Fig. 1

Quality control of chimeric HBcAg-VLPs. a 6His is a chimeric HBcAg construct containing a C-terminally located short linker followed by a hexahistidine-peptide (GGSH6, black box), for details see Klamp et al. [38] The chimeric HBcAg construct ΔHis indicates deletion of the linker and polyhistidine-peptide. Arrow head: cysteine residue at position 61. b Expression and purification analysis of chimeric VLPs by 12% NuPAGE stained with colloidal Coomassie. Lanes 1 and 2: whole cell lysates from non-induced (1) and induced cells (2), respectively. Lanes 3 and 4: supernatants after removal of cell debris (3) or overnight heat treatment (4), respectively. Lane 5: resuspended protein sediment after AMS-precipitation. Lane 6: purified and reassembled chimeric VLPs. c PageBlue stained native agarose gel analysis of HBcAg-VLPs (lane 6 from b). The triangulation number of T = 4-VLPs and T = 3-VLPs are designated. The lower row panel represents a dot blot analysis of identical spotted protein amounts of both VLPs, using mAb3120, specifically detecting assembled particles. d Polypeptides were identified by immunoblotting of chimeric VLPs (compare lane 6 in b) using anti-HBcAg (mAb 2–10aa, α-HBcAg) or anti-hexahistidine-peptide (α-His)