Luchini Alessandra, Corucci Giacomo, Chaithanya Batchu Krishna, Laux Valerie, Haertlein Michael, Cristiglio Viviana, Fragneto Giovanna
Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
Institut Laue Langevin, Grenoble, France.
Front Chem. 2021 Mar 18;9:628186. doi: 10.3389/fchem.2021.628186. eCollection 2021.
Eukaryotic and prokaryotic cell membranes are difficult to characterize directly with biophysical methods. Membrane model systems, that include fewer molecular species, are therefore often used to reproduce their fundamental chemical and physical properties. In this context, natural lipid mixtures directly extracted from cells are a valuable resource to produce advanced models of biological membranes for biophysical investigations and for the development of drug testing platforms. In this study we focused on single phospholipid classes, i.e. phosphatidylcholine (PC) and phosphatidylglycerol (PG) lipids. These lipids were characterized by a different distribution of their respective acyl chain lengths and number of unsaturations. We produced both hydrogenous and deuterated lipid mixtures. Neutron diffraction experiments at different relative humidities were performed to characterize multilayers from these lipids and investigate the impact of the acyl chain composition on the structural organization. The novelty of this work resides in the use of natural extracts with a single class head-group and a mixture of chain compositions coming from yeast or bacterial cells. The characterization of the PC and PG multilayers showed that, as a consequence of the heterogeneity of their acyl chain composition, different lamellar phases are formed.
真核细胞和原核细胞膜很难用生物物理方法直接进行表征。因此，通常使用包含较少分子种类的膜模型系统来重现它们的基本化学和物理性质。在此背景下，直接从细胞中提取的天然脂质混合物是制备用于生物物理研究和药物测试平台开发的先进生物膜模型的宝贵资源。在本研究中，我们聚焦于单一磷脂类别，即磷脂酰胆碱（PC）和磷脂酰甘油（PG）脂质。这些脂质的特征在于其各自酰基链长度和不饱和度数量的不同分布。我们制备了含氢和含氘的脂质混合物。在不同相对湿度下进行中子衍射实验，以表征这些脂质的多层结构，并研究酰基链组成对结构组织的影响。这项工作的新颖之处在于使用了具有单一类别头部基团以及来自酵母或细菌细胞的链组成混合物的天然提取物。PC和PG多层结构的表征表明，由于其酰基链组成的异质性，可以形成不同的层状相。
