Chimeric hepatitis B virus core particles as probes for studying peptide-integrin interactions.
An RGD-containing epitope from the foot-and-mouth disease virus (FMDV) VP1 protein was inserted into the e1 loop of the hepatitis B virus core (HBc) protein. This chimeric protein was expressed at high levels in Escherichia coli and spontaneously assembled into virus-like particles which could be readily purified. These fusion particles elicited high levels of both enzyme-linked immunosorbent assay- and FMDV-neutralizing antibodies in guinea pigs. The chimeric particles bound specifically to cultured eukaryotic cells. Mutant particles carrying the tripeptide sequence RGE in place of RGD and the use of a competitive peptide, GRGDS, confirmed the critical involvement of the RGD sequence in this binding. The chimeric particles also bound to purified integrins, and inhibition by chain-specific anti-integrin monoclonal antibodies implicated alpha 5 beta 1 as a candidate cell receptor for both the chimeric particle and FMDV. Some serotypes of FMDV bound to beta 1 integrins in solid- phase assays, and the chimeric particles competed with FMDV for binding to susceptible eukaryotic cells. Thus, HBc particles may provide a simple, general system for exploring the interactions of specific peptide sequences with cellular receptors.
Chambers
M A
MA
Department of Biochemistry, Imperial College of Science, Technology and Medicine, London, United Kingdom.
Dougan
G
G
Newman
J
J
Brown
F
F
Crowther
J
J
Mould
A P
AP
Humphries
M J
MJ
Francis
M J
MJ
Clarke
B
B
Brown
A L
AL
Rowlands
D
D
D000818:Animals; D005537:Aphthovirus / Q000502:physiology*; D002460:Cell Line; D005260:Female; D006168:Guinea Pigs; D006512:Hepatitis B Core Antigens; D006515:Hepatitis B virus / Q000737:chemistry*; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D014758:Viral Core Proteins / Q000378:metabolism*
D006512:Hepatitis B Core Antigens; D016023:Integrins; D009842:Oligopeptides; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; D014758:Viral Core Proteins; C047981:arginyl-glycyl-aspartic acid