Linked Life Data

15170339

Source:http://linkedlifedata.com/resource/pubmed/id/15170339

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2004-6-1
pubmed:abstractText
We use laser flash photolysis and time-resolved Raman spectroscopy of CO-bound heme complexes to study proximal and distal influences on ligand rebinding kinetics. We report kinetics of CO rebinding to microperoxidase (MP) and 2-methylimidazole ligated Fe protoporphyrin IX in the 10 ns to 10 ms time window. We also report CO rebinding kinetics of MP in the 150 fs to 140 ps time window. For dilute, micelle-encapsulated (monodisperse) samples of MP, we do not observe the large amplitude geminate decay at approximately 100 ps previously reported in time-resolved IR measurements on highly concentrated samples [Lim, M., Jackson, T. A., and Anfinrud, P. A. (1997) J. Biol. Inorg. Chem. 2, 531-536]. However, for high concentration aggregated samples, we do observe the large amplitude picosecond CO geminate rebinding and find that it is correlated with the absence of the iron-histidine vibrational mode in the time-resolved Raman spectrum. On the basis of these results, the energetic significance of a putative distal pocket CO docking site proposed by Lim et al. may need to be reconsidered. Finally, when high concentration samples of native myoglobin (Mb) were studied as a control, an analogous increase in the geminate rebinding kinetics was not observed. This verifies that studies of Mb under dilute conditions are applicable to the more concentrated regime found in the cellular milieu.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7017-27
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Proximal and distal influences on ligand binding kinetics in microperoxidase and heme model compounds.
pubmed:affiliation
Department of Physics and Center for Interdisciplinary Research on Complex System, Northeastern University, Boston, Massachusetts 02115, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.