2.1  Pdb files
The SARS-CoV-2 spike protein trimer in the prefusion conformation was obtained from pdb file # 6VSB [20]. Hydroxychloroquine (CLQ-OH) is (RS)-2-[{4-[(7-chloroquinolin-4-yl)amino]pentyl}(ethyl)amino]ethanol. CLQ-OH was generated by hydroxylation of chloroquine (CLQ) and validated as previously described [10]. CLQ was retrieved from pdb file # 4V2O (CLQ co-crystallized with saposin B) [21].
Azithromycin (ATM) is (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-11-[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-2-ethyl-3,4,10-trihydroxy-13-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-3,5,6,8,10,12,14-heptamethyl-1-oxa-6-azacyclopentadecan-15-one. The 3D structure of ATM was obtained from pdb file # 5UXD (ATM co-crystallized with macrolide 2′-phosphotransferase) [22].