SDS-PAGE gel of filament preparations showing a single band corresponding to a, OmcS purified from ΔomcZ strain and c, OmcZ from KN400 strain. Corresponding TEM images of b, OmcS and e, OmcZ nanowires. Scale bars, 400 nm. Solution CD spectra of c, OmcS and f, OmcZ is similar to CD spectra of OmcS and OmcZ nanowires purified from wild-type and W51W57 strains respectively (Fig. 6c, d). M1 and M2 represent nanowires sheared from cells by two different methods – vortexing (M1) and blending (M2).