Linked Life Data

14593094

Source:http://linkedlifedata.com/resource/pubmed/id/14593094

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-1-19
pubmed:abstractText
Distinct spatial approximations between residues within the secretin pharmacophore and its receptor can provide important constraints for modeling this agonist-receptor complex. We previously used a series of probes incorporating photolabile residues into positions 6, 12, 13, 14, 18, 22, and 26 of the 27-residue peptide and demonstrated that each covalently labeled a site within the receptor amino terminus. Although supporting a critical role of this domain for ligand binding, it does not explain the molecular mechanism of receptor activation. Here, we developed probes having photolabile residues at the amino terminus of secretin to explore possible approximations with a different receptor domain. The first probe incorporated a photolabile p-benzoyl-l-phenylalanine into the position of His(1) of rat secretin ([Bpa(1),Tyr(10)]secretin-27). Because His(1) is critical for function, we also positioned a photolabile Bpa as an amino-terminal extension, in positions -1 (rat [Bpa(-1),Tyr(10)]secretin-27) and -2 (rat [Bpa(-2),Gly(-1),Tyr(10)]secretin-27). Each analog was shown to be a full agonist, stimulating cAMP accumulation in receptor-bearing Chinese hamster ovary-SecR cells in a concentration-dependent manner, with the position -2 probe being most potent. They bound specifically and saturably, although the position 1 analog had lowest affinity, and all were able to label the receptor efficiently. Sequential specific cleavage, purification, and sequencing demonstrated that the sites of covalent attachment for each probe were high within the sixth transmembrane segment. This suggests that secretin binding may exert tension between the receptor amino terminus and the transmembrane domain to elicit a conformational change effecting receptor activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2894-903
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Spatial approximation between the amino terminus of a peptide agonist and the top of the sixth transmembrane segment of the secretin receptor.
pubmed:affiliation
Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic Scottsdale, Scottsdale, Arizona 85259, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't