Linked Life Data

8176734

Source:http://linkedlifedata.com/resource/pubmed/id/8176734

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1994-6-8
pubmed:abstractText
Flash photolysis studies of NO recombination to heme proteins offer a direct probe of protein structural changes on the tens of picoseconds timescale where they can be compared with molecular dynamics simulations. The geminate recombination of NO to site-specific mutants of human myoglobin (Mb) was studied following photodissociation of the MbNO form. Single amino acid changes were introduced at positions Val68, His64, Lys45 and Asp60 because motions of residues at these positions are generally regarded as important for the mechanism of ligand binding. In sharp contrast to the properties of simple porphyrin-NO complexes, the rebinding kinetics are found to be non-exponential for all mutants, even in aqueous solution at 298 K. The Val68 and His64 mutants substantially affect the NO rebinding rates but, surprisingly, so do changes on the protein surface that are further away from the iron. These changes in kinetics occur on a tens of picoseconds timescale, and therefore there is either a fast communication between protein residues over quite long distances or there are subtle differences in protein structure that exert great control over the reaction dynamics. Various models for the rebinding kinetics are evaluated. A model-free approach to data analysis using the maximum entropy method is found to be most useful. This analysis shows that the rate distributions are very different for the mutants, but are generally bimodal.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
238
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
437-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Ultrafast measurements of geminate recombination of NO with site-specific mutants of human myoglobin.
pubmed:affiliation
Laboratoire d'Optique Applique, Ecole Polytechnique ENSTA, INSERM U275, Palaiseau, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't