The E3 protein of bovine coronavirus is a receptor-destroying enzyme with acetylesterase activity.

Department of Microbiology, Mount Sinai School of Medicine, New York, New York 10029-6574.
Journal of Virology (Impact Factor: 4.65). 01/1989; 62(12):4686-90.
Source: PubMed

ABSTRACT In addition to members of the Orthomyxoviridae and Paramyxoviridae, several coronaviruses have been shown to possess receptor-destroying activities. Purified bovine coronavirus (BCV) preparations have an esterase activity which inactivates O-acetylsialic acid-containing receptors on erythrocytes. Diisopropyl fluorophosphate (DFP) completely inhibits this receptor-destroying activity of BCV, suggesting that the viral enzyme is a serine esterase. Treatment of purified BCV with [3H]DFP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the proteins revealed that the E3 protein was specifically phosphorylated. This finding suggests that the esterase/receptor-destroying activity of BCV is associated with the E3 protein. Furthermore, treatment of BCV with DFP dramatically reduced its infectivity in a plaque assay. It is assumed that the esterase activity of BCV is required in an early step of virus replication, possibly during virus entry or uncoating.

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May 31, 2014

Reinhard Vlasak