Figure 1: The cytoplasmic domain of mIgG interacts with acidic but not zwitterionic lipids.
From: Acidic phospholipids govern the enhanced activation of IgG-B cell receptor
(a) Schematic representations of IgM-BCR, IgG-BCR and biochemical characteristic analysis of the cytoplasmic domain of mIgM, mIgG, Igα and Igβ. Acidic, basic and hydrophobic residues are respectively coloured in blue, red and green. ITT motif in mIgG-tail is underlined. (b) FP assay to measure binding of CP488-mIgG-tail peptide to zwitterionic lipid POPC bicelles (q=0.8), acidic lipid POPG or POPS bicelles and mixture lipid bicelles (60% POPC, 30% POPS, 10% POPG). FP value was detected in different lipids concentration of 10, 5, 250, 1 and 2.5 mM. All the FP value was normalized to FP value in solution. Bars represent mean±s.d. from three repeated experiments. (c,d) Tryptophan fluorescence emission spectrum assay to detect binding of mIgG-tail peptide to acidic lipid POPS bicelles (c) and zwitterionic lipid POPC bicelles (d) at different concentration of lipids as indicated. Shown was one representative of three independent experiments.
