. Author manuscript; available in PMC: 2019 Jul 31.

Published in final edited form as: Sci Signal. 2014 May 20;7(326):ra46. doi: 10.1126/scisignal.2004854

Table 1. Basic biophysical properties of TPC1.

When K⁺ or Na⁺ was permeant ion, the cytosolic and luminal chambers contained symmetrical solutions of either 210 mM KCl or 210 mM NaCl. When Ca²⁺ was permeant ion, Tris/HEPES: Ca²⁺glutamate solutions were used (full details of solutions described in Materials and Methods). The holding potential is shown in mV. For measurements of Po in which NAADP was the sole activating ligand, 10 mM EGTA was first added to the cytosolic chamber to lower the [Ca²⁺] to subactivating concentrations prior to the addition of 100 nM NAADP. Values are mean ± SEM.

Permeant ion	Single-channel conductance (pS)	n	10 μM cytosolic Ca²⁺ as activating ligand			100 nM NAADP as activating ligand
Permeant ion	Single-channel conductance (pS)	n	Po	mV	n	Po	mV	n
K⁺	87 ± 3	4	0.26± 0.06	20	5	0.17± 0.04	20	5
Na⁺	68 ± 3	5	0.05± 0.01	30	8	0.08± 0.006	30	4
Ca²⁺	19 ± 2	3	0.1± 0.08	-60	3	-