Linked Life Data

1899863

Source:http://linkedlifedata.com/resource/pubmed/id/1899863

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1991-3-27
pubmed:abstractText
19F and 31P NMR spectroscopy was used to study the mechanism of activation of the alpha subunits of guanine nucleotide-binding regulatory proteins (G proteins) by Al3+, Mg2+, and F-. 19F NMR spectra of solutions containing Al3+, Mg2+, and F- showed a characteristic F- peak at -10 ppm. Addition of the GDP-bound form of either of two G protein alpha subunits (G alpha) resulted in the appearance of an additional peak at -29 or -30 ppm. This peak was not observed with guanosine 5'-3-O-(thio)triphosphate-G alpha or with GDP alone. Titration of Al3+, Mg2+, and F- indicated that each molecule of G alpha binds 3-5 molecules of F- (Kd = 0.47 mM), a single molecule of Al3+ (Kd much less than 0.1 mM), and a single Mg2+ ion (Kd about 0.1 mM). Replacement of Mg2+ with Mn2+ caused a dramatic broadening of the NMR signal, indicating that the metal ion binds in proximity to the protein-bound F- (less than 1 nm). 31P NMR of GDP-G alpha showed peaks at -2 and -8.6 ppm, corresponding to the beta- and alpha-phosphoryl groups of GDP, respectively. Binding of Al3+, Mg2+, and F- caused an upfield shift of 6 ppm for the beta-phosphoryl signal with no change in the alpha-phosphoryl signal. These observations indicate that Mg2+.GDP.AlF3-5 mimics Mg2+.GTP in its capacity to activate G protein alpha subunits.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3396-401
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
19F and 31P NMR spectroscopy of G protein alpha subunits. Mechanism of activation by Al3+ and F-.
pubmed:affiliation
Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't