Calcium Channel Toxins Flashcards
What are the three roles of voltage gated calcium channels (VGCCs)?
Excitation-contraction coupling.
Secretory coupling.
Intracellular signalling.
What is the function of the alpha-1 subunit of a VGCC?
Pore forming, so conducts calcium.
What is the function of the beta subunits of a VGCC?
Confer localisation and voltage-gating.
What is the function of the alpha2-delta subunit of a VGCC?
Localisation and full current passage.
Where is the N type calcium channel found?
Exclusively neuronal.
Where is the P type calcium channel found?
Purkinje cells.
Where is the Q type calcium channel found?
Cerebellar granule cells.
Where is the R type calcium channel found?
Neuronal/cardiac/gut.
Describe omega-conotoxin GVI-A.
27 amino acid peptide.
N-type (Cav2.1) selective.
Irreversible pore blocker.
Describe omega-agaotoxin.
89 amino acid peptide.
P/Q type (Cav2.2) selective.
Irreversible gating blocker.
Describe SNX-482.
41 amino acid peptide.
R-type (Cav2.3) selective.
Pore blocker.
Define neuropathic pain.
A pain that is caused by nociceptive neuronal dysfunction and cannot be controlled by analgesics.
What do current therapies for neuropathic pain target?
Alpha2-omega subunits of VGCC.
