Linked Life Data

7896745

Source:http://linkedlifedata.com/resource/pubmed/id/7896745

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1995-4-26
pubmed:abstractText
Photolyzed products of the NO complexes of ferric cytochrome P450cam both in the substrate-free and several substrate-bound states were trapped and examined by EPR spectroscopy at 5 K. In the absence of substrate, the photoproduct exhibited ferric high- and low-spin signals, neither of which showed the line-width broadening characteristic of magnetic interaction between photodissociated NO and the heme iron. This finding indicates that photodissociated NO can diffuse to the unconstrained distal heme pocket giving the high-spin heme, and that a part of the high-spin heme species converts to the low-spin heme upon coordinating an aqua molecule. When a substrate, camphor or adamantanone, was bound at the site above the heme, the photoproduct exhibited widespread EPR absorptions together with a new distinct signal at g approximately 4.4. The new signals are assignable to a weakly spin-coupled species between the ferric heme iron and the photodissociated NO, indicating that the NO molecule is in close proximity to the heme iron by the steric crowding of the bound substrate. The photoproduct of the norcamphor complex exhibited a spin-coupled EPR signal at g approximately 5, in which the coupling is suggested to be weaker than that of the camphor-bound enzyme. On the other hand, the photoproduct of the NO complex in an adamantane-bound state only yielded low-spin signals, and exhibited no spin-coupled signals. This result suggests that adamantane is mobile in the substrate pocket due to the lack of hydrogen bond formation with Tyr96.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
116
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1146-52
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
EPR studies on the photoproducts of ferric cytochrome P450cam (CYP101) nitrosyl complexes: effects of camphor and its analogues on ligand-bound structures.
pubmed:affiliation
Department of Biophysical Engineering, Faculty of Engineering Science, Osaka University.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't