Souza et al. demonstrated that the binding energy between the S protein and ACE2 is 899.0 kJ·mol^(−1). Mo-CBP3-PepII and PepKAA have binding energies of 814.4 and −674.9 kJ·mol(−1) with the S protein, so they can successfully block its interaction with ACE2. Root-mean-square deviation (RMSD) analyses showed that Mo-CBP3-PepII and PepKAA had values of 1.331 and 1.342 which suggest that these peptides cause conformational changes in the S protein that would either prohibit or maladapt its bidning to ACE2.