The interaction of an impermeant cation with the sheep cardiac RyR channel alters ryanoid association.

The Interaction of an impermeant cation with the sheep Cardiac RyR Channel Alters

An Anionic Ryanoid, 10-O-succinoylryanodol, Provides Insights into the Mechanisms Governing the Interaction of Ryanoids and the Subsequent Altered Function of Ryanodine-receptor Channels

We have investigated the interactions of a novel anionic ryanoid, 10-O-succinoylryanodol, with individual mammalian cardiac muscle ryanodine receptor channels under voltage clamp conditions. As is the case for all ryanoids so far examined, the interaction of 10-O-succinoylryanodol with an individual RyR channel produces profound alterations in both channel gating and rates of ion translocation....

The Interaction of a Neutral Ryanoid with the Ryanodine Receptor Channel Provides Insights into the Mechanisms by Which Ryanoid Binding Is Modulated by Voltage

In an earlier investigation, we demonstrated that the likelihood of interaction of a positively charged ryanoid, 21-amino-9alpha-hydroxyryanodine, with the sarcoplasmic reticulum Ca(2+)-release channel (ryanodine receptor, RyR) is dependent on holding potential (Tanna, B., W. Welch, L. Ruest, J.L. Sutko, and A. J. Williams. 1998. J. Gen. Physiol. 112:55-69) and suggested that voltage dependence...

Ryanoid Modification of the Cardiac Muscle Ryanodine Receptor Channel Results in Relocation of the Tetraethylammonium Binding Site

The interaction of ryanodine and derivatives of ryanodine with the high affinity binding site on the ryanodine receptor (RyR) channel brings about a characteristic modification of channel function. In all cases, channel open probability increases dramatically and single-channel current amplitude is reduced. The amplitude of the ryanoid-modified conductance state is determined by structural feat...

Interactions of a Reversible Ryanoid (21-Amino-9α-Hydroxy-Ryanodine) with Single Sheep Cardiac Ryanodine Receptor Channels

The binding of ryanodine to a high affinity site on the sarcoplasmic reticulum Ca2+-release channel results in a dramatic alteration in both gating and ion handling; the channel enters a high open probability, reduced-conductance state. Once bound, ryanodine does not dissociate from its site within the time frame of a single channel experiment. In this report, we describe the interactions of a ...