Related Experiment Videos
Isolated HE-protein from hemagglutinating encephalomyelitis virus and bovine coronavirus has receptor-destroying and
B Schultze1, K Wahn, H D Klenk
1Institut für Virologie, Philipps-Universität Marburg, Federal Republic of Germany.
Abstract:
Bovine coronavirus (BCV) and hemagglutinating encephalomyelitis virus (HEV) from swine were found to grow to high titers in MDCK I cells, a subline of Madin Darby canine kidney cells. Virus grown in these cells was used to isolate and purify the HE-protein. This protein has been shown recently to have acetylesterase activity and to function as the receptor-destroying enzyme of BCV. Here we show that HEV contains this enzyme, too. The glycoproteins were solubilized by treatment of virions with octylglucoside. Following centrifugation through a sucrose gradient the surface proteins S and HE (hemagglutinin-esterase) were obtained in purified form. After removal of the detergent by dialysis, HE formed rosettes as shown by electron microscopy. The purified HE protein retained acetylesterase activity and was able to function as a receptor-destroying enzyme rendering red blood cells resistant against agglutination by both coronaviruses. HE protein released from the viral membrane failed to agglutinate red blood cells. However, it was found to recognize glycoconjugates containing N-acetyl-9-O-acetylneuraminic acid as indicated by a binding assay with rat serum proteins blotted to nitrocellulose and by its ability to inhibit the hemagglutinating activity of BCV, HEV, and influenza C virus. The purified enzyme provides a useful tool for analyzing the cellular receptors for coronaviruses.
Insights
Bovine coronavirus (BCV) and hemagglutinating encephalomyelitis virus (HEV) hemagglutinin-esterase (HE) protein was purified and shown to possess acetylesterase activity. This enzyme degrades cellular receptors, aiding in coronavirus research.
Area of Science:
- Virology
- Biochemistry
- Cell Biology
Background:
- Bovine coronavirus (BCV) and hemagglutinating encephalomyelitis virus (HEV) are significant pathogens.
- The hemagglutinin-esterase (HE) protein is a key viral surface glycoprotein involved in receptor binding and enzymatic activity.
- Previous studies identified HE-protein's acetylesterase activity and receptor-destroying enzyme function for BCV.
Purpose of the Study:
- To investigate the presence and function of the HE-protein in HEV.
- To isolate and characterize the HE-protein from both BCV and HEV.
- To explore the potential of purified HE-protein as a tool for studying coronavirus-receptor interactions.
Main Methods:
- High-titer virus propagation in MDCK I cells.
- Solubilization of viral glycoproteins using octylglucoside.
- Purification of HE-protein via sucrose gradient centrifugation.
- Enzymatic assays for acetylesterase activity and receptor-destroying enzyme function.
- Binding assays using nitrocellulose-blotted proteins and hemagglutination inhibition tests.
Main Results:
- HEV, similar to BCV, possesses HE-protein with acetylesterase activity.
- Purified HE-protein from both viruses functions as a receptor-destroying enzyme, rendering red blood cells resistant to viral agglutination.
- The HE-protein recognizes N-acetyl-9-O-acetylneuraminic acid-containing glycoconjugates.
- Purified HE-protein inhibited hemagglutination by BCV, HEV, and influenza C virus.
Conclusions:
- The HE-protein of HEV shares functional similarities with that of BCV.
- Purified HE-protein is a valuable tool for elucidating cellular receptor structures for coronaviruses.
- Understanding HE-protein function provides insights into viral pathogenesis and host-pathogen interactions.