Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
39
pubmed:dateCreated
1997-10-23
pubmed:abstractText
Geminate oxygen rebinding to myoglobin was followed from a few nanoseconds to a few microseconds after photolysis for more than 25 different oxymyoglobin point mutants in the presence and absence of 12 atm of xenon. In all cases, two relaxations were observed: an initial fast phase (half-time 20 ns) and a slower, smaller phase (half-time 0.5-2 micros). Generally, xenon accelerates the fast reaction but slows the slower reaction and diminishes its amplitude. The rates and proportions of the two components and the effects of xenon on them vary widely for different mutants. The locations of specific xenon binding sites [Tilton, R. F., Kuntz, I. D. Jr., and Petsko, G. A. (1984) Biochemistry 23, 2849-2857], the effects of point mutations on the geminate reactions, and molecular dynamics simulations were used to suggest locations in the protein interior occupied by ligands on the nanosecond to microsecond time scale. Photodissociated ligands may occupy xenon site 4 in the distal pocket and xenon site 1 below the plane of the heme. Rebinding from these positions corresponds to the slower geminate phase for O2 rebinding. The rapid geminate component is determined by competition between rebinding from a position closer to the iron atom and escape to solvent or more distant locations in the protein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11909-17
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Ligand migration in sperm whale myoglobin.
pubmed:affiliation
Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street, Houston, Texas 77005, USA. yertle@bioc.rice.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.