HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schilling, W. P. Articles by Drewe, J. A. Search for Related Content PubMed PubMed Citation Articles by Schilling, W. P. Articles by Drewe, J. A. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 261, Issue 6, 2750-2758, 02, 1986

Voltage-sensitive nitrendipine binding in an isolated cardiac sarcolemma preparation

WP Schilling and JA Drewe

Nitrendipine binding has been evaluated in a highly enriched sarcolemma preparation isolated from canine ventricle. The binding was found to be specific, saturable, rapid, and reversible. The dissociation constant (Kd) determined by equilibrium binding studies at 20 degrees C was 0.0880 nM. The Kd increased to 0.670 nM at 37 degrees C. The maximal binding capacity of this preparation ranged from 437 to 1775 fmol/mg protein and was not significantly affected by changes in temperature between 20 and 37 degrees C. The Kd, determined kinetically from the ratio of the dissociation and association rate constants (k-1/k1), was 0.112 and 0.285 nM at 20 and 37 degrees C, respectively. In order to test the hypothesis that nitrendipine binding changes with membrane potential potassium, Nernst potentials were developed, in the presence of valinomycin, by the establishment of potassium gradients across the vesicular membrane. Evaluation of the rates of dissociation of [3H]nitrendipine from the sarcolemma preparation identified a component of binding that was rapidly lost when the transmembrane potential was polarized to inside-negative values. The magnitude of the loss of nitrendipine binding was 25-27% at the most negative potentials examined. Evaluation of the rate of association of nitrendipine revealed that the component of binding that was rapidly lost upon hyperpolarization of the membrane returned over a time course similar to the rate of dissipation of the membrane potential, suggesting that the effects of potential on nitrendipine binding are reversible. These findings are consistent with the hypothesis that nitrendipine binding affinity changes with membrane potential.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				R. Miller Multiple calcium channels and neuronal function Science, January 2, 1987; 235(4784): 46 - 52. [Abstract] [PDF]