Fig. 1: Characterisation of antigen-bound IgG1 and IgG3.

a, b Slices 10 nm thick through tomograms of antigen-bound IgG1 (a) and IgG3 (b). Magnified regions (bottom) with membrane-to-Fc platform measurements. Scale bars represent 100 nm (top) and 50 nm (bottom). c Slice 5 nm thick through a subtomogram average of the ordered Fab domains viewed from the side. Two Fab domains are coloured violet and green, and membrane denoted as cyan. Repeating distance of 3.8 nm and 7 nm height of striations are shown. d Possible model of the Fab array from the same orientation as (b and c). Blue and yellow represent the heavy chain and the light chain of IgG3 Fab domains, respectively. e Slice 5 nm thick through a subtomogram average of aligned Fab domains observed at the apex of liposomes (Supplementary Fig. 5c, d). Two Fab domains are coloured violet and green, and repeating distances of 3.8 nm and 5.25 nm shown. f Possible model of the Fab array from the same orientation as (e), effectively rotated 90° from (b and c). Heavy and light chains are blue and yellow, respectively.