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.