antiviral drugs against influenza virus Flashcards
what is the classification of influenza virus
order: articulavirales
family: orthomyxoviridae
which 3 flu strains infect humans
a,b,c
which strains do not cause a pandemic yet
b and c
which strain can cause global pandemic
a
which strains cause human disease
a, b ,c
how is influenza transmitted
respiratory secretions
what are formites
generate droplets that settle on surfaces
what does influenza target
respiratory tract
name some symptoms
tiredness
sore throat
runny nose
head ache
fever
cough
muscle aches
what are the 3 membrane proteins of influenza
HA-trimer most abundant
NA-tetramer
M2-tetramer
how many segments in the virus interior
8 which comprise the viral genes
what is virus attachment mediated by
HA
what does HA recognise in order to attach
sialic acid
which cells are commonly modified by galactose
ciliated epithelial cells
how does virus escape from the endosome
virus envelope fuses with endosome membrane.
HA helps with this and changes conformation because of low PH
how do segments get out of the matrix
4x M2 proteins form a pore
H+ influx
what sense are the segments and what does transcription do to them
negative
then become coding
how are the virus mRNAs transcribed
via polymerase
what subunits are in the polymerase and where are the 2 active sites
PA- active site for endonucleases
PB1 -active site for polymerisation
PB2
how does an endonuclease collect mRNA caps
1.PB2 binds cap on mRNA
2. PA cleaves it off
3.cap and RNA fragment passed to PB1
4.RdRp moves toward 5’ end of template and copies
how has the virus solved the problem HA binding to sialic acid on old cells
NA cleaves sialic acid on already infected cell so a new cell can be infected
amantadine is the anti viral compound what was it specific for
influenza A
what was rimantadine
an improved antiviral with an additional methyl group
how did theses adamantanes work
prevent M2 ion channel activity
what are the two binding sites on M2
within central pore
within membrane facing pocket
how did the virus become resistant to these
mutations in M2
amantadine could no longer bind and block
what does the Xofluza drug do
inhibits PA endonuclease active site
the discovery of the 5 contacts of the NA-SA interaction led to the discovery of what
relenza
tamiflu
repivab
what do the above drugs do
block NA active site
