“…In previous research, only the RBD domain of the spike protein was used in the analysis of binding affinity with ACE2: no MD analysis of the structure optimization ( Celik et al, 2022 ; Gan et al, 2021 ; Shah and Woo, 2021 ; Sitthiyotha and Chunsrivirot, 2021 ; Tragni et al, 2022 ) and/or local optimization of only the RBD domain of the spike protein ( Celik et al, 2022 ; Gan et al, 2021 ; Kumar et al, 2022 ; Shah and Woo, 2021 ; Sitthiyotha and Chunsrivirot, 2021 ; Tragni et al, 2022 ; Xue et al, 2021 ). However, we chose the three-dimensional structure of the complete trimeric spike protein (PDB ID: 6ZGG ) in homology modeling in this research.…”