Linked Life Data

2271642

Source:http://linkedlifedata.com/resource/pubmed/id/2271642

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
43
pubmed:dateCreated
1991-2-22
pubmed:abstractText
Kinetics of the reactions of CO and methyl isocyanide with two diliganded intermediates of hemoglobin, alpha 2CO beta 2 and alpha 2 beta 2CO, have been studied by double-mixing and microperoxidase methods. The valency hybrids were prepared by high-pressure liquid chromatography. The reaction time courses of ligand combination and dissociation with both of the ligands were biphasic, and in CO combination reaction the zero-time amplitudes of the two phases were independent of the protein concentration. In the presence of 2 M urea the reaction time course was clearly dependent on protein concentration, as the zero-time amplitude of the fast phase increased at lower protein concentrations. These two observations indicate that little dissociation of tetramers into dimers occurs in the absence of urea. Consistent with this, the kinetic data for the reactions of CO best fit a reaction model consisting of two tetrameric species not in rapid equilibrium with each other. Various considerations, however, suggest that the reaction model is more appropriately described as 2D in equilibrium R in equilibrium T. The reaction of triliganded species (Hb4(CO)2Me1) with methyl isocyanide was monophasic, and the reaction model suggested a fast T in equilibrium R structural change after the binding of the third ligand. Although the precise structural nature of the two species remains undefined, it is concluded that the biphasicity in the reactions of the two hybrids is characteristic of the diliganded species only and is independent of the nature of the ligand.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10106-13
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Double-mixing kinetic studies of the reactions of methyl isocyanide and CO with diliganded intermediates of hemoglobin: alpha 2CO beta 2 and alpha 2 beta 2CO.
pubmed:affiliation
Department of Medicine, University of California, San Diego, La Jolla 92093.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.