title: Purification and specificity of antibodies to adenosine.
abstract: Antibodies to adenosine were elicited in rabbits by immunization with bovine serum albumin-adenosine conjugate. The antibodies were purified and fractionated on two affinity columns (Sepharose-oligo(A) and Sepharose-AMP). Two families of antibodies have been obtained. The antibodies purified on the Sepharose-oligo(A) column react with poly(A) while those purified on the Sepharose-AMP column do not, as shown by gel diffusion. The association constants for the binding of Fab fragments or IgG purified on the Sepharose-oligo(A) column and several haptens were deduced from dialysis equilibrium, fluorescence quenching and displacement of AMP-fluorescein conjugate. The antibodies mainly recognize adenine, and the ribose or the phosphate group of (or AMP derivatives) do not play a critical role in the interaction. Thermodynamic parameters for adenosine-Fab fragments complexes have been determined deltaH degrees = 16 kcal/mole and deltaS degrees = - 15 cal. degree-1 mole-1. Circular dichroism studies indicate that about three nucleotide residues penetrate the binding site of Fab fragments.
mesh_terms: D000241:Adenosine / Q000276:immunology*; D000818:Animals; D000906:Antibodies / Q000302:isolation & purification; D000918:Antibody Specificity; D001666:Binding Sites, Antibody; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D003956:Dialysis; D006241:Haptens; D005779:Immunodiffusion; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D007700:Kinetics; D008433:Mathematics; D011233:Precipitin Tests; D011487:Protein Conformation; D011817:Rabbits / Q000276:immunology; D012710:Serum Albumin, Bovine; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000906:Antibodies; D006241:Haptens; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D012710:Serum Albumin, Bovine; D000241:Adenosine