FIGURE 5.

Binding of yeast-expressed CH2, m01s, Fc, and CH3 to shFcRn at pH 6 (red) and pH 7.4 (blue). A very slight fluorescence intensity shift occurred in the case of CH2, indicating very weak binding to shFcRn. A modest fluorescence intensity shift was observed in the case of m01s, indicating modest binding to shFcRn. The largest fluorescence intensity shift was observed in the case of Fc, indicating strong binding to shFcRn. CH3 did not bind to shFcRn in a pH-dependent manner; there was no observable fluorescence intensity shift. The expression of CH2, m01s, Fc, and CH3 was tested by the corresponding antibodies. PE-streptavidin was used as negative control.