Fig. 3

Expression analysis of recombinant proteins. a Northern blot analysis showing levels of Co1-scEDIII transcripts from selected transformants. Lane NC contains RNA from mock-transformed cells. Lanes 1–12 consist of RNA from the corresponding pYEG-Co1-scEDIII-TER transformants. Glyceraldehyde-3-phosphate dehydrogenase (GPD) transcription is shown as an internal control. Ribosomal RNA (rRNA) was used as a loading control. b Northern blot analysis showing levels of Co1-scEDIII-AGA transcripts from selected transformants. Lanes 1–10 consist of RNA from the corresponding pYEG-Co1-scEDIII-AGA-TER transformants. Lane NC contains RNA from mock-transformed cells. GPD transcription is shown as an internal control and rRNA was used as a loading control. c Western blot analysis of recombinant protein expression using anti-dengue IgG antibodies (lanes 2–10). Lane marked as ‘M’ represents pre-stained protein size marker. Their sizes (in kDa) are indicated to the left of the first lane. The arrow indicates the position of the recombinant scEDIII-Co1 protein. Lane 2 contains 1 µg of cell-free extract (CFE) from Escherichia coli-expressed scEDIII [14]. Lanes 3–9 contain 40 µg of CFE from recombinant Co1-scEDIII strains. Lane 10 contains 40 µg of CFE from Mock as negative controls. d Western blot analysis to confirm the expression of surface displayed recombinant Co1-scEDIII-AGA protein using anti-dengue IgG antibodies (lanes 2–7). Lane marked as ‘M’ represents pre-stained protein size marker. Their sizes (in kDa) are indicated to the left of the first lane. The arrow indicates the position of the recombinant Co1-scEDIII-AGA protein. Lane 2 contains 1 µg of CFE from E. coli-expressed scEDIII. Lane 3 contain 40 µg of CFE from wild type Saccharomyces cerevisiae 2805 strain. Lane 4 contain 40 µg of CFE from the Mock control. Lanes 5 and 6 contain CFEs and cell wall fractions from recombinant Co1-scEDIII-AGA strains, respectively. Lane 7 contains 10 mL of culture filtrate extracted from Co1-scEDIII-AGA strains