Linked Life Data

19685884

Source:http://linkedlifedata.com/resource/pubmed/id/19685884

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2009-9-3
pubmed:abstractText
We demonstrate that the steady state reaction of lysine 5,6-aminomutase with substrate analogue 4-thia-l-lysine generates a radical intermediate, which accumulates in the enzyme to an electron paramagnetic resonance (EPR) detectable level. EPR line width narrowing of approximately 1 mT due to [4'-(2)H] labeling of the pyridoxal-5'-phosphate (PLP), an isotropic hyperfine coupling of 40 MHz for the proton at C4' of PLP derived from (2)H electron nuclear double resonance (ENDOR) measurement, and spin density delocalization onto the (31)P of PLP realized from observations of the (31)P ENDOR signal provide unequivocal identification of the radical as a substrate-PLP-based species. X- and Q-band EPR spectra fittings demonstrate that this radical is spin coupled with the low spin Co(2+) in cob (II) alamin and the distance between the two species is about 10 A. These results provide direct evidence for the active site motion upon substrate binding, bringing the adenosylcobalamin to the proximity of substrate-PLP for subsequent H-atom abstraction and for the notion that lysine 5,6-aminomutase functions by a radical mechanism. Observation of (2)H-ENDOR signal also provides a reliable hyperfine coupling constant for future comparison with quantum-mechanical-based calculations to gain further insight into the molecular structure of this steady state radical intermediate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12161-3
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Evidence for conformational movement and radical mechanism in the reaction of 4-thia-L-lysine with lysine 5,6-aminomutase.
pubmed:publicationType
Letter, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural