Fig 4. MALDI-TOF/MS spectra of each GPL.

The molecular weights of GPLs derived from the mps1-complemented J15cs mutant were the same as those of the mc²155 strain. The matrix was 2,5-dihydroxybenzoic acid in chloroform-methanol (1:1, vol/vol). It was analyzed in the Reflectron mode with an accelerating voltage operating in positive mode at 20 kV. The main molecule-related ions were detected as m/z, [M+Na]⁺. Intens., intensity; a.u., arbitrary units. The mass numbers were fixed to the chemical structures and exact mass numbers.