Crystallization and X-ray analysis of the T = 4 particle of hepatitis B capsid protein with an N-terminal extension

Acta Cryst. (2007). F63, 642–647 [doi:10.1107/S1744309107033726]

[hepatitis B capsid] Electron density around the HBV capsid
The large hepatitis B virus (HBV) capsid has a molecular weight of about 4.25 MDa and comprises 240 copies of the core protein. Crystallization of a modified core protein containing an octapeptide N-terminal extension was found to be very dependent on temperature. The octapeptide extension was seen to protrude out from the surface of the capsid. This is consistent with the idea that N-terminal insertions can be exploited in the development of diagnostic reagents, multicomponent vaccines and gene delivery vehicles.
W.S. Tan, I.W. McNae, K.L. Ho and M.D. Walkinshaw