Demonstration of subpopulations of Dane particles

Abstract

Two populations of Dane particles were isolated from the plasma of individuals carrying hepatitis B surface antigen. These populations had densities in CsCl of 1.22 and 1.20 g/ml. Endogenous DNA polymerase activity was found to be associated only with the heavier of these two populations. Using a positive stain, electron microscopic examination of these particles suggested that the heavier the particle contained nucleic acid in its core whereas the lighter particle appeared empty. Cores isolated from Dane particles with densities of 1.22 and 1.20 g/ml banded in CsCl at densities of 1.36 and 1.30 g/ml, respectively. Endogenous DNA polymerase activity was associated only with the higher density core particles.

Demonstration and partial characterization of an intermediate HBcAg (dane particle) population

“…These differences could be explained by differences in DNA size and different lengths of the single-stranded gaps. This study confirms data presented by Kaplan et al [1976], showing that completion of the single-stranded gaps known to constitute between 15% and 45% of the total DNA length [Robinson et al, 19741 particles to explain the differences in buoyant density found between heavy and intermediate HBcAg particles solely by differences in DNA size. Sucrose gradient analysis of DNA isolated from heavy and intermediate HBcAg particles revealed, however, that they were of approximately equal size.…”

“…The present paper extends data on the heterogeneity of Dane particles [Kaplan et al, 1976;Shih et al, 19801. The use of shallow CsCl gradients and appropriate centrifugation conditions allowed resolution of an intermediate HBcAg (Dane particle) population and determination of some of the characteristics associated with this population.…”

“…The Dane particle represents a minor population of all particles exposing hepatitis-B surface antigen (HBsAg) determinants that circulate in sera of individuals acutely or chronically infected with the hepatitis-B virus (HBV) [Almeida et al, 1971;Dane et al, 1970;Hess et al, 1979;Kaplan et al, 1976;S h h et al, 19801. It is the only HBsAg form to exhibit a complex morphology and is composed of an inner core [hepatitis-B core antigen (HBcAg)] in addition to its outer shell (HBsAg) [Almeida et al, 1971;Dane et al, 1970;Hess et al, 1979;Kaplan et al, 1976;Shih et al, 19801. A subpopulation of Dane particles contains a circular double-stranded DNA with single-stranded regions constituting between 15% and 45% of its total length [Robinson et al, 19741 and a DNA-dependent DNA polymerase [Kaplan et al, 1973;Kaplan et al, 19761. Thls Dane particle population is considered to be the complete HBV.…”

“…Thls Dane particle population is considered to be the complete HBV. Most Dane particles are believed to lack DNA and a DNA polymerase and thus t o represent defective HBY [Hess et al, 1977[Hess et al, , 1979Kaplan et al, 1976;Shih et al, 19801. Both Dane particle populations can be separated from the 22 nm HBsAg forms by their buoyant density, which was found to be 1.24 gm/ml for heavy Dane particles and 1.22 gm/ml for light Dane particles [Kaplan et al, 1976;Shih et al, 19801.…”

In Vitro Replication and Expression of Hepatitis B Virus From Chronically Infected Primary Chimpanzee Hepatocytes

“…HBc/eAg was localized predominantly to a density of 1.30 to 1.32 gm per cm3. These are characteristic banding densities for HBsAg molecules and of immature core particles (30). Additional HBc/e reactivity was observed at the density of 1.17 to 1.19 gm per cm3, which may reflect disrupted particles or free HBeAg (31).…”