Figure 3. Effect of pH on the interaction between recombinant GST-AQP0-C and the recombinant filensin tail peptide. The filensin tail peptide was cleaved from the purified recombinant GST-fusion construct using preScission protease. Recombinant GST-AQP0-C and the recombinant filensin tail peptide were then incubated in different pH buffers and the interaction between the AQP0 COOH-terminal peptide and the filensin tail peptide was detected by western blotting with an anti-filensin tail antibody. Lanes 1, 2, 3, and 4 show the interaction between the filensin tail peptide and GST-AQP0-C in buffers with pH 7.0, 7.5, 8.0, and 8.5, respectively. Lane 5, GST alone incubated with the recombinant filensin tail peptide. Lane 6, purified filensin tail peptide cleaved from the GST-filensin tail fusion construct. Lane 7, GST-AQP0-C alone. Lane 8, GST alone.