Engineering pH responsive fibronectin domains for biomedical applications

Table 2 Flow cytometry MFU values for CA-displaying yeast incubated with biotinylated EGFR after ligand-free buffer incubation

Fn3 Domain	EGFR Concentration (nM)	MFU - pH 5.5 Pre-incubation	MFU - pH 7.4 Pre-incubation
Wild Type Clone A	1.5	1370 +/− 100	1340 +/− 100
Wild Type Clone A	4.0	1850 +/− 160	1650 +/− 100
F48H	4.0	650 +/− 20	620 +/− 80
F48H	12	1270 +/− 40	1200 +/− 100
T49H	1.5	1200 +/− 40	1250 +/− 120
T49H	4.0	1460 +/− 120	1600 +/− 30
F48H/T49H	12	150 +/− 10	160 +/− 20
F48H/T49H	25	220 +/− 30	240 +/− 20

Wild type and His variant CA-diplaying yeast were incubated with various concentrations of biotinylated EGFR in pH 7.4 PBS-BSA after one hour incubation in ligand-free PBS-BSA with pH adjusted to either 5.5 or 7.4. EGFR concentrations were chosen to match or be similar to those at which reductions in CA EGFR binding affinity at pH 5.5 relative to pH 7.4 were most clearly broken out in K_D titrations. Values represent averages for two independent trials. Error bars denote standard deviations

ISSN: 1754-1611