A) Coomassie-stained SDS-PAGE gel of transiently expressed H5 and H5tr. Crude, clarified extracts were prepared from N. benthamiana leaves that were expressing the H5 and H5tr proteins transiently. The extracts were separated by SDS-PAGE and compared to known BSA concentrations after staining with Coomassie Blue. Lane 1, prestained protein ladder (Fermentas); lane 2, 6.25 μg BSA; lane 3, 3.12 μg BSA; lane 4, 1.56 μg BSA; lane 5, 0.78 μg BSA; lane 6, concentrated H5, lane 7 concentrated H5tr, lane 8, crude H5 extract, lane 9 crude H5tr extract. The arrow indicates the position of the H5 protein. B) Coomassie-stained SDS-PAGE gel of H5 expressed in stable transgenic plants. Apoplast-targeted H5 from transgenic plants was separated lanes 4 and 5. Lane 1, protein ladder (Fermentas); lane 2, 5 μg BSA; lane 3, 2.5 μg BSA; lane 4, crude H5 extract; and lane 5, concentrated H5.