Table 2. In silico targeted mutagenesis studies of the SARS-CoV-2 receptor-spike interaction with various amino acid mutations.

Mutations were conducted with the swapaa command in UCSF Chimera, and bound structures were minimized with 2000 steps of steepest descent. D (blue) signifies dampened molecular motion, NC (yellow) indicates no significant change in molecular motion as a result of binding, and A (orange) indicates an amplification in molecular motion after RBD binding. Significance criteria was determined as having <= −1 KL divergence or less (dampened motion during binding), or >=1 KL divergence or more (amplified motion during binding). N-terminal helix and AAQPFLL motif categorization was determined as dampened or amplified when most of their constituent amino acids had a KL divergence of <= −1 or >= 1, respectively.

Protein	In silico Mutation	N-terminal Helix	Q325	K353	386-AAQPFLL-392
	Wild Type	D	NC	D	D
ACE2	K353A	NC	NC	D	D
ACE2	386-AA/EE-387	D	D	D	D
ACE2	390-FLL/EEE-392	D	NC	D	D
ACE2	V739E	NC	NC	D	NC
ACE2	V739L	D	D	D	NC
ACE2	K408A	D	NC	D	D
RBD	V185E	NC	NC	D	NC
RBD	V185L	D	D	D	NC