The dissociation of 1-N6-ethenoadenosine diphosphate from regulated actomyosin subfragment 1.

Steven Rosenfeld, E. W. Taylor

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The effective rate of dissociation of 1-N6-ethenoadenosine diphosphate (epsilon ADP) from the regulated actin X subfragment 1 X epsilon ADP complex of rabbit skeletal muscle is approximately 10-15 times smaller in the absence of calcium ion compared to the presence of calcium ion. The decrease in fluorescence emission with dissociation of the bound epsilon ADP fitted two exponential terms. The evidence is consistent with a kinetic scheme in which two first-order transitions precede the dissociation step: (Formula: see text) where D is epsilon ADP, A is regulated actin, M is subfragment 1, the asterisks refer to the degree of fluorescence enhancement, and AM(D) is a collision complex in equilibrium with free epsilon ADP. Both rate constants k-2 and k-1 were reduced approximately 15-fold in the absence of calcium ion. The rate constants for the dissociation of epsilon ATP, epsilon ADP X Pi, formed in the enzyme cycle, and epsilon ADP are all reduced in the absence of calcium ion; consequently, the primary effect in calcium regulation of the actin-subfragment 1 ATPase is on the rate constant of a transition (or transitions) between actomyosin-nucleoside phosphate complexes.

Original languageEnglish (US)
Pages (from-to)9994-9999
Number of pages6
JournalJournal of Biological Chemistry
Volume262
Issue number21
StatePublished - Jul 25 1987
Externally publishedYes

Fingerprint

Myosin Subfragments
Calcium
Ions
Rate constants
Ethenoadenosine Triphosphate
Actins
Fluorescence
Actomyosin
1,N(6)-ethenoadenosine diphosphate
Nucleosides
Adenosine Triphosphatases
Muscle
Skeletal Muscle
Phosphates
Rabbits
Kinetics

ASJC Scopus subject areas

  • Biochemistry

Cite this

The dissociation of 1-N6-ethenoadenosine diphosphate from regulated actomyosin subfragment 1. / Rosenfeld, Steven; Taylor, E. W.

In: Journal of Biological Chemistry, Vol. 262, No. 21, 25.07.1987, p. 9994-9999.

Research output: Contribution to journalArticle

@article{810c1f1afe1147ecb2a8007d8d0f14c5,
title = "The dissociation of 1-N6-ethenoadenosine diphosphate from regulated actomyosin subfragment 1.",
abstract = "The effective rate of dissociation of 1-N6-ethenoadenosine diphosphate (epsilon ADP) from the regulated actin X subfragment 1 X epsilon ADP complex of rabbit skeletal muscle is approximately 10-15 times smaller in the absence of calcium ion compared to the presence of calcium ion. The decrease in fluorescence emission with dissociation of the bound epsilon ADP fitted two exponential terms. The evidence is consistent with a kinetic scheme in which two first-order transitions precede the dissociation step: (Formula: see text) where D is epsilon ADP, A is regulated actin, M is subfragment 1, the asterisks refer to the degree of fluorescence enhancement, and AM(D) is a collision complex in equilibrium with free epsilon ADP. Both rate constants k-2 and k-1 were reduced approximately 15-fold in the absence of calcium ion. The rate constants for the dissociation of epsilon ATP, epsilon ADP X Pi, formed in the enzyme cycle, and epsilon ADP are all reduced in the absence of calcium ion; consequently, the primary effect in calcium regulation of the actin-subfragment 1 ATPase is on the rate constant of a transition (or transitions) between actomyosin-nucleoside phosphate complexes.",
author = "Steven Rosenfeld and Taylor, {E. W.}",
year = "1987",
month = "7",
day = "25",
language = "English (US)",
volume = "262",
pages = "9994--9999",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "21",

}

TY - JOUR

T1 - The dissociation of 1-N6-ethenoadenosine diphosphate from regulated actomyosin subfragment 1.

AU - Rosenfeld, Steven

AU - Taylor, E. W.

PY - 1987/7/25

Y1 - 1987/7/25

N2 - The effective rate of dissociation of 1-N6-ethenoadenosine diphosphate (epsilon ADP) from the regulated actin X subfragment 1 X epsilon ADP complex of rabbit skeletal muscle is approximately 10-15 times smaller in the absence of calcium ion compared to the presence of calcium ion. The decrease in fluorescence emission with dissociation of the bound epsilon ADP fitted two exponential terms. The evidence is consistent with a kinetic scheme in which two first-order transitions precede the dissociation step: (Formula: see text) where D is epsilon ADP, A is regulated actin, M is subfragment 1, the asterisks refer to the degree of fluorescence enhancement, and AM(D) is a collision complex in equilibrium with free epsilon ADP. Both rate constants k-2 and k-1 were reduced approximately 15-fold in the absence of calcium ion. The rate constants for the dissociation of epsilon ATP, epsilon ADP X Pi, formed in the enzyme cycle, and epsilon ADP are all reduced in the absence of calcium ion; consequently, the primary effect in calcium regulation of the actin-subfragment 1 ATPase is on the rate constant of a transition (or transitions) between actomyosin-nucleoside phosphate complexes.

AB - The effective rate of dissociation of 1-N6-ethenoadenosine diphosphate (epsilon ADP) from the regulated actin X subfragment 1 X epsilon ADP complex of rabbit skeletal muscle is approximately 10-15 times smaller in the absence of calcium ion compared to the presence of calcium ion. The decrease in fluorescence emission with dissociation of the bound epsilon ADP fitted two exponential terms. The evidence is consistent with a kinetic scheme in which two first-order transitions precede the dissociation step: (Formula: see text) where D is epsilon ADP, A is regulated actin, M is subfragment 1, the asterisks refer to the degree of fluorescence enhancement, and AM(D) is a collision complex in equilibrium with free epsilon ADP. Both rate constants k-2 and k-1 were reduced approximately 15-fold in the absence of calcium ion. The rate constants for the dissociation of epsilon ATP, epsilon ADP X Pi, formed in the enzyme cycle, and epsilon ADP are all reduced in the absence of calcium ion; consequently, the primary effect in calcium regulation of the actin-subfragment 1 ATPase is on the rate constant of a transition (or transitions) between actomyosin-nucleoside phosphate complexes.

UR - http://www.scopus.com/inward/record.url?scp=0023664661&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023664661&partnerID=8YFLogxK

M3 - Article

C2 - 3611074

AN - SCOPUS:0023664661

VL - 262

SP - 9994

EP - 9999

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 21

ER -