VIEW ARTICLE

Physiology and Biochemistry

Purification and Partial Characterization of Maize Dwarf Mosaic Virus Strain A. G. von Baumgarten, Graduate student, Plant Pathology Department, University of Illinois, Urbana 61801; R. E. Ford, professor, Plant Pathology Department, University of Illinois, Urbana 61801. Phytopathology 71:36-41. Accepted for publication 2 June 1980. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-36.

Maize dwarf mosaic virus strain A (M-A) was extracted by blending infected leaf tissue in pH 9.0 buffer, precipitating the virus with 4% polyethylene glycol (PEG) in 0.3 M NaCl, and purifying it by centrifugation in the rate-zonal or quasi-equilibrium gradients. Purity was determined by UV absorption spectra and gel electrophoresis. M-A yields from fresh infected tissue were 10–20 μg/g. Virus coat protein migrated as a single component in sodium dodecyl sulfate (SDS) polyacrylamide gels with apparent molecular weights of 30,700 or 35,500 from untreated or carboxymethylated preparations, respectively. A minimum molecular weight of 29,137 was determined by amino acid analysis based on seven histidine residues per subunit. Major differences in number of amino acid residues per subunit between M-A and M-B (maize dwarf mosaic virus strain B), respectively, were glutamic acid 37 and 29, glycine 18 and 34, lysine 22 and 12, serine 15 and 20, and threonine 19 and 25.