Skip to main content
. 2013 Mar;33(5):1041–1056. doi: 10.1128/MCB.00811-12

Fig 6.

Fig 6

Validation and identification of IPCs. (A) MS precursor and MS/MS fragmentation spectrum for IPC 44:0;4 from WT yeast. The observed precursor ion m/z 952.681 represents the expected ion IPC 44:0;4 (952.686). The observed m/z 835.529 corresponds to the two PIs, PI 16:0-18:1 and PI 16:1-18:0, used to normalize the relative abundance of each IPC species. In the lower MS/MS spectra of the 952.681 precursor ion, the first and second most abundant peaks correspond to the expected IPC 44:0;4 fragment ions [ceramide phosphate-H2O]− at m/z 772.62 and [ceramide phosphate]− at m/z 790.63. (B) Theoretical fragmentation database for IPCs 38:0;4, 40:0;4, 42:0;4, and 46:0;4. Shown are the theoretical m/z values for fragment ions [ceramide phosphate-H2O]− and [ceramide phosphate]− for IPCs 38:0;4, 40:0;4, 42:0;4, and 46:0;4. (C) MS/MS fragmentation spectra for IPCs 38:0;4, 40:0;4, 42:0;4, and 46:0;4. The observed precursor m/z values “Pre” of 868.586, 896.617, 924.648, and 980.712 correspond to the expected m/z values of IPC 38:0;4 (868.592), IPC 40:0;4 (896.623), IPC 42:0;4 (924.655), and IPC 46:0;4 (980.717), respectively. In the MS/MS spectra, the peaks corresponding to the expected theoretical IPC fragment ions [ceramide phosphate-H2O]− and [ceramide phosphate]− are marked with an asterisk. In each case, the peak corresponding to the expected [ceramide phosphate-H2O]− fragment ion was the most intense ion in the MS/MS spectrum.