School of Physics, University of Exeter, Exeter, United Kingdom.
Biophys J. 2011 Oct 19;101(8):1921-9. doi: 10.1016/j.bpj.2011.08.053.
We investigate the effect of oxidative stress on red blood cell membrane mechanical properties in vitro using detailed analysis of the membrane thermal fluctuation spectrum. Two different oxidants, the cytosol-soluble hydrogen peroxide and the membrane-soluble cumene hydroperoxide, are used, and their effects on the membrane bending elastic modulus, surface tension, strength of confinement due to the membrane skeleton, and 2D shear elastic modulus are measured. We find that both oxidants alter significantly the membrane elastic properties, but their effects differ qualitatively and quantitatively. While hydrogen peroxide mainly affects the elasticity of the membrane protein skeleton (increasing the membrane shear modulus), cumene hydroperoxide has an impact on both membrane skeleton and lipid bilayer mechanical properties, as can be seen from the increased values of the shear and bending elastic moduli. The biologically important implication of these results is that the effects of oxidative stress on the biophysical properties, and hence the physiological functions, of the cell membrane depend on the nature of the oxidative agent. Thermal fluctuation spectroscopy provides a means of characterizing these different effects, potentially in a clinical milieu.
我们使用膜热波动谱的详细分析研究了体外氧化应激对红细胞膜力学性能的影响。使用了两种不同的氧化剂，即细胞质可溶的过氧化氢和膜可溶的过氧化枯烯，并测量了它们对膜弯曲弹性模量、表面张力、膜骨架约束强度和二维剪切弹性模量的影响。我们发现，两种氧化剂都显著改变了膜的弹性性质，但它们的影响在定性和定量上有所不同。虽然过氧化氢主要影响膜蛋白骨架的弹性（增加膜的剪切模量），但过氧化枯烯对膜骨架和脂质双层的机械性能都有影响，这可以从剪切和弯曲弹性模量的增加看出。这些结果在生物学上的重要意义是，氧化应激对细胞膜生物物理特性的影响，进而对其生理功能的影响，取决于氧化剂的性质。热波动光谱为在临床环境中描述这些不同的影响提供了一种手段。
