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BIMM118
Receptors
• Rapidly acting (milliseconds) transmembrane ion channels: Multi-unit complexes
with central aqueous channel. Upon binding of a ligand, channel opening allows a
specific ion travel down its concentration gradient ==>
Transient cell membrane depolarization (post synaptic potential)
• Example: Nicotinic acetylcholine receptor: Pentameric structure (two alpha chains, one each
beta, gamma, and delta chain). Activation occurs by binding of two molecules ACh to the alpha
subunits, triggering the opening of the channel for Na + and K + ions.
Myasthenia gravis: Autoimmune disease caused by inactivating antibodies against NAchR