Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada; Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
Colloids Surf B Biointerfaces. 2019 Jun 1;178:94-102. doi: 10.1016/j.colsurfb.2019.02.050. Epub 2019 Feb 26.
Fengycin is an antimicrobial cyclic lipopeptide known to interact with microbial cell membranes. To gain insight into the role of lipids in fengycin sensitivity, lipids extracted from Alternaria solani, Fusarium sambucinum, and Pythium sulcatum were analyzed and used in the preparation of supported lipid bilayers (SLBs). Total Internal Reflection Fluorescence Microscopy (TIRFM) was used to evaluate lipid phase separation within the SLBs and changes in domain distribution with the application of fengycin. A. solani lipid extract contained the highest quantity of ergosterol while P. sulcatum contained no ergosterol. Sterol content of SLBs was strongly correlated with increases in phase separation, suggesting ergosterol may play a role in promoting ordering of the lipid phases in the bilayer. A. solani experienced the least change in domain characteristics following fengycin exposure, suggesting ergosterol may be buffering effects of the antimicrobial compound. Factors such as lipid headgroup charge and unsaturation levels may impact fengycin's effects on domain phase separation, but these effects were generally overshadowed by the role of ergosterol. In the absence of ergosterol, in the P. sulcatum bilayers, fengycin caused an increase in lipid phase ordering.
丰原菌素是一种已知与微生物细胞膜相互作用的抗菌环状脂肽。为了深入了解脂质在丰原菌素敏感性中的作用，分析了从茄病镰刀菌、匐枝根霉和蛙形环腐菌中提取的脂质，并将其用于制备支撑脂质双层（SLB）。全内反射荧光显微镜（TIRFM）用于评估 SLB 内的脂质相分离以及丰原菌素应用后域分布的变化。A. solani 脂质提取物含有最高量的麦角固醇，而 P. sulcatum 不含麦角固醇。SLB 中的固醇含量与相分离的增加呈强烈相关，表明麦角固醇可能在促进双层中脂质相的有序排列中起作用。A. solani 在丰原菌素暴露后域特征变化最小，表明麦角固醇可能缓冲了抗菌化合物的作用。脂质头部基团电荷和不饱和水平等因素可能会影响丰原菌素对域相分离的作用，但这些作用通常被麦角固醇的作用所掩盖。在没有麦角固醇的情况下，在 P. sulcatum 的双层中，丰原菌素引起脂质相有序性增加。
