Measuring the length of the pore of the sheep cardiac sarcoplasmic reticulum calcium-release channel using related trimethylammonium ions as molecular calipers

Biophysical Journal
A Tinker, A J Williams

Abstract

After incorporation of purified sheep cardiac Ca(2+)-release channels into planar phospholipid bilayers, we have investigated the blocking effects of a series of monovalent (CH3-(CH2)n-1-N+(CH3)3) and divalent ((CH3)3N(+)-(CH2)n-N+(CH3)3) trimethylammonium derivatives under voltage clamp conditions. All the compounds tested produce voltage-dependent block from the cytoplasmic face of the channel. With divalent (Qn) derivatives the effective valence of block decreases with increasing chain length, reaching a plateau with a chain length of n > or = 7. No decline in effective valence is observed with the monovalent (Un) derivatives. A plausible interpretation of this phenomena suggests that for the 90% of the voltage drop measured, the increase in length following the addition of a CH2 in the chain spans 12.7% of the electrical field. Extrapolating this distance to include the remaining 10% suggests that the applied holding potential falls over a total distance of 10.4 A. In addition, at high positive holding potentials there is evidence for permeation of the trimethylammonium ions and a valency specific relief of block.

Citations

Aug 1, 1996·Pflügers Archiv : European journal of physiology·H VaisP N Usherwood
Jun 1, 1996·Nature Structural Biology·E V OrlovaW Chiu
Feb 1, 1997·The Journal of General Physiology·K E Quinn, B E Ehrlich
Mar 30, 2004·Molecular Biology of the Cell·Christopher H GeorgeF Anthony Lai
Apr 13, 2007·Physiological Reviews·J Kevin FoskettDon-On Daniel Mak
Sep 30, 2004·Biophysical Journal·William WelchAlan J Williams
Sep 5, 2013·Cold Spring Harbor Protocols·Don-On Daniel MakJ Kevin Foskett
Jul 1, 1996·Journal of Cardiovascular Electrophysiology·M RestivoN el-Sherif
Sep 25, 2002·Physiological Reviews·Michael Fill, Julio A Copello
Sep 10, 2003·The Journal of Biological Chemistry·Georgia I AnyatonwuBarbara E Ehrlich
Jan 1, 1997·Progress in Biophysics and Molecular Biology·D R Laver, W G Peter
Mar 28, 2002·Biophysical Journal·Fiona Mead, Alan J Williams

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