Linked Life Data

3000419

Source:http://linkedlifedata.com/resource/pubmed/id/3000419

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1986-2-6
pubmed:abstractText
Reduced cyanide-bound cytochrome oxidase in the absence of any oxygen gives a resonance Raman spectrum consistent with that expected for low-spin heme a. Thus, in contrast to prior reports, ligand binding of cytochrome a3 to form a six-coordinate low-spin ferrous heme does not result in any unusual electronic structure, hydrogen bonding, environment, or conformation of the formyl group. It appears unlikely that there are any changes in this group in cytochrome a3 that control the ligand affinity or redox potential in physiological forms of the ferrous enzyme. With the use of our difference spectrometer and by appropriately selecting the laser excitation frequency, we are able to isolate spectrally cytochromes a2+, a3(2+), and a3(2+)(CN-). The addition of a small amount of oxygen to a preparation of the cyanide-bound reduced enzyme results in a complex with the same Raman spectrum as that previously reported to originate from the cyanide-bound reduced complex. Any oxygen present in the sample leads to enzyme turnover resulting in a mixed valence state [a2+a3(3+)(CN-)]. The comparison between the data on the cyanide-bound reduced enzyme and the data on the CO-bound reduced enzyme illustrates that cyanide binding affects only the modes that respond to the spin state of the ferrous iron, while CO binding affects vibrational modes that respond to a pi-electron density change as well.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4938-46
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Resonance raman spectra of CN--bound cytochrome oxidase: spectral isolation of cytochromes a2+, a3(2+), and a3(2+)(CN-).
pubmed:publicationType
Journal Article