Interaction analyses of SARS-CoV-2 spike protein based on fragment molecular orbital calculations

Kazuki Akisawa, Ryo Hatada, Koji Okuwaki, Yuji Mochizuki, Kaori Fukuzawa, Yuto Komeiji, Shigenori Tanaka

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


At the stage of SARS-CoV-2 infection in human cells, the spike protein consisting of three chains, A, B, and C, with a total of 3300 residues plays a key role, and thus its structural properties and the binding nature of receptor proteins to host human cells or neutralizing antibodies has attracted considerable interest. Here, we report on interaction analyses of the spike protein in both closed (PDB-ID: 6VXX) and open (6VYB) structures, based on large-scale fragment molecular orbital (FMO) calculations at the level of up to the fourth-order Møller-Plesset perturbation with singles, doubles, and quadruples (MP4(SDQ)). Inter-chain interaction energies were evaluated for both structures, and a mutual comparison indicated considerable losses of stabilization energies in the open structure, especially in the receptor binding domain (RBD) of chain-B. The role of charged residues in inter-chain interactions was illuminated as well. By two separate calculations for the RBD complexes with angiotensin-converting enzyme 2 (ACE2) (6M0J) and B38 Fab antibody (7BZ5), it was found that the binding with ACE2 or antibody partially compensated for this stabilization loss of RBD.

Original languageEnglish
Pages (from-to)3272-3279
Number of pages8
JournalRSC Advances
Issue number6
Publication statusPublished - 2021 Jan 14

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)


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