Linked Life Data

14531688

Source:http://linkedlifedata.com/resource/pubmed/id/14531688

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
2003-10-8
pubmed:abstractText
We report the synthesis and characterization of Ru-diimine complexes designed to bind to cytochrome p450cam (CYP101). The sensitizer core has the structure [Ru(L(2))L'](2+), where L' is a perfluorinated biphenyl bridge (F(8)bp) connecting 4,4'-dimethylbipyridine to an enzyme substrate (adamantane, F(8)bp-Ad), a heme ligand (imidazole, F(8)bp-Im), or F (F(9)bp). The electron-transfer (ET) driving force (-deltaG degrees ) is varied by replacing the ancillary 2,2'-bipyridine ligands with 4,4',5,5'-tetramethylbipyridine (tmRu). The four complexes all bind p450cam tightly: Ru-F(8)bp-Ad (1, K(d) = 0.077 microM); Ru-F(8)bp-Im (2, K(d) = 3.7 microM); tmRu-F(9)bp (3, K(d) = 2.1 microM); and tmRu-F(8)bp-Im (4, K(d) = 0.48 microM). Binding is predominantly driven by hydrophobic interactions between the Ru-diimine wires and the substrate access channel. With Ru-F(8)bp wires, redox reactions can be triggered on the nanosecond time scale. Ru-wire 2, which ligates the heme iron, shows a small amount of transient heme photoreduction (ca. 30%), whereas the transient photoreduction yield for 4 is 76%. Forward ET with 4 occurs in roughly 40 ns (k(f) = 2.8 x 10(7) s(-)(1)), and back ET (Fe(II) --> Ru(III), k(b) approximately 1.7 x 10(8) s(-)(1)) is near the coupling-limited rate (k(max)). Direct photoreduction was not observed for 1 or 3. The large variation in ET rates among the Ru-diimine:p450 conjugates strongly supports a through-bond model of Ru-heme electronic coupling.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
125
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12450-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Nanosecond photoreduction of cytochrome p450cam by channel-specific Ru-diimine electron tunneling wires.
pubmed:affiliation
Beckman Institute, California Institute of Technology, Pasadena, California 91125, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't