The previously reported (Partridge et al., Nature 247, 391–392, 1974R9 ) glycosylation of the capsid proteins of cowpea mosaic virus (CPMV) has been reinvestigated. In initial studies, a preparation of purified CPMV particles was hydrolysed with HCl and amino acids and sugars were derivatized with o-phthalaldehyde (OPA). No glucosamine or galactosamine, amino sugars previously reported to occur in significant quantities in CPMV capsids, could be detected by reverse-phase high-performance liquid chromatography (RP-HPLC) of the derivatized hydrolysates. A complete analysis of all sugars potentially present was carried out by hydrolysing a sample of purified CPMV capsid proteins and derivatizing the sugars with 1-phenyl-3-methyl-5-pyrazolone. RP-HPLC analysis demonstrated that the capsids do not contain significant quantities of any sugar. The results show that, contrary to the previous report, the coat proteins of CPMV are not glycosylated.
Altmann, F. (1992). Determination of amino sugars and amino acids in glycoconjugates using precolumn derivatization with o-phthalaldehyde.Analytical Biochemistry204, 215-219.[CrossRef][Google Scholar]
Fu, D. & O’Neill, R. A. (1995). Monosaccharide composition analysis of oligosaccharides and glycoproteins by high-performance liquid chromatography.Analytical Biochemistry227, 377-384.[CrossRef][Google Scholar]
Goldbach, R. W. & van Kammen, A. (1985). Structure, replication and expression of the bipartite genome of cowpea mosaic virus. In Molecular Plant Virology, pp. 83-120. Edited by J. W. Davies. Boca Raton, FL: CRC Press.
Goldbach, R. W. & Wellink, J. (1996). Comoviruses: molecular biology and replication. In The Plant Viruses, pp. 35-76. Edited by B. D. Harrison & A. F. Murant. New York: Plenum Press.
Lomonossoff, G. P. & Hamilton, W. D. O. (1999). Cowpea mosaic virus-based vaccines.Current Topics in Microbiology and Immunology240, 177-189.
[Google Scholar]
Lomonossoff, G. P. & Johnson, J. E. (1991). The synthesis and structure of comovirus capsids.Progress in Biophysics and Molecular Biology55, 107-137.[CrossRef][Google Scholar]
Lomonossoff, G. P. & Johnson, J. E. (1995). Eukaryotic viral expression systems for polypeptides.Seminars in Virology6, 257-267.[CrossRef][Google Scholar]
Miele, L. (1997). Plants as bioreactors for biopharmaceuticals: regulatory considerations.Trends in Biotechnology15, 45-50.[CrossRef][Google Scholar]
Partridge, J. E., Shannon, L. M., Gumpf, D. J. & Colbaugh, P. (1974). Glycoprotein in the capsid of plant viruses as a possible determinant of seed transmissibility.Nature247, 391-392.[CrossRef][Google Scholar]
Spall, V. E., Porta, C., Taylor, K. M., Lin, T., Johnson, J. E. & Lomonossoff, G. P. (1998). Antigen expression on the surface of a plant virus for vaccine production. In Engineering Crop Plants for Industrial End Uses, pp. 35-46. Edited by P. R. Shewry, J. A. Napier & P. J. Davis. London: Portland Press.
Taylor, K. M., Spall, V. E., Butler, P. J. G. & Lomonossoff, G. P. (1999). The cleavable carboxyl-terminus of the small coat protein of cowpea mosaic virus is involved in RNA encapsidation.Virology255, 129-137.[CrossRef][Google Scholar]
Tozzini, A. C., Ek, B., Palva, E. T. & Hopp, H. E. (1994). Potato virus X coat protein: a glycoprotein.Virology202, 651-658.[CrossRef][Google Scholar]
van Kammen, A. & de Jager, C. P. (1978). Cowpea mosaic virus. CMI/AAB Descriptions of Plant Viruses, no. 197.
Wu, G.-J. & Bruening, G. (1971). Two proteins from cowpea mosaic virus.Virology46, 506-512.[CrossRef][Google Scholar]