SARS coronavirus: unusual lability of the nucleocapsid protein.


The severe acute respiratory syndrome (SARS) is a contagious disease that killed hundreds and sickened thousands of people worldwide between November 2002 and July 2003. The nucleocapsid (N) protein of the coronavirus responsible for this disease plays a critical role in viral assembly and maturation and is of particular interest because of its potential as an antiviral target or vaccine candidate. Refolding of SARS N-protein during production and purification showed the presence of two additional protein bands by SDS-PAGE. Mass spectroscopy (MALDI, SELDI, and LC/MS) confirmed that the bands are proteolytic products of N-protein and the cleavage sites are four SR motifs in the serine-arginine-rich region-sites not suggestive of any known protease. Furthermore, results of subsequent testing for contaminating protease(s) were negative: cleavage appears to be due to inherent instability and/or autolysis. The importance of N-protein proteolysis to viral life cycle and thus to possible treatment directions are discussed.

DOI: 10.1016/j.bbrc.2008.09.153

Cite this paper

@article{Mark2008SARSCU, title={SARS coronavirus: unusual lability of the nucleocapsid protein.}, author={John K Mark and Xuguang Li and Terry D. Cyr and Sylvie M Fournier and Bozena Jaentschke and Mary Alice Hefford}, journal={Biochemical and biophysical research communications}, year={2008}, volume={377 2}, pages={429-433} }