Biophysical Properties of Purified Morphologic Forms of Hepatitis B Antigen

Abstract

The morphological forms of hepatitis B antigen (HBsAg) present in an HBsAg-positive plasma (15–25 nm spheres, filaments 20–22 nm in diameter and 80–300 nm in length, and 42 nm Dane particles) were isolated and characterized biophysically. The HBsAg in this plasma was fractionated into five distinct populations, containing predominately 15–19 nm spheres, 20–22 nm spheres, 20 × 300 nm filaments, a mixture containing 23–25 nm spheres and rare filaments, and 42 nm Dane particles, respectively. These populations were labeled with 125I and electrofocused in a pH ampholyte gradient. Each population had a distinct isoelectric pH with values ranging from 3.65 to 4.70. Sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis of each of the above labeled populations revealed the presence of 7, 10, 9, 5, and 9 polypeptides, respectively. The population containing predominately 23–25 nm spheres failed to react with antibody specific for HBsAg and probably was composed of inner cores of the Dane particles.

Association of normal serum protein antigens with chimpanzee hepatitis B surface antigen particles

“…The polypeptide composition for human HBsAg has been previously reported by others [Chairez et al, 1974;Chairez et al, 1975;Gerin, Shih, and Kaplan, 1975;Shih and Gerin, 19771. Our findings for chimpanzee HBsAg are in good agreement with those of human preparations.…”

Biochemical and Biophysical Properties of Hepatitis B Core Particles Derived from Dane Particles and Infected Hepatocytes

“…Analysis of polypeptides by PAGE in a discontinuous system using SDS, mercaptoethanol (ME) and urea to denature proteins, as described previously [14], was performed with the following modifications. Instead of cylindrical gels, the gel was cast in a slab 0.75 mm thick, using slots 10 mm wide formed in the stacking gel mixture (Hoeffer Scientific Instruments, San Francisco, Calif.).…”

“…Electrophoresis of 125I-IabeIed and unlabclcd HBcAg was per formed in an LKB electrofocusing apparatus at 4° and at 500 V for 60 h in a pH gradient of 3-6 as previously described by this laboratory [ 14]. The gradient was eluted from the bottom of the column by pumping 0.5% phenol red into the top and collecting 2-ml fractions.…”

Polypeptide composition of HBsag

“…This may be due to the purification procedure employed. In the report, by CItAtREZ et al (3,4) it was described that preparations of HBsag containing particles of varying size as well as preparations from the two subtypes of HBsag contain a different number of polypeptides. This may explain the differences found by various workers both in the number and the molecular weights of the HBsag polypeptides.…”