Production and purification of PH(1–110)GFP particles

SF9 cells (2 × 10⁶ cel/ml) were infected using a multiplicity of infection (moi) of 10 with the recombinant baculoviruses, the cells were maintained at 27 °C under agitation at 100 RPM, 72 h post infection (hpi) the cultures were centrifuged at 4200 g for 15 min to recover the viruses and obtain the cell pellet. The pellets were resuspended in phosphate buffered saline (PBS, 137 mM NaCl, 2.7 mM KCl, 10 mM Na₂HPO₄, 2 mM KH₂PO₄, pH 7.4) and were sonicated with 5 cycles of 20 s per pulse with 30% amplitude (Qsonica 700, USA). Between each cycle were maintained on ice for 5 min. After the last cycle, the PH_(1–110) GFP particles were washed 5 times with PBS, between each wash the samples were centrifuged at 14,000 g. Finally, they were resuspended in PBS. In addition, chimeric polyhedra were generated by infecting SF9 cells with baculovirus with the WT polyhedrin and recombinant polyhedrin PH_(1–110) GFP.