Abstract
In Mead and Williams, (Biophys. J. 82:1953-1963, 2002) we have reported that neomycin is a potent partial blocker of single purified sheep cardiac SR calcium release channels. Neomycin is unusual in that it is capable of blocking when applied to either the cytosolic or the luminal face of the channel. Block at either aspect of the channel is both concentration- and voltage-dependent, but exhibits different blocking parameters. In this study we have investigated the actions of neomycin on ion handling in the ryanodine-modified channel. Neomycin is more effective at the cytosolic face, having a Kb(0) value of 534.9 +/- 35.17 nM compared with a Kb(0) value of 971.5 +/- 66.62 nM for the luminal face. The voltage dependence also differs at the two sites. Values of zdelta for cytosolic and luminal neomycin are 1.09 +/- 0.04 and -0.57 +/- 0.03, respectively. The interaction of neomycin with the ryanodine-modified channel differs notably from that in the unmodified channel. Voltage-dependent relief of block is not observed after ryanodine modification, and the luminal blocking characteristics are altered. This suggests that ryanodine induces changes at the luminal mouth of the channel and may confer increased rigidity to the channel pr...Continue Reading
References
May 1, 1992·Biophysical Journal·A TinkerA J Williams
Jun 1, 1973·The Journal of General Physiology·A M Woodhull
Sep 1, 1994·The Journal of General Physiology·A R LindsayA J Williams
Aug 1, 1993·Biophysical Journal·A Tinker, A J Williams
Oct 1, 1993·Biophysical Journal·A Tinker, A J Williams
Feb 1, 1993·The Journal of General Physiology·L XuG Meissner
Apr 5, 1996·The Journal of Biological Chemistry·J P WangS L Hamilton
Mar 1, 1996·Biophysical Journal·R G TsushimaJ A Wasserstrom
Mar 1, 1996·The Journal of General Physiology·C M HawsJ B Lansman
Jul 3, 1998·The Journal of General Physiology·B TannaA J Williams
Jun 29, 2000·The Journal of General Physiology·B TannaA J Williams
May 2, 2001·The Journal of General Physiology·B TannaA J Williams
Jun 5, 2001·Quarterly Reviews of Biophysics·A J WilliamsR Sitsapesan
Mar 28, 2002·Biophysical Journal·Fiona Mead, Alan J Williams
Citations
Sep 20, 2007·The Journal of Membrane Biology·Derek R LaverNoriaki Ikemoto
Mar 28, 2002·Biophysical Journal·Fiona Mead, Alan J Williams
Oct 18, 2005·Biochemical and Biophysical Research Communications·Nicholas PughAlan J Williams
Oct 22, 2005·Biophysical Journal·Le XuGerhard Meissner
Sep 14, 2004·Biophysical Journal·Fiona C Mead, Alan J Williams
Jul 9, 2014·Molecular Pharmacology·Saptarshi MukherjeeAlan J Williams
Feb 28, 2019·The Journal of General Physiology·Christopher Solís, Brenda Russell
May 16, 2017·Frontiers in Cellular Neuroscience·Paromita MajumderJonathan E Gale
Jun 24, 2020·Insects·Kemal BüyükgüzelZbigniew Adamski