Linked Life Data

21391540

Source:http://linkedlifedata.com/resource/pubmed/id/21391540

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2011-5-5
pubmed:abstractText
Vibrational coherence spectroscopy (VCS) is used to investigate the low-frequency dynamics of camphor-free and camphor-bound cytochrome P450(cam) (CYP 101) and its L358P mutant. The low-frequency heme vibrations are found to be perturbed upon binding to the electron transfer partner putidaredoxin (Pdx). A strong correlation between the "detuned" vibrational coherence spectrum, which monitors frequencies between 100 and 400 cm(-1), and the lower frequency part of the Raman spectrum is also demonstrated. The very low frequency region ?200 cm(-1), uniquely accessed by open-band VCS measurements, reveals a mode near 103 cm(-1) in P450(cam) when camphor is not present in the distal pocket. This reflects the presence of a specific heme distortion, such as saddling or ruffling, in the substrate-free state where water is coordinated to the low-spin iron atom. Such distortions are likely to retard the rate of electron transfer to the substrate-free protein. The presence of strong mode near ?33 cm(-1) in the camphor-bound form suggests a significant heme-doming distortion, which is supported by analysis using normal coordinate structural decomposition. Pdx also displays a strong coherent vibration near 30 cm(-1) that in principle could be involved in vibrational resonance with its electron transfer target. A splitting of the 33 cm(-1) feature and intensification of a mode near 78 cm(-1) appear when the P450(cam)/Pdx complex is formed. These observations are consistent with vibrational mixing and heme geometric distortions upon Pdx binding that are coincident with the increased thiolate electron donation to the heme. The appearance of a mode near 65 cm(-1) in the coherence spectra of the L358P mutant is comparable to the mode at 78 cm(-1) seen in the P450(cam)/Pdx complex and is consistent with the view that the heme and its environment in the L358P mutant are similar to the Pdx-bound native protein. Resonance Raman spectra are presented for both P450(cam) and the L358P mutant and the changes are correlated with an increased amount of thiolate electron donation to the heme in the mutant sample.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1520-5207
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5665-77
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Investigation of the low frequency dynamics of heme proteins: native and mutant cytochrome P450(cam) and redox partner complexes.
pubmed:affiliation
Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural