Linked Life Data

17942747

Source:http://linkedlifedata.com/resource/pubmed/id/17942747

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-12-20
pubmed:abstractText
Delineation of peptide ligand binding sites is of fundamental importance in rational drug design and in understanding ligand-induced receptor activation. Molecular modeling and ligand docking to previously experimentally identified binding sites revealed a putative novel interaction between the C terminus of gonadotropin-releasing hormone (GnRH) and Arg(38(1.35)), located at the extracellular end of transmembrane domain 1 of the human GnRH receptor. Mutation of Arg(38(1.35)) to alanine resulted in 989- and 1268-fold reduction in affinity for GnRH I and GnRH II, respectively, the two endogenous ligands. Conservative mutation of Arg(38(1.35)) to lysine had less effect, giving reduced affinities of GnRH I and GnRH II by 24- and 54-fold, respectively. To test whether Arg(38(1.35)) interacts with the C-terminal Gly(10)-NH(2) of GnRH, binding of GnRH analogs with substitution of the C-terminal glycinamide with ethylamide ([Pro(9)-NHEt]GnRH) was studied with wild-type and Arg(38(1.35)) mutant receptors. Mutation of Arg(38(1.35)) to lysine or alanine had much smaller effect on receptor affinity for [Pro(9)-NHEt]GnRH analogs and no effect on binding affinity of peptide antagonist cetrorelix. In parallel with the decreased affinity, the mutants also gave a decreased potency to GnRH-elicited inositol phosphate (IP) responses. The mutant receptors had effects on [Pro(9)-NHEt]GnRH-elicited IP responses similar to that of the parent GnRHs. These findings indicate that Arg(38(1.35)) of the GnRH receptor is essential for high-affinity binding of GnRH agonists and stabilizing the receptor active conformation. The mutagenesis results support the prediction of molecular modeling that Arg(38(1.35)) interacts with the C-terminal glycinamide and probably forms hydrogen bonds with the backbone carbonyl of Pro(9) and Gly(10)-NH(2).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1521-0111
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
75-81
pubmed:dateRevised
2008-9-25
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Identification of a novel ligand binding residue Arg38(1.35) in the human gonadotropin-releasing hormone receptor.
pubmed:affiliation
MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't