RECOGNITION OF CELLULAR RECEPTORS BY BOVINE CORONAVIRUS

Bovine coronavirus (BCV) initiates infection by attachment to cell sur face receptors the crucial component of which is N-acetyl-9-O-acetylne uraminic acid. Inactivation of receptors by neuraminidase treatment an d restoration of receptors by enzymatic resialylation of asialo-cells is described as a method to determine (i) the type of sialic acid that is recognized; (ii) the linkage specificity of the viral binding acti vity; (iii) the minimal amount of sialic acid required for virus attac hment. Evidence is presented that both glycoproteins and glycolipids c an serve as receptors for BCV provided they contain 9-O-acetylated sia lic acid. A model is introduced proposing that after initial binding t o sialic acid-containing receptors, the S-protein of BCV interacts wit h a specific protein receptor. This interaction may result in a confor mational change that exposes a fusogenic domain and thus induces the f usion between the viral and the cellular membrane.