Extended Data Fig. 5: Extraction of lipids from the ROS membrane, identification of phosphatidylethanolamines and formation of N-ret-PE under controlled illumination conditions.
From: Capturing a rhodopsin receptor signalling cascade across a native membrane
a, Analysis of lipids through tandem MS in the negative ion mode and assignment using the program LipiDex38. Shown is the fragmentation pattern of PE 40:6 confirming unsaturation in one chain. b, Profile and abundance of phosphatidylethanolamine in ROS membranes. Data are presented as mean values +/− SD (n = 3). A high degree of unsaturation is observed with the most abundant lipid assigned to PE 40:6. c, The reaction scheme of the formation of N-ret-PE. d, Detection of the formation of N-ret-PE 36:1. e, N-retinylidene-38:4 and f, N-retinylidene-40:5 under controlled illumination conditions and extraction into organic solvent for lipidomics. Negative ion mass spectra, monitoring the formate ion of the conjugated lipid, reveals a low intensity peak assigned through accurate mass to the N-retinylidene conjugate. Bar charts abundance ratio of N-ret-PE to free PE was monitored as a function of the illumination time and shows a clear decrease after 1 s for all three N-ret-PE lipids. Data are presented as mean values +/− SD (n = 3).
