A Difference between the Sub-Units of Tobacco Mosaic Virus Protein?

Abstract

IN an earlier investigation the protein fractions of two wild strains of tobacco mosaic virus and four mutation strains, which were derived from them, were compared analytically. In parallel with every mutational step small differences in the amino-acid composition could be demonstrated¹. The virus preparations used in these investigations have been derived from inoculations steadily propagated during many years. Thus we should consider them genetically to be populations, and perhaps as not uniform in the composition of their protein fractions. New material is now available from three of the earlier investigated strains : vulgare, flavum and necans. The new preparations have passed at least two single lesion inoculations before propagation. So they may be considered as uniform as experimentally possible. I used only preparations from plants with symptoms which are in good agreement with those earlier described^2,3. The amino-acids of tobacco mosaic virus protein were estimated by Levy's technique⁴.