Tetracycline as an inhibitor to the SARS‐CoV‐2

AbstractThe coronavirus severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) remains an extant threat against public health on a global scale. Cell infection begins when the spike protein of SARS‐CoV‐2 binds with the human cell receptor, angiotensin‐converting enzyme 2 (ACE2). Here, we address the role of tetracycline as an inhibitor for the receptor‐binding domain (RBD) of the spike protein. Targeted molecular investigation show that tetracycline binds more favorably to the RBD (−9.40 kcal/mol) compared to doxycycline (−8.08 kcal/mol), chloroquine (−6.31 kcal/mol), or gentamicin (−4.83 kcal/mol) while inhibiting attachment to ACE2 to a greater degree (binding efficiency of 2.98 kcal/(mol nm2) for tetracycline–RBD, 5.16 kcal/(mol nm2) for doxycycline–RBD, 5.59 kcal/(mol nm2) for chloroquine–RBD, and 7.02 kcal/(mol nm2) for gentamicin–RBD. Stronger inhibition by tetracycline is verified with nonequilibrium PMF calculations, for which the tetracycline–RBD complex exhibits the lowest free energy profile along the dissociation pathway from ACE2. Tetracycline binds to tyrosine and glycine residues on the viral contact interface that are known to modulate molecular recognition an