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5 Cards in this Set
- Front
- Back
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Influenza surface proteins |
Haemagglutinin (HA) - binds to sialic acid (sugar) on host cell = entry Neuraminidase (NA) / sialidase - removes sialic acid from newly formed virus particle as it emerges and stops them sticking together = allows new virus particle to escape |
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Types of influenze |
16 types of HA 9 types of NA all found in birds but only H1, H2, & H3 can infect humans (molecular recognition just for these) |
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Host range of influenza (HA) |
Bird HA binds to receptors with a2,3 linkages Human adapted HA binds to sialic acid receptors with a2,6 linkages Pigs have both types of receptors |
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Pig as mixing vessel |
Pig infected with more than one virus -> genetic recombination - new virus mutates and is passed on to new species ie humans (because now has human characteristics ie HA) |
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Neuraminidase drug design |
Block the activity of NA, then the virus cannot leave the cell/spread. 1. See how natural substrate (sialic acid) binds to active site 2. Look to make new compound that fits better (ie has negatively charged pocket) 3. Put NH3+ group in place of OH (binds 100 x better) 4. Put Arg (+ve charge) in place of OH. (Binds 10,000x better) ie refenza and tamiflu |
