Two approaches for the stabilization of Bacillus anthracis recombinant protective antigen

Figures & data

Figure 1. Spherical particles (SPs) generated by thermal remodeling of TMV. Scanning electron microscopy, without staining. Bar, 2 μm

Figure 2. The stability of rPA83 within complexes with SPs. 1, 3, 5, 7, 9, 11, 13 – rPA83 within SPs-rPA83 complexes incubated under +25°C for 0, 2, 4, 6, 8, 10 and 12 days, respectively. 2, 4, 6, 8, 10, 12, 14 – Individual rPA83 incubated under +25°C for 0, 2, 4, 6, 8, 10 and 12 days, respectively. 15 – Protein molecular weight markers (molecular weights in kDa are indicated in the right).Red arrows indicate the considerable difference in stability between individual rPA83 and rPA83 within SPs-rPA83 complexes. Electrophoresis analysis, staining by Coomassie G-250

Figure 3. Bacillus anthracis recombinant antigens form complexes with SPs and retain antigenic specificity within complexes. (I) SPs-rPA83 complexes; (II) SPs-rPA3 + 4 complexes. (I) Phase contrast (a) and fluorescence microscopy (b) of SPs-rPA83^FITC. (c) Immunoelectron microscopy of SPs-rPA83 complex. (II) Phase contrast (a) and fluorescence microscopy (b) of SPs-rPA3 + 4^FITC. (c) Immunoelectron microscopy of SPs-rPA3 + 4 complex. rPA83^{FITC –} rPA83 labeled with fluorescein isothiocyanate, rPA3 + 4^{FITC –} rPA3 + 4 labeled with fluorescein isothiocyanate. For detection by immunogold microscopy was used primary antibodies to the rPA83 and secondary antibodies conjugated with colloidal gold (d = 12 nm) (“Jackson immunoresearch”, USA)

Figure 4. Schematic representation of rPA3 + 4 protein. The amino acid sequence coordinates are given according to UniProt Q08G54. Epitopes and asparagine (N) to glutamine (Q) substitutions are indicated. The scheme is not to scale