Detection of partially proteolysed cauliflower mosaic virus coat protein in infected leaf tissue by Western blotting.

Cauliflower mosaic virus (CaMV) capsid polypeptides were detected by immunoelectroblotting ('Western blotting') 10-16 days after infection of Chinese cabbage leaves. The predominant polypeptides detected had molecular weights of 42,000 and 37,000 suggesting that in vivo proteolysis of the 55,000-58,000 molecular weight coat protein had taken place. The use of laboratory-made nitrocellulose membranes for Western blotting is reported. Phosphate-SDS buffer was more suitable than Tris-glycine buffer for the electrophoretic transfer of CaMV polypeptides. Specific antibodies prepared by absorption to intact CaMV were used as a probe for the viral coat proteins.