ABSTRACT
Plants are endowed with a multitude of proteins and peptide compounds, and it would be expected, intuitively, that some of these could affect viruses in one or more ways, either by direct specific interaction with virions or indirectly by interfering with virus replication. There are several groups of plant proteins that exhibit fairly non-specific antiviral activity. Teltow et al. proceeded to determine the viral target of plant antiviral proteins (PAPs), by comparing the incorporation of radiolabeled precursors into viral DNA and proteins in uninfected and infected cells, with and without PAP. Since numerous plant extracts have been shown to possess similar protective effects, then this may indicate the existence of a fairly widespread family of plant antiviral proteins. In contrast to these nonspecific antiviral proteins, some extremely specific and very effective small peptides have been custom designed to interfere with the penetration stage of certain myxoviruses.
