Linked Life Data

20923650

Source:http://linkedlifedata.com/resource/pubmed/id/20923650

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2010-10-6
pubmed:abstractText
Fluorescence lifetime imaging microscopy is used to demonstrate that different loads applied to a muscle fiber change the microenvironment of the nucleotide binding pocket of myosin. Permeabilized skeletal muscle fibers in rigor were labeled with a fluorescent ATP analog, 3'-DEAC-propylenediamine (pda)-ATP (3'-O-{N-[3-(7-diethylaminocoumarin-3-carboxamido)propyl]carbamoyl}ATP), which was hydrolyzed to the diphosphate. Cycles of small-amplitude stretches and releases (<1% of muscle segment length) were synchronized with fluorescence lifetime imaging and force measurements to correlate the effect of force on the lifetime of the ATP analog bound to the actomyosin complex. Analysis of the fluorescence decay resolved two lifetimes, corresponding to the free nucleotide DEAC-pda-ATP (?(1) = 0.47 ± 0.03 ns; mean ± SD) and nucleotide bound to the actomyosin complex (?(2) = 2.21 ± 0.06 ns at low strain). Whereas ?(1) did not change with force, ?(2) showed a linear dependence with the force applied to the muscle of 0.43 ± 0.05 ps/kPa. Hence, the molecular environment of the nucleotide binding pocket of myosin is directly affected by a change of length applied at the ends of the fiber segments. These changes may help explain how force modulates the actomyosin ATPase cycle and thus the physiology and energetics of contraction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1542-0086
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
6
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2163-9
pubmed:dateRevised
2011-10-6
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Fluorescence lifetime imaging reveals that the environment of the ATP binding site of myosin in muscle senses force.
pubmed:affiliation
National Heart and Lung Institute, Imperial College London, London, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't