RESUMEN
The aim of this work was to design and characterize peptides based on the α-helices h1 and h2 of the ACE2 receptor, forming the interaction interface between the receptor-binding domain (RBD) of the SARS-CoV-2 S protein and the cellular ACE2 receptor. Monomeric and heterodimeric peptides connected by disulfide bonds at different positions were synthesized. Solubility, RBD-binding affinity, and peptide helicity were experimentally measured, and molecular dynamics simulation was performed in various solvents. It was established that the preservation of the helical conformation is a necessary condition for the binding of peptides to RBD. The peptides have a low degree of helicity and low affinity for RBD in water. Dimeric peptides have a higher degree of helicity than monomeric ones, probably due to the mutual influence of helices. The degree of helicity of the peptides in trifluoroethanol is the highest; however, for in vitro studies, the most suitable solvent is a water-ethanol mixture.
Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Humanos , Simulación de Dinámica Molecular , Péptidos , Unión Proteica , SARS-CoV-2Asunto(s)
Pneumocystis/fisiología , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/diagnóstico , Síndrome de Inmunodeficiencia Adquirida/microbiología , Animales , División Celular , Humanos , Infecciones Oportunistas/complicaciones , Infecciones Oportunistas/diagnóstico , Infecciones Oportunistas/microbiología , Pneumocystis/citología , Pneumocystis/patogenicidad , Infecciones por Pneumocystis/microbiología , Neumonía por Pneumocystis/complicaciones , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/microbiologíaRESUMEN
The use of scanning electron microscopy has made it possible to reveal the character of changes in the topography of cell surface at different periods after the inoculation of CHO cells with enteropathogenic Escherichia. The process of the adhesion of the strains under study to the surface of epithelial cells in the in vitro system has been found to consist of two phases. The second phase of adhesion is characterized by the appearance of specific structures, ruffles, on the surface of the cells.
Asunto(s)
Escherichia coli/patogenicidad , Ovario/microbiología , Animales , Células Cultivadas , Cricetinae , Cricetulus , Epitelio/microbiología , Epitelio/ultraestructura , Escherichia coli/ultraestructura , Infecciones por Escherichia coli/microbiología , Femenino , Haplorrinos , Microscopía Electrónica de Rastreo , Enfermedades de los Monos/microbiología , Ovario/ultraestructura , Propiedades de SuperficieRESUMEN
A cytopathic filterable agent designated EMC-70 was isolated in 1970 from Macaca rhesus monkeys with encephalomyocarditis. Its biologic and physico-chemical properties were studied. A number of primary and continuous cell cultures were found to be susceptible to the virus, and it was pathogenic for monkeys and small laboratory animals but did not multiply in chick embryos. The virus was stable to chlorofrom, thermolabile, stable to acids, and agglutinated group O erythrocytes of man, sheep, guinea pig. Electron microscopic examinations of infected cells revealed crystalline packings of subunits about 50 nm in diameter typical of picornaviruses. Serological studies demonstrated close antigenic relationship of the isolate with the virus belonging to encephalomyocarditis group.