Polyacrylamide–agarose gel electrophoretic analysis of tobacco mosaic virus disassembly intermediates
The intermediates of disassembly of the U1, U4, U6, and U7 strains of tobacco mosaic virus (TMV) induced by alkali and urea were directly analysed by electrophoresis in composite polyacrylamide (2.0 to 2.5% (w/v)) – agarose (0.5% (w/v)) gels, using a discontinuous buffer system with Tris, borate, EDTA, and sodium chloride (pH 8.3). The results show no difference between the disassembly patterns of the four strains. In the case of alkaline stripping, two new major partially stripped virus (PSV) particles (PSV 5a and PSV 5c) and several minor intermediates were characterized. The overall results indicate that polyacrylamide–agarose gel electrophoresis is superior to agarose gel electrophoresis and to sucrose density gradient ccntrifugation for the analytical separation of PSVs. Polyacrylamide–agarose gel electrophoresis is thus a rather simple, rapid, and efficient method of studying in vitro disassembly of plant viruses.