Combined use of the hepatitis C drugs and amentoflavone could interfere with binding of the spike glycoprotein of SARS-CoV-2 to ACE2: the results of a molecular simulation study.

The worldwide rapid spread of the COVID-19 disease necessitates the search for fast and effective treatments. The repurposing of existing drugs seems to be the best solution in this situation. In this study, the molecular docking method was used to test 248 drugs against the receptor-binding domain (RBD) of spike glycoprotein of SARS-CoV-2, which is responsible for viral entry into the host cell.

DNA minor groove electrostatic potential: influence of sequence-specific transitions of the torsion angle gamma and deoxyribose conformations.

The structural adjustments of the sugar-phosphate DNA backbone (switching of the γ angle (O5'-C5'-C4'-C3') from canonical to alternative conformations and/or C2'-endo → C3'-endo transition of deoxyribose) lead to the sequence-specific changes in accessible surface area of both polar and non-polar atoms of the grooves and the polar/hydrophobic profile of the latter ones. The distribution of the minor groove electrostatic potential is likely to be changing as a result of such conformational rearrangements in sugar-phosphate DNA backbone. Our analysis of the crystal structures of the short free DNA fragments and calculation of their electrostatic potentials allowed us to determine: (1) the number of classical and alternative γ angle conformations in the free B-DNA; (2) changes in the minor groove electrostatic potential, depending on the conformation of the sugar-phosphate DNA backbone; (3) the effect of the DNA sequence on the minor groove electrostatic potential.

[The influence of the postoperative nutritional support on immune status in patients undergoing abdominal operations].

At the present day inclusion of the immune enhancing enteral nutrition in the program of the postoperative nutritional support is considered to be the most prospective method of the treatment of intestinal failure, hypermetabolism, hypercatabolism and systemic inflammatory response syndrome in patients undergoing abdominal operations. 60 patients, undergoing gastro-pancreaticoduodenal resections and gastrectomy, were examined. During the postoperative period the first group (experimental group) received standard enteral nutrition.

Sequence-specific transitions of the torsion angle gamma change the polar-hydrophobic profile of the DNA grooves: implication for indirect protein-DNA recognition.

Variations of the shape and polarity of the DNA grooves caused by changes of the DNA conformation play an important role in the DNA readout. Despite the fact that non-canonical trans and gauche- conformations of the DNA backbone angle γ (O5'-C5'-C4'-C3') are frequently found in the DNA crystal structures, their possible role in the DNA recognition has not been studied systematically. In order to fill in this gap, we analyze the available high-resolution crystal structures of the naked and complexed DNA.

Intermolecular hydrogen bonds in hetero-complexes of biologically active aromatic molecules probed by the methods of vibrational spectroscopy.

By the methods of vibrational spectroscopy (Infrared and Raman) the investigation of the hetero-association of biologically active aromatic compounds: flavin-mononucleotide (FMN), ethidium bromide (EB) and proflavine (PRF) was performed in aqueous solutions. It was shown that between the functional groups (CO and NH(2)) the intermolecular hydrogen bonds are formed in the hetero-complexes FMN-EB and FMN-PRF, additionally stabilizing these structures. An estimation of the enthalpy of Н-bonding obtained from experimental shifts of carbonyl vibrational frequencies has shown that the H-bonds do not dominate in the magnitude of experimentally measured total enthalpy of the hetero-association reactions.