The soluble hemagglutinins of adenoviruses belonging to Rosen's subgroup 3. I. The rapidly sedimenting hemagglutinin.

Abstract

Soluble components of adenovirus types 1, 2, 5 and 6 were separated by anion exchange chromatography. Four different components eluting in the following sequence were demonstrated: Incomplete hemagglutinin (HA), identifiable only in the presence of antisera against members ofRosen's subgroup III (i.e. fibers), early and late eluting complete HA, only the latter of which was markedly enhanced in the presence of anti-sera against members of any ofRosen's three subgroups (i.e. pentons), and group-specific complement-fixing (CF) antigen (i.e. hexons). In preparations of serotypes 5 and 6 the major part of the complete HA was of the late-eluting, penton-associated form, whereas the complete HA of types 1 and 2 mainly were early eluting. Pentons prepared by anion exchange chromatography were fractionated by zonal centrifugation in sucrose gradients or exclusion chromatography. Two populations of pentons were distinguishable. The one with the larger mass carried complete HA activity the titer of which was increased in the presence of heterotypic antisera against members of all ofRosen's, subgroups. The other population of pentons could only function as an incomplete HA, identifiable by group-specific hemagglutination enhancement. Toxin activity was carried by both populations of pentons. Trypsin treatment destroyed the toxin activity and eliminated the HA activity, complete or incomplete, of both populations of pentons. Incubation of isolated complete penton HA at 56° C resulted in a dissociation into incomplete penton and fiber HA. It is assumed that the incomplete penton HA represents isolated pentons, whereas an aggregation of two to four pentons into a polyvalent complex is as prerequisite for a complete HA activity. This assumption is supported for adenovirus type 6 by electronmicroscopy.