Viral RNA synthesis, total protein synthesis and the synthesis
of specific poliovirus proteins were determined in the presence of
synergistic (low) and antagonistic (high) combinations of PAP and
guanidine. Viral proteins 3AB and 3C were blocked in the presence
of either guanidine or PAP at low concentration. In the presence of
the synergistic drug combination, proteins 2C, 2A and 3A, in
addition to proteins 3AB and 3C failed to appear. Also, proteins
3D, VPO and VP3 were present in reduced amount. The mechanism of
action of the synergistic drug combination may involve an
inhibition in the processing of poliovirus polyprotein P1 which is
the precursor protein for essential capsid endproducts VPO and
VP3.
Viral RNA synthesis was stimulated in the presence of either PAP
or guanidine alone at low concentration and in the presence of the
synergistic drug combination. This may be due to the absence of
protein VPg (3B) which has a regulatory function on RNA synthesis.
In contrast, viral RNA synthesis was inhibited almost completely in
the presence of either PAP or guanidine at high concentration and
in the presence of the antagon~sticd rug combination. The
antagonistic drug combination resulted in the failure to synthesize
plus-strand RNA from the parental RF-RNA which led to a complete
absence of viral protein synthesis.
