Expression and purification of N and E proteins from severe acute respiratory syndrome (SARS)-associated coronavirus: a comparative study.

Histidine-tagged N (rNH) and E (rEH) proteins of Severe Acute Respiratory Syndrome (SARS)-coronovirus were expressed in the baculovirus/insect cell system and purified by immobilized metal affinity chromatography. rNH and rEH proteins differed markedly with respect to expression levels, cell death kinetics and subcellular localizations that led to different extraction and purification schemes. The features of both proteins are compared and the potential applications of purified rNH and rEH are discussed.