Linked Life Data

833133

Source:http://linkedlifedata.com/resource/pubmed/id/833133

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1977-3-15
pubmed:abstractText
Calorimetric heats generated upon mixing solutions of alphaSH and betaSH chains of human hemoglobin have been studied by isothermal heatburst microcalorimetry as a function of mixture composition. Based upon studies described in accompanying papers, the contributions to the measured heats arising from (a) alpha chain self-association, (b) beta chain self-association, (c) association of dimers to form tetramers, have been evaluated. Taking these processes into account, the calorimetric data have been used to determine the enthalpy of formation for alphabeta dimers, yielding a value of -15.71 +/- 0.96 kcal in the fully oxygenated state at 21.5 degrees in 0.1 M Tris/HCl, 0.1 M NaCl, 1 mM Na2EDTA, pH 7.4. The total enthalpy for assembly of a mole of hemoglobin tetramers from oxygenated chains is -27.6 +/- 2.1 kcal. Combining results of this study with independently determined information, limits can be placed upon the magnitude of the enthalpy for dimer formation in unliganded hemoglobin. The total enthalpy for assembly of a mole of unliganded hemoglobin tetramers from unliganded chains is -61.6 +/- 3.5 kcal, or approximately twice the value for oxygenated hemoglobin. This difference lies entirely in the dimer-tetramer stage of assembly. There are essentially no oxygenation-linked thermodynamic quantities (deltaG, deltaH, deltaS) associated with alphabeta dimer formation from isolated chains.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
88-91
pubmed:dateRevised
2009-10-27
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Thermodynamic studies on subunit assembly in human hemoglobin. Calorimetric measurements on the reconstitution of oxyhemoglobin from isolated chains.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.