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The total impact of the worldwide COVID‐19 pandemic is still emerging, changing all relationships as a result, including those with pet animals. In the infection process, the use of angiotensin‐converting enzyme 2 (ACE2) as a cellular receptor to the spike protein of the new coronavirus is a fundamental step. In this sense, understanding which residue plays what role in the interaction between SARS‐CoV‐2 spike glycoprotein and ACE2 from cats, dogs, and ferrets is an important guide for helping to choose which animal model can be used to study the pathology of COVID‐19, and if there are differences between these interactions and those occurring in the human system. To help answer these questions, we performed classical molecular dynamics simulations to evaluate, from an atomistic point of view, the interactions in these systems. Our results show that there are significant differences in the interacting residues between the systems from different animal species, and the role of ACE2 key residues are different in each system, and can assist in the search for different inhibitors for each animal. [ABSTRACT FROM AUTHOR]

The barley HvAACT1 gene codes for a citrate transporter associated with tolerance to acidic soil. In this report, we describe a single nucleotide polymorphism (SNP) in the HvAACT1 coding region that was detected as T-1,198 (in genotypes with lower root growth on acidic soil) or G-1,198 (greater root growth) and resulted in a single amino acid change (L/V-172). Molecular dynamic analysis predicted that HvAACT1 proteins with L or V-172 were stable, although the substitution led to structural changes within the protein. To evaluate the effect of the SNP on tolerance to acidic soil, barley accessions were separated into haplotypes based on the presence of a 1 kb insertion in the HvAACT1 promoter and a 21 bp insertion/deletion. These markers and the SNP-1,198 allowed the identification of five haplotypes. Short-term soil experiments showed no difference in root growth for most of the accessions containing the 21 bp insertion and T or G-1,198. In contrast, genotypes showing both the 21 bp deletion and G-1,198, with one of them having the 1 kb insertion, showed greater root growth. These results indicate that the SNP was not advantageous or deleterious when genotypes from the same haplotype were compared. The occurrence of the SNP was highly correlated with the 21 bp insertion/deletion that, together with the 1 kb insertion, explained most of the barley tolerance to acidic soil.

Malaria is the most prevalent parasitic disease in the world. Currently, an effective vaccine for malaria does not exist, and chemotherapy must be used to treat the disease. Because of increasing resistance to current antimalarial drugs, new treatments must be developed. Among the many potential molecular targets, the hexose transporter of Plasmodium falciparum (PfHT) is particularly promising because it plays a vital role in glucose transport for the parasite. Thus, this study aims to determine the three-dimensional structure of PfHT and to describe the intermolecular interactions between active glycoside derivatives and PfHT. Such information should aid in the development of new antimalarial drugs. The receptor PfHT was constructed from primary sequences deposited in the SWISS MODEL database. Next, molecular docking simulations between O-(undec-10-en)-l-D-glucose and the constructed active site models were performed using Autodock Vina. The glycoside derivative-PfHT complexes were then refined using the hybrid QM/MM (PM3/ff03) method within the AMBER package. The models were then evaluated using Ramachandran plots, which indicated that 93.2% of the residues in the refined PfHT models (P5) were present in favorable regions. Furthermore, graphical plots using ANOLEA showed that the potential energies of interaction for atoms unbonded to P5 were negative. Finally, the O-(undec-10-en)-l-D-glucose-PfHT complex was evaluated using 20-ns Molecular Dynamics simulations with an ff03 force field. Docking and QM/MM studies revealed the amino acids essential for molecular recognition of and activity on glycosides. Inhibition of glucose transporters may prevent the development and metabolism of P. falciparum, so a description of the receptor's structure is a critical step towards rational drug design., (Copyright © 2016 Elsevier Inc. All rights reserved.)