Linked Life Data

127882

Source:http://linkedlifedata.com/resource/pubmed/id/127882

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-2-9
pubmed:abstractText
Evidence for a proposed activation mechanism is summarized. The low rate of ATP cleavage in the resting state of muscle is considered to result from the formation of a stable ring structure involving the two essential sulfhydryl groups on each myosin head and MgATP. Activation is thought to occur by interaction of actin in the vicinity of one of the essential sulfhydryl groups. Thus opening the stable ring leading to rapid dissociation of split products. This idea is consistent with the kinetic scheme of ATP cleavage developed recently by other workers and allows a prediction of the shift in population of intermediate states with changes in solvent conditions. It is also supported by our recent studies on the spatial geometry of the ring. The possibility that other nucleophilic groups may replace the sulfhydryl groups in other contractile systems is considered. The relevance of the ring structure to the tension generating event is discussed on the basis of recent measurements of the rate of contraction of modified (SH1-blocked) actomyosin threads. Results indicate the ability to form the ring structure is an essential requirement of the contractile process in these systems, and, moreover, that single, modified heads of myosin can act independently to produce the same rate of contraction as native myosin. This latter finding suggests that the myosin duplex exhibits some type of negative cooperativity in the contractile process.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0091-7419
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
112-24
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
An activation mechanism for ATP cleavage in muscle.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Review