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Hemagglutination and structural polypeptides of a new coronavirus associated with diarrhea in infant mice
Abstract:
The hemagglutination (HA) and receptor destroying enzyme (RDE) activities of a newly isolated mouse enteric coronavirus (designated as DVIM) are described. DVIM agglutinates mouse or rat red blood cells (RBC) at 4 degrees C. At 37 degrees C the agglutination was rapidly reversed. The optimal pH for HA and for RDE activities using mouse red cells were shown to be 6.5 and 7.3 respectively. Hemagglutination by DVIM was not inhibited by pretreatment of RBCs with Vibrio cholerae filtrate or by pretreatment with Influenza-A neuraminidase. Therefore, the DVIM receptors on RBCs differ from the receptors of Influenza-A, and the RDE activity of DVIM acts specifically on this receptor. In addition, an analysis of the DVIM polypeptides showed that the virions contain five major, VP1 (M.W. 139,000), VP2 (68,000), VP3 (53,000), VP4 (38,000), VP5 (22,000) and two minor, VP1a (110,000), VP1b (100,000) polypeptides. VP1 and VP1b were digested by bromelain, suggesting that they constitute the surface glycoproteins.
Insights
A novel mouse enteric coronavirus, DVIM, exhibits hemagglutination and receptor destroying enzyme activities. Its specific receptors on red blood cells differ from influenza-A, indicating unique viral interactions.
Area of Science:
- Virology
- Molecular Biology
Background:
- Coronaviruses are significant pathogens affecting various hosts.
- Understanding viral surface proteins and their interactions is crucial for antiviral development.
Purpose of the Study:
- To characterize the hemagglutination (HA) and receptor destroying enzyme (RDE) activities of a newly isolated mouse enteric coronavirus (DVIM).
- To analyze the polypeptide composition of DVIM virions and identify surface glycoproteins.
Main Methods:
- Assessing hemagglutination and RDE activities of DVIM using mouse and rat red blood cells at different temperatures and pH.
- Investigating receptor specificity by testing inhibition with Vibrio cholerae filtrate and Influenza-A neuraminidase.
- Analyzing viral polypeptides using SDS-PAGE and bromelain digestion.
Main Results:
- DVIM agglutinates mouse/rat red blood cells at 4°C, with rapid reversal at 37°C.
- Optimal HA and RDE activity occurred at pH 6.5 and 7.3, respectively.
- DVIM receptors are distinct from Influenza-A receptors, and its RDE activity is specific.
- DVIM virions possess five major and two minor polypeptides, with VP1 and VP1b identified as potential surface glycoproteins.
Conclusions:
- DVIM possesses unique hemagglutination and RDE properties, suggesting a novel mechanism of host cell interaction.
- The identified surface glycoproteins are likely involved in DVIM's receptor binding and entry.
- This study provides foundational insights into the molecular characteristics of mouse enteric coronaviruses.