RESUMO
The human parechovirus 1 RGD motif in VP1 was studied by mutagenesis. An RGD-to-RGE change gave only revertant viruses with a restored RGD, while deletion of GD was lethal and nonrevertable. Mutations at the +1 and +2 positions had some effect on growth properties and a +1 M-to-P change was lethal. These studies indicate that the RGD motif plays a critical role in infectivity, presumably by interacting with integrins, and that downstream amino acids can have an influence on function.
Assuntos
Oligopeptídeos , Picornaviridae/fisiologia , Proteínas Virais/genética , Replicação Viral , Sequência de Aminoácidos , Arginina , Ácido Aspártico , Glicina , Humanos , Dados de Sequência Molecular , Mutação , Picornaviridae/genética , Alinhamento de SequênciaRESUMO
A number of Thai medicinal plants, recommended as remedies for herpesvirus infection and have been used in primary health care were investigated for their intracellular activities against herpes simplex viruses (HSV). Centella asiatica L., Maclura cochinchinensis Cornor, and Mangifera indica L. contained both anti-HSV-1 and -2 activities, as determined by plaque inhibition assay. An inhibition of the production of infectious HSV-2 virions from infected Vero cells could also be demonstrated. Combinations of each of these reconstituted extracts with 9-(2-hydroxyethoxymethyl) guanosine (acyclovir; ACV) resulted either in subadditive, additive, or synergistic interaction, against HSV-2, depending on the dose of ACV used; mixture of C. asiatica and M. indica exerted an additive effect in a similar assay. Furthermore, the inhibitory effects of these plant extracts were also substantiated by flow cytometric analysis of virus-specific antigens in the infected cells. The active constituent present in C. asiatica extract was determined to be asiaticoside while in M. indica was mangiferin. Thus, these data suggest therapeutic potential of these plant extracts.
