theme 2 examples Flashcards
what is chlorocyclizine
an antihistamine that that targets H1 histamine receptors and acts as an atagonist here
what type of receptor is H1
muscarinic
how does chlorocyclizine act in hepatitic C viral infection
it binds to the E1 envelope gylcoprotein. This prevents the virus from fusing with the host cell and therefore endocytocis of vral RNA
what is the difference betweeen endocytosis and exocytosis
endo - entering
exo - exiting
what is a glycoprotein
a protein that has carbohydrates attached
was the discovery of chlorocyclizine having activity against HCV a) moleculat target based screening or b) phenotypic screening
phenotypic
how was Gluc and cre recombinase used in the screen to assess Hepatitus C viral activity.
Host cells genetically engineered to express CAG promotor upstream of reporter gene - G.luciferase gene
Promotor separated by intervening sequence - prevents generation of luciferase
Intervening sequence flagged by cre recombinase - allows dna sections to be removed
Cre enzyme cuts at cre sites if present = promotor can drive luciferase expression
Cre enzyme encoded in virus = removal of intervening sequence = luciferase expression = luminescence
So if virus interferes with the cell then the cre recombinase enzyme will cut the interfering sequence out leading to luminescence. This is a method of seeing if viral activity is taking place.
what screening tool was used to cgaracgterise the formation of VEGFR2 homodimers and ligand binding ar VEGFR2 and how does this work
BRET - bioluminescent energy transfer:
both receptors are tagged with biolumiescent substrates that when in close proximity, the resonant energy transfer leads to biolumiecence energy emission.
in people with narcolepsy which neuron are they lacking
orexin neurons
what is orexin
plays a key role in wakefull ness. orexin binds to GPCRs to stimulate nueurotransmission and promote wakefullness.
what is an orphan receptor
a receptor that we do not know the endogenous ligand for
what is the role of CaSR
maintains calcium homeostasis. It inhibits synthesis and relase of parathyroid hormone. PTH stimulates bone resorporbion (bone matrix broken down and calcium stored in bones is released back into blood) and renal calcium reabsorbtion from waste filtred fluid into blood.
what drus acts to decrease calcium in the blood
cinacalet
does cincalet bind allosterically or orthosterically
allosterically
what is allosteric binding
binding to a site that is not the active site
how is herpes virus encoded GPCRS used as a drug target
herpes viraus encoded GCRS are proteins that are endoded by viral DNA so when a host cell is infected by a viruses DNA they express the viral GPCR on their surface membrane.
These GPCRs respond to human chemokines that stiumlate cell division. This is how viruses can lead to cancer as they can be uncontrolled cell growth and replication. Drugs that antagonise this receptor will prevent the growth and replication of the cell, preventing spread of the virus and tumor formation
describe the structure of a receptor tyrosine kinase
epidermal growth factors are receptors that contain a tyrosine kinase ezyme - receptor activation can activate this enzyme
Tere is an extracellular ninding region and an intracellular tyrosine kinase region
the ectracellular region can contain a dimerisation domain. opening og a dimerisation domain can be agonist led or sponateous
give an example of Human epidermal growth factor receptors and their link to disease
HER2 (ErbB2) - linked to breasr cancer
does inhibiton of the tyrosine kinase region effect KD
no. This only effects the efficacy. ie Emax
no effect to the binding of the extracellular domaon
what is Nintedanib
a multi-targeted tyrosine kinase inhibitor
for what interaction is BRET and FRET used for
Protein-protein
difference between BRET and FRET
B - biolummienscence - no excitatiry light needed
F - flourescence - excitatort light needed
proximity is the key thing we are measuring in both
close proximity = resonant energy transfer = signal
what is rampamycin
immunosurpessant used in transplant
what is the MOA of rapamycin
binfs to immunophilin FK506 binding protein = complex that inhibits kinase activarion = dec protain synthesis and cell cycle arrest (ie no cell division)
