Effect of Sulphydryl Reagents on the Biological Activities, Polypeptide Composition and Morphology of Haemagglutinating Encephalomyelitis Virus

Publisher Website
Google Scholar
Abstract
The effect of sulfydryl reagents on hemagglutinating encephalomyelitis virus (HEV), a coronavirus of pigs, was investigated. Using increasing concentrations of dithiothreitol (DTT), 50% of the virus infectivity and hemagglutination (HA) activity could be removed by 1.5 mM and 4-5 mM, respectively. The effect of DTT concentrations on the polypeptide composition was also examined. Of the 3 external glycoproteins gp 125 was the most susceptible, 50% being removed by incubation of the virus with 5-6 mM-DTT. Of the other 2 glycoproteins, gp 180 was unaffected by DTT concentrations up to 100 mM and the amount of gp 100 gradually declined at concentrations above 20 mM. The rates of removal of the virus HA activity and gp 125 suggested that this polypeptide was an essential part of the virus hemagglutinin. The lack of evidence for any interpeptide disulfide bonds suggested that the loss of these glycoproteins was due to an alteration in their conformation brought about by the cleavage of intrapeptide disulfide bonds. The loss of protein from the surface of the virus resulted in a change in the virus morphology with the appearance of thin fibrous projections instead of the characteristic petal-like coronavirus projections.

This publication has 2 references indexed in Scilit: