An Infectious Nucleoprotein from Tobacco Mosaic Virus

Abstract

WE have reported previously the degradation of tobacco mosaic virus in alkaline solution into a series of sub-units, of which the molecular weights could be determined in the ultracentrifuge. By reaggregation of these sub-units, we obtained a protein that had the same size and shape as the virus itself, but was not infectious¹. Recently the process of degradation has been studied exhaustively by fractionating the products by electrophoresis. We carried out many experiments, varying the pH, the time of degradation and the temperature. We mention here only one typical pattern obtained three hours after adjusting the pH to 10.3 at 0° C, which is reproduced in Fig. 1 ; it shows five different boundaries, of which Nu has the highest and IV the lowest mobility. Each fraction was isolated for study; the results are listed in Table 1.