Structure and composition of influenza virus. A small-angle neutron scattering study |
| |
Authors: | S Cusack R W Ruigrok P C Krygsman J E Mellema |
| |
Institution: | European Molecular Biology Laboratory, Grenoble Outstation c/o ILL, 156X, 38042 Grenoble Cedex, France;Department of Biochemistry, University of Leiden Wassenaarsweg 64, Leiden, The Netherlands |
| |
Abstract: | A detailed analysis is presented of the small-angle neutron scattering curves of homogeneous solutions of influenza B virus, both intact and after treatment with bromelain, which removes the external glycoprotein spikes. The two sets of data are consistent with the following low-resolution structure: the virus particles are spherical, about 1200 A in diameter and of Mr about 180 X 10(6). The lipid bilayer is centred at a radius of 425 A, is 40 A to 50 A thick and constitutes 25% to 28% of the virus mass. The surface glycoproteins, predominantly haemagglutinin, contribute 40% to 46% of the total mass. Surprisingly little protein is found in the interior of the virus. It is suggested that the reason for this is that many particles do not contain the full complement of ribonucleoprotein complexes. These results are in good agreement with recent scanning transmission electron microscopic measurements of molecular mass and cryo-electron microscopic observations of the same preparations. Appendix 1 describes a new method of deriving spherical shell models from contrast variation neutron scattering data on viruses, in which scattering curves from all measured contrasts are used simultaneously. There is also a discussion of the assumptions and limitations implicit in the structural interpretation of such models, with emphasis on viruses containing lipid bilayers. Appendix 2 examines the effect on the scattering curves of various arrangements of the surface glycoproteins. |
| |
Keywords: | STEM scanning transmission electron microscopy HK Hong Kong |
本文献已被 ScienceDirect 等数据库收录! |
|