Subunit identification and reconstitution of the N-type Ca2+ channel complex purified from brain

Abstract

Calcium channels play an important role in regulating various neuronal processes, including synaptic transmission and cellular plasticity. The N-type calcium channels, which are sensitive to ω-conotoxin, are involved in the control of transmitter release from neurons. A functional N-type calcium channel complex was purified from rabbit brain. The channel consists of a 230-kilodalton subunit (α1B) that is tightly associated with a 160-kilodalton subunit (α2δ), a 57-kilodalton subunit (β3), and a 95-kilodalton glycoprotein subunit. The complex formed a functional calcium channel with the same pharmacological properties and conductance as those of the native ω-conotoxin-sensitive calcium channel in neurons.