pH-dependency of basic ligand binding to α1-acid glycoprotein (orosomucoid)
- Urien, S Laboratoire de Pharmacologie, Faculté de Médecine, Université Paris XII, 8 Rue du Général Sarrail, F-94010 Créteil, France
- Brée, F Laboratoire de Pharmacologie, Faculté de Médecine, Université Paris XII, 8 Rue du Général Sarrail, F-94010 Créteil, France
- Testa, B Institut de Chimie Thérapeutique, École de Pharmacie, Université de Lausanne, CH-1015 Lausanne, Switzerland
- Tillement, J P Laboratoire de Pharmacologie, Faculté de Médecine, Université Paris XII, 8 Rue du Général Sarrail, F-94010 Créteil, France
Published in:
- Biochemical Journal. - Portland Press Ltd.. - 1991, vol. 280, no. 1, p. 277-280
English
The binding interactions of a series of basic ligands with alpha 1-acid glycoprotein (AAG) were examined as a function of pH. The binding to AAG increased with increasing pH, and the binding data were satisfactorily fitted to a model that incorporates the effect of pH and discriminates the association constants of neutral (non-protonated) and protonated forms of ligands. It was shown that ligands in the neutral form have a markedly higher affinity for AAG than the protonated forms, resulting in a concomitant decrease in the pKa of bound ligands. The u.v.-visible difference spectra generated upon binding of a representative ligand to AAG also showed that there was a contribution to the binding arising from the deprotonation of the ligand. It is suggested that all tested ligands bind similarly to AAG and that hydrophobic interactions dominate high-affinity binding to AAG.
- Language
-
- English
- Open access status
- green
- Identifiers
-
- DOI 10.1042/bj2800277
- ISSN 0264-6021
- Persistent URL
- https://sonar.ch/global/documents/85094
Statistics
Document views: 27
File downloads:
- Full-text: 0