Fig. 5.

Sensorgrams for wild-type G-CSF (left panel) and triple His variant clone 757 (right panel) binding to immobilized G-CSF receptor at pH 7.4 (top panel) and pH 5.5 (bottom panel). G-CSF injections were performed at both 25 and 50 nM G-CSF concentration at pH 7.4 and 100 and 200 nM G-CSF concentration at pH 5.5 to ensure adequate binding signals at acidic pH. Black lines denote measured instrument response units. Orange lines denote model fits.