Monthly Archives: July 2011

A measure of successful virus entry

There are numerous techniques that can be used to examine the interactions between the virus and the cell. These techniques can generally fall into two categories: direct and indirect observation. Direct observation uses familiar techniques such as thin-section microscopy, cryo-electron microscopy, tomography, and other less familiar techniques like freeze-fracture immunolabeling to examine virus-cell interactions. When […]

Adsorption and receptor recognition. Part 2

As arboviruses, alphaviruses infect insect and vertebrate hosts. Since alphaviruses need to infect cells which provide widely divergent biochemical and genetic environments, it is likely that they either use a ubiquitous receptor, or are able to use multiple proteins as a receptor. The receptor/s has not been identified. Many proteins and polysaccharides have been implicated […]

Adsorption and receptor recognition

A second caveat which seriously affects the quality of the data is that the entity to be studied not be distorted by the ability of proteins to be manipulated and expressed in some form in E. coli. There are currently crystal structures of an E1-E2 fusion protein (PDB codes 3MUU), chikungunya glycoproteins (PDB codes: 3N40;3N41;3N42;3N43;3N44;2XFB;2XFC) […]

Alphavirus Structure. Part 2

The current molecular model for how the virus transfers its RNA into the cell is hypothesized to be by low pH mediated membrane fusion, after endocytosis of the virus attached to its receptor. E2 contains the receptor binding sequence while E1 is known to contain the properties necessary for membrane fusion. It is predicted that […]

Alphavirus Structure

Alphaviruses are small 70 nm viruses that have 240 copies each of three structural proteins, E1, E2 and capsid (C) assembled in a 1:1:1 stoichiometry. These three proteins create two nested T = 4 icosahedral shells that sandwich a host derived lipid bilayer. The outer protein shell is composed of E1 and E2 heterodimers that […]