- de Weille, J.R. et al. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 2437.
- Alomone Labs Calciseptine inhibits CaV1.2 channel current expressed in Xenopus oocytes.A. Representative time course of Calciseptine (#SPC-500) inhibition of CaV1.2 channel currents. Membrane potential was held at -100 mV, current was elicited by a 100 ms voltage ramp to +60 mV every 10 sec, and significantly inhibited by application of 1 µM Calciseptine (green). B. Superimposed traces of CaV1.2 current after application of control (black) and of 1 µM Calciseptine (green), taken from the recording in A.
Calciseptine is a peptide toxin originally isolated from the Dendroaspis p. polylepsis black mamba venom1 and shown to be a specific L-type CaV channel blocker2. However, in skeletal muscle, it increases L-type currents3.
Calciseptine blocks spontaneous or K+-induced contraction of cardiac and smooth muscle cells2. Using a patch clamp, it was also shown to block specifically L-type CaV channel currents in neuronal cells in culture2 with IC50 values of 15-500 nM. Using the outside-out configuration of patch clamp, it was shown to reduce single L-type channel's open probability and availability as recorded from the guinea pig portal vein4.
Calciseptine (#SPC-500) is a highly pure, synthetic, and biologically active peptide toxin.