Linked Life Data

18714968

Source:http://linkedlifedata.com/resource/pubmed/id/18714968

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2008-9-11
pubmed:abstractText
The gas-phase structures of alkali-metal cationized glutamine are investigated by using both infrared multiple photon dissociation (IRMPD) action spectroscopy, utilizing light generated by a free electron laser, and theory. The IRMPD spectra contain many similarities that are most consistent with glutamine adopting nonzwitterionic forms in all ions, but differences in the spectra indicate that the specific nonzwitterionic forms adopted depend on metal-ion identity. For ions containing small alkali metals, the metal ion is solvated predominantly by the amino group, the carbonyl oxygen of the carboxylic acid group, and the carbonyl oxygen of the amide group. With increasing alkali-metal-ion size, additional structures are present in which the carboxylic acid group donates a hydrogen bond to the amino group and the metal ion is solvated only by the amide and carboxylic acid groups. The effects of alkylation of the amino and amide groups on the proton affinity of isolated glutamine and the relative zwitterion stability of sodiated glutamine were examined computationally. Methylation of the amino group increases the proton affinity of isolated glutamine and preferentially stabilizes the zwitterionic form of sodiated glutamine by roughly 20 kJ/mol. Ethylation and isopropylation of the amide group each increase the proton affinity of isolated glutamine by roughly 13 kJ/mol but preferentially stabilize the zwitterionic form of sodiated glutamine by less than 3 kJ/mol. These results indicate that effects of proton affinity on relative zwitterion stability compete with effects of metal-ion solvation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1520-5215
pubmed:author
pubmed:issnType
Electronic
pubmed:day
18
pubmed:volume
112
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8578-84
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Alkali metal ion binding to glutamine and glutamine derivatives investigated by infrared action spectroscopy and theory.
pubmed:affiliation
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't