West Jonathan D, Zhu Yujie, Saem Sokunthearath, Moran-Mirabal Jose, Hitchcock Adam P
Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4M1, Canada.
J Phys Chem B. 2017 May 4;121(17):4492-4501. doi: 10.1021/acs.jpcb.7b02646. Epub 2017 Apr 19.
The C 1s, O 1s, and N 1s X-ray absorption spectra of three lipid species, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and 1,2-dioleoyl-3-trimethylammonium-propane (chloride salt) (DOTAP), have been recorded using transmission detection in a scanning transmission X-ray microscope. The spectra are presented on an absolute intensity scale (i.e., optical density per nm) to allow their use as reference standards for spectromicroscopic analysis of supported lipid bilayers. Examples of C 1s based spectromicroscopic mapping of saturated and unsaturated domains in dry lipid bilayers of DOPC and DSPC at several compositions are presented. The results are compared with fluorescence microscopy of the same area. Challenges for extending this work to studies of wet lipid bilayers interacting with antimicrobial peptides are discussed.
利用扫描透射X射线显微镜中的透射检测，记录了三种脂质分子1,2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）、1,2-二硬脂酰基-sn-甘油-3-磷酸胆碱（DSPC）和1,2-二油酰基-3-三甲基铵丙烷（氯盐）（DOTAP）的C 1s、O 1s和N 1s X射线吸收光谱。光谱以绝对强度标度（即每纳米的光密度）呈现，以便用作支持脂质双层光谱显微镜分析的参考标准。给出了在几种组成下，基于C 1s的DOPC和DSPC干脂质双层中饱和域和不饱和域的光谱显微镜映射示例。将结果与同一区域的荧光显微镜观察结果进行了比较。讨论了将这项工作扩展到研究与抗菌肽相互作用的湿脂质双层的挑战。
