当前位置: X-MOL 学术BBA Biomembr. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Nanomechanical characterization of single phospholipid bilayer in ripple phase with PF-QNM AFM.
Biochimica et Biophysica Acta (BBA) - Biomembranes ( IF 2.8 ) Pub Date : 2020-05-11 , DOI: 10.1016/j.bbamem.2020.183347
M Majewska 1 , D Mrdenovic 2 , I S Pieta 1 , R Nowakowski 1 , P Pieta 1
Affiliation  

Topography and nanomechanical properties of the supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) single bilayer in the ripple phase were investigated by atomic force microscopy with the use of PeakForce Quantitative Nanomechanical Mapping (PF-QNM) mode under liquid conditions. The DMPC single bilayer was deposited on the mica surface by Langmuir-Blodgett and Langmuir-Schaefer techniques combined. Next, the sample was stored overnight at 4 °C under buffer solution (pH = 7.6) in the presence of tris(hydroxymethyl)aminomethane, (Tris), and then, AFM imaging was performed at 21 °C using the same buffer. The AFM topography images revealed the presence of a periodic structure with an average wavelength of 96.0 ± 7.8 nm and an average amplitude of 0.97 ± 0.03 nm. This macro-ripple structure was asymmetric and formed by long ripples composed of two strips of different heights. The changes in topography were accompanied by local changes in the Young's modulus, which indicate that the nanomechanical properties of the bilayer are not evenly distributed, namely, the higher stripes are characterized by a lower Young's modulus than that calculated for lower stripes of the ripples. This indicates that the ripple phase is composed of phospholipid molecules of periodically changed orientation and conformation characteristic for fluid-like and gel-like state of DMPC.

中文翻译:

PF-QNM AFM在波纹相中单磷脂双层的纳米力学表征。

使用PeakForce定量纳米力学映射(PF-QNM)模式,通过原子力显微镜研究了在波纹相中支持的1,2-二肉豆蔻酰基-sn-甘油-3-磷酸胆碱(DMPC)单双层的形貌和纳米力学性能。液体条件。通过Langmuir-Blodgett和Langmuir-Schaefer技术的结合,将DMPC单双层膜沉积在云母表面。接下来,将样品在三(羟甲基)氨基甲烷(Tris)存在下于4°C的缓冲溶液(pH = 7.6)下保存过夜,然后,使用相同的缓冲液于21°C进行AFM成像。AFM形貌图显示存在周期性结构,其平均波长为96.0±7.8 nm,平均幅度为0.97±0.03 nm。这种宏观的波纹结构是不对称的,由两条不同高度的条组成的长波纹形成。形貌的变化伴随着杨氏模量的局部变化,这表明双层的纳米力学性能不是均匀分布的,即,较高的条纹的特征在于其杨氏模量低于为波纹的较低条纹所计算出的杨氏模量。这表明波纹相由周期性变化的方向和构象特征的磷脂分子组成,用于DMPC的流体状和凝胶状状态。较高的条纹的特征在于其杨氏模量比针对波纹的较低条纹的计算出的杨氏模量低。这表明波纹相由具有周期性变化的取向和构象特征的磷脂分子组成,用于DMPC的流体状和凝胶状状态。较高的条纹的特征在于其杨氏模量比针对波纹的较低条纹的计算出的杨氏模量低。这表明波纹相由具有周期性变化的定向和构象特征的磷脂分子组成,用于DMPC的流体状和凝胶状状态。
更新日期:2020-05-11
down
wechat
bug