Figure 3.

The Y217N mutation in ACE2 significantly reduced the ability of ACE2 to bind the RBD and spike protein.A, HEK 293T cells were transfected with plasmids expressing the indicated ACE2 protein. At 24 hpt, the transfected cells were incubated with 5 μg RBD for 1 h at 37 °C, and then IFA and (B) western blotting were performed and RBD binding was quantified by densitometry scanning of western blot images by Image J software. Intensity of RBD binding for Human ACE2 was set as 1. C, HEK 293T cells were transfected with plasmids expressing the indicated ACE2 protein. At 24 hpt, the transfected cells were incubated with 5 μg S protein for 1 h at 37 °C, and then IFA and (D) western blotting were performed and S protein binding was quantified by densitometry scanning of western blot images by Image J software. Intensity of S protein binding for Human ACE2 was set as 1.