jmone at MARAUDER.MILLERSV.EDU
Fri May 2 11:31:19 EST 1997
The most common mechanism to change viral capsid or spike proteins is by
a process known as antigenic drift. RNA viruses such as HIV and
influenza have the ability to acquire point mutations in the genes
encoding the spike proteins gp120 (HIV-1) or hemagglutinin (influenza).
These point mutations result in subtle changes in the globular structure
of the spikes, resulting in changes in the antigenicity of the proteins.
RNA viruses are more prone to antigenic drift than are DNA viruses,
probably due to the high error rate of RNA polymerases (as high as 10-4,
as compared with DNA polymerases (10-8). However, changes in surface
antigenicity is only one of many ways in which viruses avoid immune
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