Linked Life Data

20889975

Source:http://linkedlifedata.com/resource/pubmed/id/20889975

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
50
pubmed:dateCreated
2010-12-6
pubmed:abstractText
Troponin is a pivotal regulatory protein that binds Ca(2+) reversibly to act as the muscle contraction on-off switch. To understand troponin function, the dynamic behavior of the Ca(2+)-saturated cardiac troponin core domain was mapped in detail at 10 °C, using H/D exchange-mass spectrometry. The low temperature conditions of the present study greatly enhanced the dynamic map compared with previous work. Approximately 70% of assessable peptide bond hydrogens were protected from exchange sufficiently for dynamic measurement. This allowed the first characterization by this method of many regions of regulatory importance. Most of the TnI COOH terminus was protected from H/D exchange, implying an intrinsically folded structure. This region is critical to the troponin inhibitory function and has been implicated in thin filament activation. Other new findings include unprotected behavior, suggesting high mobility, for the residues linking the two domains of TnC, as well as for the inhibitory peptide residues preceding the TnI switch helix. These data indicate that, in solution, the regulatory subdomain of cardiac troponin is mobile relative to the remainder of troponin. Relatively dynamic properties were observed for the interacting TnI switch helix and TnC NH(2)-domain, contrasting with stable, highly protected properties for the interacting TnI helix 1 and TnC COOH-domain. Overall, exchange protection via protein folding was relatively weak or for a majority of peptide bond hydrogens. Several regions of TnT and TnI were unfolded even at low temperature, suggesting intrinsic disorder. Finally, change in temperature prominently altered local folding stability, suggesting that troponin is an unusually mobile protein under physiological conditions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
38978-86
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Low temperature dynamic mapping reveals unexpected order and disorder in troponin.
pubmed:affiliation
Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural