TABLE 2.

SPR affinity

FcRn dissociation constants and affinity increases in the YTE mutant were estimated from SPR binding data. Steady-state analysis (SS) considers only the magnitude of SPR response versus concentration of analyte at 300 seconds, whereas kinetic analysis determines affinity by consideration of the on- and off- rates versus concentration. ND, not determined.

Condition	Low density FcRn			High density FcRn
	WT	YTE	WT/YTE	WT	YTE	WT/YTE
	nm	nm		nm	nm
SS — pH 5.5	96	20	4.8	26	28	1
Kinetics 5.5	8	2	4	5	0.4	12.5
SS — pH 7.4	1561	701	2.2	407	30	13.5
Kinetics 7.4	ND	318	ND	528	9	58