New fluorescent adenosine A1-receptor agonists that allow quantification of ligand-receptor interactions in microdomains of single living cells.
Fluorescence spectroscopy is becoming a valuable addition to the array of techniques available for scrutinizing ligand-receptor interactions in biological systems. In particular, scanning confocal microscopy and fluorescence correlation spectroscopy (FCS) allow the noninvasive imaging and quantification of these interactions in single living cells. To address the emerging need for fluorescently labeled ligands to support these technologies, we have developed a series of red-emitting agonists for the human adenosine A1-receptor that, collectively, are N6-aminoalkyl derivatives of adenosine or adenosine 5'-N-ethyl carboxamide. The agonists, which incorporate the commercially available fluorophore BODIPY [630/650], retain potent and efficacious agonist activity, as demonstrated by their ability to inhibit cAMP accumulation in chinese hamster ovary cells expressing the human adenosine A1-receptor. Visualization and confirmation of ligand-receptor interactions at the cell membrane were accomplished using confocal microscopy, and their suitability for use in FCS was demonstrated by quantification of agonist binding in small areas of cell membrane.
Middleton
Richard J
RJ
School of Pharmacy, Centre for Biomolecular Sciences, and School of Chemistry, University of Nottingham, University Park, Nottingham, United Kingdom.
Briddon
Stephen J
SJ
Cordeaux
Yolande
Y
Yates
Andrew S
AS
Dale
Clare L
CL
George
Michael W
MW
Baker
Jillian G
JG
Hill
Stephen J
SJ
Kellam
Barrie
B
D000241:Adenosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D058907:Adenosine A1 Receptor Agonists; D000818:Animals; D001896:Boron Compounds / Q000737:chemistry*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000096:biosynthesis; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D021962:Membrane Microdomains / Q000378:metabolism*; D018613:Microscopy, Confocal; D011869:Radioligand Assay; D043682:Receptor, Adenosine A1 / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods; D013329:Structure-Activity Relationship
C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D058907:Adenosine A1 Receptor Agonists; D001896:Boron Compounds; D005456:Fluorescent Dyes; D008024:Ligands; D043682:Receptor, Adenosine A1; D000242:Cyclic AMP; D000241:Adenosine