Molecular probes for muscarinic receptors: derivatives of the M1-antagonist telenzepine

Karton, Yishai; Baumgold, Jesse; Handen, Jeffrey S.; Jacobson, Kenneth A.

doi:10.1021/bc00015a006

Cited by 14 publications

(23 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, a higher affinity was maintained in the telenzepine versus the pirenzepine derivatives, and the versatility of substitution at a terminal amino group enabled us to introduce chemically diverse reporter groups. Although the moderate selectivity for m1 receptors of 3 and 5 was diminished in most of the derivatives, modest m1 or m2 selectivity was restored in certain derivatives (9,10). Curiously, the selectivity could be modulated through distal structural changes.…”

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 95%

“…TAC was acylated with various reporter groups resulting in molecular probes of nanomolar affinity, and containing prosthetic groups for radioiodination, protein cross-linking, photoaffinity labeling, fluorescent labeling, and biotin for avidin complexation (10). Derivatives, in which TAC was conjugated to protein cross-linking reagents containing electrophilic groups designed for irreversible binding to the receptor, were prepared.…”

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 99%

“…Two such groups that proved to be effective for chemical affinity labeling of adenosine receptors, as well, were m-and p-phenylenediisothiocyanate (DITC). DITC-TAC isomers and other substituted aryl isothiocyanate derivatives were very effective irreversible inhibitors of muscarinic receptors (2,10,11). A p-aminophenylacetyl derivative of TAC designed for radioiodination and photoaffinity labeling of the receptor had a K i value of 0.29 nM at rat forebrain muscarinic receptors (16-fold higher affinity than telenzepine).…”

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 99%

“…The feasibility of using fluorescent techniques to measure ligand-receptor interactions has now been demonstrated with central benzodiazepine (13), A 2a -adenosine (5), muscarinic (10,25) and other receptors (16). Such fluorescent probes are potentially of use in histochemical studies and cell sorting, and complement existing radioreceptor assays.…”

Section: Fluorescent Tracers For Muscarinic Receptorsmentioning

confidence: 99%

See 3 more Smart Citations

Molecular probes for muscarinic receptors: Functionalized congeners of selective muscarinic antagonists

Fischer

Rhee

1995

Life Sciences

Self Cite

View full text Add to dashboard Cite

SummaryThe muscarinic agonist oxotremorine and the tricyclic muscarinic antagonists pirenzepine and telenzepine have been derivatized using a functionalized congener approach for the purpose of synthesizing high affinity ligand probes that are suitable for conjugation with prosthetic groups, for receptor cross-linking, fluorescent and radioactive detection, etc. A novel fluorescent conjugate of TAC (telenzepine amine congener), an n-decylamino derivative of the ml-selective antagonist, with the fluorescent trisulfonated pyrene dye Cascade Blue may be useful for assaying the receptor as an alternative to radiotracers. In a rat m3 receptor mutant containing a single amino acid substitution in the sixth transmembrane domain (Asn507 to Ala) the parent telenzepine lost 636-fold in affinity, while TAC lost only 27-fold. Thus, the decylamino group of TAC stabilizes the bound state and thus enhances potency by acting as a distal anchor in the receptor binding site. We have built a computer-assisted molecular model of the transmembrane regions of muscarinic receptors based on homology with the G-protein coupled receptor rhodopsin, for which a low resolution structure is known. We have coordinated the antagonist pharmacophore (tricyclic and piperazine moieties) with residues of the third and seventh helices of the rat m3 receptor. Although the decylamino chain of TAC is likely to be highly flexible and may adopt many conformations, we located one possible site for a salt bridge formation with the positively charged −NH 3 + group, i.e. Asp113 in helix II. Keywordstelenzepine; molecular modeling; fluorescence; G-protein coupled receptors An important strategy in our investigation of the structure and function of G-protein coupled receptors has been the synthesis of new ligands using a functionalized congener approach (1). By this approach, positions for attachment of chains on a pharmacophore are empirically probed, leading to knowledge of structure activity relationships at distal sites on a ligand. The site of attachment must correspond to a region of relaxed steric requirements for the ligand at or near the receptor binding site. This strategy has allowed us to target accessory sites of favorable interaction on the receptor, and actually enhance the affinity of the ligands (2). Potential applications include therapeutic agents (1) as well as ligand probes.By analogy, this design approach has been extensively explored by our laboratory at NIH for adenosine and ATP receptor ligands (1,(3)(4)(5) demonstrating that adenosine receptor subtypes are distinct molecular entities was accomplished using this methodology (6). Trifunctional affinity labels that direct a reporter group to the receptor binding site and then cause it to be covalently cross-linked to the protein have also been developed (3). It appears that the functionalized congener approach is a generally applicable approach, potentially useful with many receptors. Functionalized congener approach to muscarinic ligandsFunctionalized congeners related to the murcarinic...

show abstract

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 95%

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 99%

Section: Functionalized Congeners Related To Tricyclic Muscarinic Antmentioning

confidence: 99%

Section: Fluorescent Tracers For Muscarinic Receptorsmentioning

confidence: 99%

See 2 more Smart Citations

Molecular probes for muscarinic receptors: Functionalized congeners of selective muscarinic antagonists

Fischer

Rhee

1995

Life Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…14 Following purification by reverse-phase high-performance liquid chromatography (HPLC), purity was confirmed by mass spectrometry.…”

Section: Labeling Of M 1 Achr Nonpeptide Ligandsmentioning

confidence: 99%

Miniaturization of Fluorescence Polarization Receptor-Binding Assays Using CyDye-Labeled Ligands

Harris¹,

Cox²,

Burns³

et al. 2003

SLAS Discovery

View full text Add to dashboard Cite

Fluorescence polarization (FP) is an established technique for the study of biological interactions and is frequently used in the high-throughput screening (HTS) of potential new drug targets. This work describes the miniaturization of FP receptor assays to 1536-well formats for use in HTS. The FP assays were initially developed in 384-well microplates using CyDye-labeled nonpeptide and peptide ligands. Receptor expression levels varied from~1 to 10 pmols receptor per mg protein, and ligand concentrations were in the 0.5-to 1.0-nM range. The FP assays were successfully miniaturized to 1536-well formats using Cy3B-labeled ligands, significantly reducing reagent consumption, particularly the receptor source, without compromising assay reliability. Z′ factor values determined for the FP receptor assays in both 384-and 1536-well formats were found to be > 0.5, indicating the assays to be robust, reliable, and suitable for HTS purposes. (Journal of Biomolecular Screening 2003:410-420)

show abstract

Selective fluorescent ligands for pharmacological receptors

Baindur

Triggle

1994

Drug Development Research

View full text Add to dashboard Cite

Receptor-selective fluorescent ligands have come into increasing use as scientific tools for the study of receptor physiology and pathophysiology at the cellular and even the subcellular level. Furthermore, they are being increasingly investigated as tools in drug discovery research. In both cases, techniques employing receptor-selective fluorescent ligands have proved to be complementary to, and in several cases even superior to, the traditional-radioligand based techniques. increasing costs and public concerns associated with radioactive isotope use and dispersal are also making the use of fluoresecent ligands more attractive in research and diagnostic use. With the increasing rate of discovery of new receptors and receptor subtypes and newer more potent and/or selective receptor ligands and drugs, there will be an accompanying need for the design and development of new highly potent and selective fluorescent ligands to aid in the investigation of the physiological and pathophysiological functions of these new receptors and also in the development of drugs acting specifically at these receptors. This review presents a background of development of selected fluorescent ligands, primarily those for small molecule and small peptide based ligands. o 1994 \ViIey-Li

show abstract

Molecular probes for muscarinic receptors: derivatives of the M1-antagonist telenzepine

Cited by 14 publications

References 25 publications

Molecular probes for muscarinic receptors: Functionalized congeners of selective muscarinic antagonists

Molecular probes for muscarinic receptors: Functionalized congeners of selective muscarinic antagonists

Miniaturization of Fluorescence Polarization Receptor-Binding Assays Using CyDye-Labeled Ligands

Selective fluorescent ligands for pharmacological receptors

Contact Info

Product

Resources

About