ABSTRACT
Interaction between the SARS-COV-2 (2019 novel coronavirus) spike protein and ACE2 receptors expressed on cellular surfaces initialises viral attachment and consequent infection. Blocking this interaction shows promise for blocking or ameliorating the virus' pathological effects on the body. By contrast to work focusing on the coronavirus, which has significant potential diversity through possible accumulation of mutations during transmission, targeting the conserved ACE2 protein expressed on human cells offers an attractive alternative route to developing pharmacological prophylactics against viral invasion. In this study, we screened a virtual database of natural peptides in silico, with ACE2 as the target, and performed structural analyses of the interface region in the SARS-COV-2 RBD/ACE2 complex. These analyses have identified 15 potentially effective compounds. Analyses of ACE2/polypeptide interactions suggest that these peptides can block viral invasion of cells by stably binding in the ACE2 active site pocket. Molecular simulation results for Complestatin and Valinomycin indicate that they may share this mechanism. The discovery of this probable binding mechanism provides a frame of reference for further optimization, and design of high affinity ACE2 inhibitors that could serve as leads for production of drugs with preventive and therapeutic effects against SARS-COV-2. Communicated by Ramaswamy H. Sarma.