Vaccinia-specific hemagglutinin

Abstract

Vaccinia-specific hemagglutinin (VHA) was reconstituted with the protein and phospholipid fractions prepared from vaccinia virus-infected cell membranes by treatment with sodium deoxycholate. The phospholipids of the IHD-J-strain virus (VHA +)-infected cells were replaceable in the constitution by pure phospholipids. In contrast, the protein fraction of VHA −-strain virus-infected cells or of uninfected HeLa cells showed no VHA activity after mixed dialysis with the phospholipid fractions. In addition to the VHA activity, heat stability and blocking capacity against specific anti-VHA serum were also regenerated when the VHA + protein was combined with phospholipids. The protein fraction of the VHA possessed all the specificities of vaccinia hemagglutinin. Three VHA-specific glycoproteins were identified (VHA P1: molecular weight (MW), 1.5 × 10 5; VHA P2: MW, 3.4 × 10 4; VHA P3: MW, 1.2 × 10 4) by sodium lauryl sulfate (SDS)-polyacrylamide-gel electrophoresis of VHA bound to chick erythrocytes. VHA P2 was found to be a subunit of VHA Pl. Host cell membrane protein (MW, 2.4 × 10 4), seems to be shifted to VHA P2 by VHA-specific glycosylation. The appearance of VHA activity on host cell plasma membranes is thus dependent on the VHA-specific glycosylation and polymerization of host glycoprotein and on the integration of VHA P1 in the membrane phospholipid bilayer.