title: [Affinity electrophoresis in polyacrylamide gel. Influence of the concentration in the gel on the apparent affinity of cholinesterase for an anionic ligand site].
abstract: Affinity electrophoresis of three purified molecular forms of human plasma cholinesterase (monomer C1, dimer C3, tetramer C4) was carried out in polyacrylamide gels at various total acrylamide concentrations ranging from 3.48 to 9% in a discontinuous buffer system. A water-soluble linear copolymer supporting procainamide, a ligand of the anionic site of cholinesterase, was physically entrapped at various concentrations within the gel network. The combined effects of gel concentration and ligand concentration on the affinity pattern of the three molecular forms were studied. It was found that gel concentration influences the apparent binding activity of their anionic site: The apparent strength of interaction varied with the gel concentration: the denser the gel was, the higher the apparent affinity. The ligand-induced isomerization process was also depending on the gel concentration: the ligand concentration from which each zone is splitting into two moving zones decreased as the total gel concentration increased. These results show that the electrophoretic matrix plays an important role in the affinity process in affinity electrophoresis presumably by controlling kinetic effects: kinetics of protein-ligand complex formation and dissociation reactions, and mass transfer kinetics.
mesh_terms: D002091:Butyrylcholinesterase / Q000097:blood; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002802:Cholinesterases / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D008024:Ligands; D011342:Procainamide
chemical_list: D008024:Ligands; D002091:Butyrylcholinesterase; D002802:Cholinesterases; D011342:Procainamide
vernacular_title: Electrophorèse d'affinité en gel de polyacrylamide. Influence de la concentration du gel sur l'affinité apparente de la cholinestérase pour un ligand de son site anionique.