Fig. 7.

ESI–Q-TOF MS¹ and MS² spectra of antibody-detected Gb3Cer species from GMVECs. a MS¹ spectrum. The spectrum was obtained from pooled silica gel extracts of four TLC overlay assays corresponding to 2 × 10⁵ cells. A representative overlay assay performed with a lipid extract from 5 × 10⁴ cells is shown in the inset whereby the framed dotted rectangle indicates the areas from which the silica gel was scraped off. b–d MS² spectra. The arrowheads denote the positions of immunoreactive Gb3Cer lipoforms selected for MS² analysis. A synopsis of the m/z values of [M+Na]⁺ ions obtained from TLC immunodetected Gb3Cer and Gb4Cer as well as their proposed structures are provided in Table 1. e Molecular structure and auxiliary fragmentation scheme of Gb3Cer (d18:1, C16:0)