Journal of General Virology - Volume 4, Issue 4, 1969

Mycophenolic acid, produced by various species of the genus Penicillium, has been shown to have both antibacterial and antifungal properties (see Korzybski, Kowszyk-Gindifer & Kurylowicz 1967). Mycophenolic acid was found to be antiviral in tissue culture. The Agar Diffusion Test (Herrmann et al. 1960) was employed, using 100 µg. per well. It gave zones of plaque inhibition of 40 to 60 mm. against vaccinia, herpes simplex, Semliki Forest, encephalomyocarditis, Coxsackie (Bl, conn. 5) and influenza (A-nws) viruses. The degree of inhibition against vaccinia virus compared favourably with that obtained with the known antivaccinial compounds iododeoxyuridine (80 mm.) and methisazone (75 mm.). When incorporated into the agar overlay in a normal plaque technique, it was found that the median plaque inhibitory concentration was 0.3 to 1 µg./ml. for vaccinia virus, the same as that obtained with iododeoxyuridine and methisazone.

Several picornaviruses appear to contain more than one polypeptide chain. When examined by polyacrylamide gel electrophoresis, poliovirus (Maizel, 1963; Maizel & Summers, 1968) and mouse encephalomyocarditis virus (Burness & Walter, 1967), each gave four bands and mouse encephalitis virus gave three bands (Rueckert & Duesberg, 1966). The most reasonable explanation for these observations is that each of the viruses contains more than one polypeptide chain; but the multiplicity of the bands could be due to chemical modification of certain amino acids in the virus protein during the experiment or to aggregation or breakdown of a single protein. Vande Woude & Bachrach (1968) considered that the multiplicity of bands they obtained from foot-and-mouse disease virus was due to aggregation of a single polypeptide. However, Wild, Burroughs & Brown (1969) used a double labelling technique and concluded that the multiple bands obtained with this virus are not due to aggregation of a single polypeptide chain.

S. T. Cowan (1968). A Dictionary of Microbial Taxonomic Usage, pp. x+118. Edinburgh: Messrs Oliver & Boyd. 42s.

R. C. Nairn (ed.) (1969). Fluorescent Protein Tracing, 3rd ed. pp. xvi + 503. Edinburgh: E. & S. Livingstone Ltd. 60s.