Antiviral activity of chondroitin sulfate against infection by tobacco mosaic virus

Abstract

In the course of searching for antiviral substances against the tobacco mosaic virus (TMV), it was found that chondroitin sulfate (Chs) A-type and C-type had a high inhibitory activity against TMV infection. The addition of Chs to the inoculum solution greatly reduced the number of local lesions formed on Xanthi NN tobacco leaves. The degree of inhibition increased with Chs concentration and was higher in C-type than A-type, which suggests that the strength of inhibition relates to the stiffness of the polymer chain of Chs. For Chs C-type inhibition was independent of molecular weight where the molecular weight was between 30000 and 70000, and decreased with molecular weight below 30000. The electron micrograph showed that the TMV suspension itself was almost monodisperse and that the addition of Chs caused TMV to form large raftlike aggregates. The TMV solution became turbid after the addition of a large amount of Chs. The antiviral activity of Chs on the infectivity of TMV may be caused by blocking the decapsulation process of TMV protein on the cell membrane surface.