title: Folding properties of the hepatitis B core as a carrier protein for vaccination research.
abstract: The hepatitis B core (HBc) protein has been used successfully in numerous experiments as a carrier for heterologous peptides. Folding and capsid formation of the chimeric proteins is not always achieved easily. In silico analyses were performed to provide further comprehension of the feasibility for predicting successful capsid formation. In contrast to previous work, we show that common in silico predictions do not ensure assembly into particles. We included new considerations regarding capsid formation of HBc fusion proteins. Not only the primary sequence and the length of the inserts seem important, also the rigidity, the distance between the N and the C-terminus and the presence of cysteines, which could form disulphide bonds, could influence proper capsid formation. Furthermore, new conformational insights were formulated when linkers were added to create extra flexibility of the chimeric particles. Different hypotheses were suggested to clarify the obtained results. To this extent, the addition of glycine-rich linkers could lower high rigidity of the insert, removal of the strain of the core protein or ease interaction between the HBc and the insert. Finally, we observed specific changes in capsid formation properties when longer linkers were used. These findings have not been reported before in this and other virus-like particle carriers. In this study, we also propose a new high-yield purification protocol for fusion proteins to be used in vaccination experiments with the carrier protein or in comparative studies of particulate or non-particulate HBc fusion proteins.
authors: Department of Animal Health, Institute for Tropical Medicine, 155 Nationalestraat, 2000, Antwerp, Belgium. mjanssens@itg.be
authors: Michiel Etienne
authors: ME
authors: Janssens
authors: Dirk
authors: D
authors: Geysen
authors: Katleen
authors: K
authors: Broos
authors: Ine
authors: I
authors: De Goeyse
authors: Johan
authors: J
authors: Robbens
authors: Filip
authors: F
authors: Van Petegem
authors: Jean-Pierre
authors: JP
authors: Timmermans
authors: Yves
authors: Y
authors: Guisez
mesh_terms: D000595:Amino Acid Sequence; D004247:DNA / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005822:Genetic Vectors; D006512:Hepatitis B Core Antigens / Q000008:administration & dosage*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006801:Humans; D008969:Molecular Sequence Data; D017510:Protein Folding
chemical_list: D006512:Hepatitis B Core Antigens; D017325:Hepatitis B Vaccines; D004247:DNA