Comparison of three different recombinant hepatitis B virus core particles expressed in Escherichia coli.
The properties of three different recombinant hepatitis B virus core proteins expressed in Escherichia coli were compared: an N-terminal fusion protein, a C-terminally truncated protein and a sequence-authentic protein. All three proteins assembled into capsid-like particles with typical HBc-antigenicity, sedimentation behavior and distinctive electron microscopical images. Apart from this, however, variant HBc proteins displayed properties different from sequence-authentic HBc protein p21.4. Unlike p21.4, the particles of the N-terminal fusion protein p22.2 were sensitive to proteolytic attack by trypsin at variable sites within its arginine-rich C-terminus but not in its extended N-terminus. We therefore conclude that the C-terminal region is located on the surface of the p22.2 particle. These particles also showed increased HBe-antigenicity, as did the C-terminally truncated core particles p17.6, and to an even greater extent p18* particles which were derived from p22.2 by tryptic digestion. This might be interpreted as evidence for an--albeit minor--structural change. All variant core particles were less stable and contained less RNA. Electron microscopic indication for DNA binding of C-terminal deleted p17.6 particles was obtained using an aqueous spreading technique.
Maassen
A
A
Institut für Biochemie, Medizinische Fakultät (Charité), Humboldt-Universität zu Berlin, Federal Republic of Germany.
Rehfeldt
A
A
Kiessig
S
S
Ladhoff
A
A
Höhne
W E
WE
Meisel
H
H
D000595:Amino Acid Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004926:Escherichia coli; D005814:Genes, Viral; D006512:Hepatitis B Core Antigens / Q000096:biosynthesis* / Q000302:isolation & purification / Q000648:ultrastructure; D006515:Hepatitis B virus / Q000235:genetics* / Q000378:metabolism; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000302:isolation & purification / Q000648:ultrastructure
D006512:Hepatitis B Core Antigens; D010446:Peptide Fragments; D011994:Recombinant Proteins