Linked Life Data

2271647

Source:http://linkedlifedata.com/resource/pubmed/id/2271647

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
1991-2-27
pubmed:abstractText
The bimolecular association reaction of carbon monoxide to human adult hemoglobin at pH 7, 20 degrees C, was examined as a function of pressure up to 1500 bar by means of high-pressure laser photolysis. The apparent quantum yield for a millisecond recombination reaction decreased with pressure, which was attributed to an increase in the fraction of nanosecond geminate recombination reaction. On the basis of the pressure dependence of the recombination rate, the activation volumes at normal pressure for the binding of carbon monoxide to the R- and T-state hemoglobins were determined as -9.0 +/- 0.7 and -31.7 +/- 2.4 cm3 mol-1, respectively. Since the activation volumes for the overall CO association reaction were negative, it seems that the iron-ligand bond formation process mainly contributes to the rate-limiting step for both quaternary structures. The characteristic pressure dependence of the activation volume was observed for the R-state Hb but not for the T-state Hb. At 1000 bar, the activation volume for the R-state Hb was reduced to nearly zero, probably resulting from the contribution of the ligand migration process to the rate-limiting step. The effect of pressure on the activation enthalpy and entropy was also extracted from the data.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10199-205
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
High-pressure laser photolysis study of hemoproteins. Effects of pressure on carbon monoxide binding dynamics for R- and T-state hemoglobins.
pubmed:affiliation
Division of Molecular Engineering, Graduate School of Engineering, Kyoto University, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't