Deciphering the molecular details of interactions between anti-COVID drugs and functional human proteins: in silico approach.

The molecular docking calculations have been employed to investigate the interactions a set of proteins with the repurposed anti-COVID drugs. The position of the therapeutic agents within the protein structure was dependent on a particular drug-protein system and varied from the binding cleft to the periphery of the polypeptide chain. Interactions involved in the drug-protein complexation includes predominantly hydrogen bonding and hydrophobic contacts. The obtained results may be of particular importance while developing the anti-COVID strategies as well as for deeper understanding of the drug pharmacodynamics and pharmacokinetics.

Probing the interactions of novel europium coordination complexes with serum albumin.

Molecular interactions between novel europium coordination complexes (EC) possessing superior cytotoxic activity and bovine serum albumin (BSA), the most prominent representative of plasma proteins, were assessed using fluorescence spectroscopy and molecular docking techniques. Cumulative results from fluorescent probe binding, fluorescence quenching and Förster resonance energy transfer studies revealed that the europium complexes V4 and V8 do not perturb the BSA structure, while V3, V5, and V7 induce partial unfolding of the polypeptide chain. Molecular docking studies coupled with analysis of the three-dimensional structure of the BSA-EC complexes showed that V4 and V8 reside in the vicinity of the protein IIA subdomain (Sudlow's site I), while V3, V5 and V5 were localized predominantly in the BSA IIIA subdomain (Sudlow's site II). Due to the intactness of the protein structure upon association with V4 and V8, these compounds may be recommended for further evaluation as potential antineoplastic agents.

Novel benzanthrone aminoderivatives for membrane studies.

The potential of novel benzanthrone aminoderivatives to trace the changes in physicochemical properties of lipid bilayer has been evaluated. Binding of the dyes to the lipid bilayers composed of zwitterionic phospholipid phosphatidylcholine (PC) and its mixtures with anionic phospholipid cardiolipin (CL) and cholesterol (Chol) was followed by significant quantum yield increase with small blue shift of emission maximum. Analysis of partition coefficients of the dyes under study showed that all aminobenzanthrones possess high lipid-associating ability. The dyes A8 and AM2 proved to be sensitive to the variations in membrane chemical composition responding to the changes in bilayer hydration induced by CL and Chol.