Department of Physics, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy.
Department of Experimental Medicine, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
Int J Mol Sci. 2021 Jan 29;22(3):1334. doi: 10.3390/ijms22031334.
The interaction of cytochrome c (cyt c) with natural and synthetic membranes is known to be a complex phenomenon, involving both protein and lipid conformational changes. In this paper, we combined infrared and fluorescence spectroscopy to study the structural transformation occurring to the lipid network of cardiolipin-containing large unilamellar vesicles (LUVs). The data, collected at increasing protein/lipid ratio, demonstrate the existence of a multi-phase process, which is characterized by: (i) the interaction of cyt c with the lipid polar heads; (ii) the lipid anchorage of the protein on the membrane surface; and (iii) a long-distance order/disorder transition of the cardiolipin acyl chains. Such effects have been quantitatively interpreted introducing specific order parameters and discussed in the frame of the models on cyt c activity reported in literature.
细胞色素 c（cyt c）与天然和合成膜的相互作用是一个复杂的现象，涉及蛋白质和脂质构象的变化。在本文中，我们结合红外和荧光光谱研究了含心磷脂的大单层囊泡（LUV）的脂质网络发生的结构转变。在增加蛋白质/脂质比的情况下收集的数据表明，存在多相过程，其特征在于：（i）cyt c 与脂质极性头部的相互作用；（ii）蛋白质在膜表面上的脂质锚定；和（iii）心磷脂酰链的长程有序/无序转变。通过引入特定的有序参数，可以对这些影响进行定量解释，并根据文献中报道的 cyt c 活性模型进行讨论。
