Evaluation of a photolabile derivative of 1,25-dihydroxyvitamin D3 as a photoaffinity probe for 1,25-dihydroxyvitamin-D3 receptor in chick intestinal cytosol.
We evaluated the viability of 1 alpha, 25-dihydroxyvitamin D3-3 beta-[N-(4-azido-2-nitrophenyl)glycinate] (1,25-(OH)2-D3-ANG), an analog of 1 alpha, 25-dihydroxyvitamin D3 (1,25-(OH)2-D3) as a photoaffinity probe for 1,25-(OH)2-D3 receptor in chick intestinal cytosol. A competitive-binding assay revealed that chick intestinal cytosolic 1,25-(OH)2- D3 receptor bound to 1,25-(OH)2-D3-ANG approximately 20-times less effectively than it did to 1,25-(OH)2-D3. Irradiation of 1,25-(OH)2-D3- ANG in the presence of chick intestinal cytosolic preparation significantly diminished subsequent binding to 3H-1,25-(OH)2-D3, suggesting that the photoaffinity analog was covalently attached to the receptor. Therefore the nitroarylazide derivative of 1,25-(OH)2-D3 may be a valuable photoaffinity probe for the characterization of the 1,25-(OH)2-D3 receptor.
D000345:Affinity Labels / Q000378:metabolism*; D000818:Animals; D001386:Azides / Q000378:metabolism* / Q000528:radiation effects; D001667:Binding, Competitive; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000528:radiation effects; D002499:Centrifugation, Density Gradient; D002645:Chickens; D003600:Cytosol / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D010777:Photochemistry; D010782:Photolysis; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000378:metabolism*; D014466:Ultraviolet Rays
D000345:Affinity Labels; D001386:Azides; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; C047071:1,25-dihydroxyvitamin D3-3-(N-(4-azido-2-nitrophenyl)glycinate); D002117:Calcitriol