Linked Life Data

10090758

Source:http://linkedlifedata.com/resource/pubmed/id/10090758

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1999-4-19
pubmed:abstractText
Recently, we used 35 GHz pulsed 15N ENDOR spectroscopy to determine the position of the reactive guanidino nitrogen of substrate L-arginine relative to the high-spin ferriheme iron of holo-neuronal nitric oxide synthase (nNOS) [Tierney, D. L., et al. (1998) J. Am. Chem. Soc. 120, 2983-2984]. Analogous studies of the enzyme-bound reaction intermediate, NG-hydroxy-L-arginine (NOHA), singly labeled with 15N at the hydroxylated nitrogen (denoted NR), show that NR is held 3.8 A from the Fe, closer than the corresponding guanidino N of L-Arg (4.05 A). 1,2H ENDOR of NOHA bound to holo-nNOS in H2O and D2O discloses the presence of a single resolved exchangeable proton (H1) 4.8 A from Fe and very near the heme normal. The ENDOR data indicate that NOHA does not bind as the resonance-stabilized cation in which the terminal nitrogens share a positive charge. ENDOR-determined structural constraints permit two alternate structural models for the interaction of NOHA with the high-spin heme iron. In one model, H1 is assigned to the O-H proton; in the other, it is the NR-H proton. However, the alternatives differ in the placement of the N-O bond relative to the heme iron. Thus, a combination of the ENDOR data with appropriate diffraction studies can achieve a definitive determination of the protonation state of NR and thus of the tautomeric form that is present in the enzyme-NOHA complex. The mechanistic implications of this result are further discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3704-10
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
ENDOR spectroscopic evidence for the position and structure of NG-hydroxy-L-arginine bound to holo-neuronal nitric oxide synthase.
pubmed:affiliation
Department of Chemistry and Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3113, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't