙基链的变化会影响KcsA等关键蛋白质的结构状态和膜整合.
- 了解这些脂质-蛋白质相互作用对于破译细菌膜功能至关重要.
相关概念视频
Mechanisms of Membrane-bending
2.7K
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...
2.7K
Asymmetric Lipid Bilayer
7.2K
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
7.2K
Lipids as Anchors
5.6K
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 carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...
5.6K
Assembly of the Lipid Bilayer in the ER
3.1K
Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
3.1K
Membrane Fluidity
11.1K
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...
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...
11.1K
Cytoskeletal Coordination in Cell Migration
4.7K
A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker...
4.7K


