CHARACTERIZATION OF PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS HEMAGGLUTININ

Porcine reproductive and respiratory syndrome virus hemagglutinin (HAi n) was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on goose erythrocytes. The adsorbed HAin could not be elute d from the cells by resuspending in phosphate buffered saline, by incu bating at 37 or 50 degrees C, or by incubating in the presence of neur aminidase. The hemagglutinating activity was not dependent on the pH a nd NaCl molarity tested. The receptor of mouse erythrocytes for the HA in was relatively stable to trypsin, neuraminidase, sodium deoxycholat e (DOC), potassium periodate (KlO(4)), dithiothreitol (DTT), 2-mercapt oethanol (2-ME) and formalin treatments. The HAin was inactivated by 2 -ME and was gradually inactivated by pepsin, formalin and DTT, but not by beta-glucosidase, trypsin, alpha-amylase, papain, phospholipase C, neuraminidase, KlO(4), and ethylendiamine tetraacetic acid (EDTA) tre atments. The HAin was stable at 37 degrees C or lower temperatures, bu t not at 56 degrees C or higher. The HAin was relatively resistant to ultraviolet irradiation and sonication. In the equilibrium centrifugat ion of the HAin preparation on a CsCl density gradient, the HAin activ ity showed a sharp peak at 1.17 g/cm(3). In the SDS-PAGE analysis, the structural polypeptide of HAin in the peak fraction seems to be the n ucleocapsid (N) polypeptide with molecular weight of 15 kDa.