  SARS-CoV-2 is a global challenge due to its ability to spread much faster
than SARS-CoV, which was attributed to the mutations in the receptor binding
domain (RBD). These mutations enhanced the electrostatic interactions.
Recently, a new strain was reported in the UK that includes a mutation (N501Y)
in the RBD, that possibly increases the infection rate. Using Molecular
Dynamics simulations (MD) and Monte Carlo (MC) sampling, we showed that the
N501 mutation enhances the electrostatic interactions due to the formation of a
strong hydrogen bond between SARS-CoV-2-T500 and ACE2-D355 near the mutation
site. In addition, we observed that the electrostatic interactions between the
SARS-CoV-2 and ACE2 in the wild type and the mutant are dominated by
salt-bridges formed between SARS-CoV-2-K417 and ACE2-D30, SARS-CoV-2-K458,
ACE2-E23, and SARS-CoV-2-R403 and ACE2-E37. These interactions contributed more
than 40 % of the total binding energies.
