Linked Life Data

8568818

Source:http://linkedlifedata.com/resource/pubmed/id/8568818

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-3-1
pubmed:abstractText
Compute-aided conformational analysis was used to characterize the agonist pharmacophore for D1 dopamine receptor recognition and activation. Dihydrexidine (DHX), a high-affinity full agonist with limited conformational flexibility, served as a structural template that aided in determining a molecular geometry that would be common for other more flexible, biologically active agonists. The intrinsic activity of the drugs at D1 receptors was assessed by their ability to stimulate adenylate cyclase activity in rat striatal homogenates (the accepted measure of D1 receptor activation). In addition, affinity data on 12 agonists including six purported full agonists (dopamine, dihydrexidine, SKF89626, SKF82958, A70108, and A77636), as well as six less efficacious structural analogs, were obtained from D1 dopamine radioreceptor-binding assays. The active analog approach to pharmacophore building was applied as implemented in the SYBYL software package. Conformational analysis and molecular mechanics calculations were used to determine the lowest energy conformation of the active analogs (i.e., full agonists), as well as the conformations of each compound that displayed a common pharmacophoric geometry. It is hypothesized that DHX and other full agonists may share a D1 pharmacophore made up of two hydroxy groups, the nitrogen atom (ca. 7 A from the oxygen of m-hydroxyl) and the accessory ring system characterized by the angle between its plane and that of the catechol ring (except for dopamine and A77636). For all full agonists (DHX, SKF89626, SKF82958, A70108, A77636, and dopamine), the energy difference between the lowest energy conformer and those that displayed a common pharmacophore geometry was relatively small (< 5 kcal/mol). The pharmacophoric conformations of the full agonists were also used to infer the shape of the receptor binding site. Based on the union of the van der Waals density maps of the active analogs, the excluded receptor volume was calculated. Various inactive analogs (partial agonists with D1 K0.5 > 300 nM) subsequently were used to define the receptor essential volume (i.e., sterically intolerable receptor regions). These volumes, together with the pharmacophore results, were integrated into a three-dimensional model estimating the D1 receptor active site topography.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
285-96
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Conformational analysis of D1 dopamine receptor agonists: pharmacophore assessment and receptor mapping.
pubmed:affiliation
Brain and Development Research Center, School of Medicine, University of North Carolina, Chapel Hill, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't