G Protein Coupled Receptor GPCR Structure and functioning

>> YOUR LINK HERE: ___ http://youtube.com/watch?v=u_3cQqhmVK0

G-Protein-Coupled Receptor GPCR is most abundant and largest superfamily of receptors. • It mediate most cellular responses to hormones and neurotransmitters such as acetylcholine, epinephrine, dopamine, histamine, and serotonin. • The G protein–coupled receptors activation accounts for the actions of Almost half of all non-antibiotic prescription drugs. • The G-protein-coupled receptor comprises of #seven membranespanningαhelices coupled with G protein, these structural features give it several names such as seven transmembrane domain receptor, heptahelical receptor, #serpentinereceptor#Gproteinlinkedreceptor#GPLR, • The G-protein is key structural feature of #GPCR, The G proteins consist of three subunits α, β and γ. Guanine nucleotides bind to the α subunit, which also has enzymatic #GTPase activity and catalyze the conversion of GTP to GDP. • When GPCR is activated by binding of an agonist molecule to the extracellular ligand binding domain, a conformational change occurs which cause release of GDP from α subunit of G-protein, the dissociated GDP is replaced with GTP. • This change causes dissociation of the G protein trimer and release of α subunit with–GTP and β γ subunits remain together as a βγ complex. • The activated α subunit of the G protein causes various enzymes and ion channels activation and synthesis of #secondmessengers for an example stimulation #adenylylcyclase and synthesis of cAMP as a second messenger. • just pharmacology

#############################

New on site