Linked Life Data

20837775

Source:http://linkedlifedata.com/resource/pubmed/id/20837775

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-1-5
pubmed:abstractText
Formation of the strong binding interaction between actin and myosin is essential for force generation in muscle and in cytoskeletal motor systems. To clarify the role of the closure of myosin's actin-binding cleft in the actomyosin interaction, we performed rapid kinetic, spectroscopic, and calorimetric experiments and atomic-level energetic calculations on a variety of myosin isoforms for which atomic structures are available. Surprisingly, we found that the endothermic actin-binding profile of vertebrate skeletal muscle myosin subfragment-1 is unique among studied myosins. We show that the diverse propensity of myosins for cleft closure determines different energetic profiles as well as structural and kinetic pathways of actin binding. Depending on the type of myosin, strong actin binding may occur via induced-fit or conformational preselection mechanisms. However, cleft closure does not directly determine the kinetics and affinity of actin binding. We also show that cleft closure is enthalpically unfavorable, reflecting the development of an internal strain within myosin in order to adopt precise steric complementarity to the actin filament. We propose that cleft closure leads to an increase in the torsional strain of myosin's central ?-sheet that has been proposed to serve as an allosteric energy-transducing spring during force generation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
111-21
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Myosin cleft closure determines the energetics of the actomyosin interaction.
pubmed:affiliation
Department of Biochemistry, Eötvös University, Pázmány Péter sétány 1/c, H-1117 Budapest, Hungary.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural