Linked Life Data

2207085

Source:http://linkedlifedata.com/resource/pubmed/id/2207085

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1990-11-16
pubmed:abstractText
Differential scanning calorimetry (DSC) is unique for studying conformational changes in supramolecular structures because it is immune to interference by the turbidity and other optical artifacts of a sample solution. We have employed DSC to study thermal stability of myosin and actin in their filamentous forms (i.e., thick and thin filaments). The thermal stability of the myosin monomer, as well as polymers, showed remarkable sensitivities to pH and to the ionic strength of the solution. At pH 7.5, the endotherm of myosin filaments was broad and resembled that of the monomer in solution. Reducing the pH to 6.3 split the endotherm of the filament into two major transitions. The first one, with a Tm of 47 degrees C, a delta Hcal of 805 kcal/mol, and a cooperative ratio (CR) of 0.1, was relatively insensitive to the pH changes whereas the second one which represented approximately 80% of the helical structure was pH sensitive. The second transition released 2.17 H+ per mole at 0.17 M KCl and was defined by a Tm of 53.9 degrees C, a delta Hcal of 917 kcal/mol, and a CR of 0.35. The major fragment contributing to the splitting of the endotherm was interpreted to be S-2 because the Tm of purified S-2 in a similar medium also shifted from 39.5 degrees C at pH 7.3 to 49.6 degrees C at pH 6.0. KCl had similar effects on the shape of the endotherm of the thick filament. A decrease of KCl from 0.2 to 0.1 M enhanced the effect of pH on the second transition.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6447-52
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Effects of ions and pH on the thermal stability of thin and thick filaments of skeletal muscle: high-sensitivity differential scanning calorimetric study.
pubmed:affiliation
Department of Biochemistry, University of Minnesota College of Biological Sciences, St. Paul 55108.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.