Determination of the binding properties of p -cresyl glucuronide to human serum albumin
Résumé
p-Cresyl glucuronide (p-CG) is a by-product of tyrosine metabolism that accumulates in patients with end-stage renal disease. p-CG binding to human serum albumin in physiological conditions (37 degrees C, pH 7.40) was studied by ultrafiltration (MWCO 10kDa) and data were analyzed assuming one binding site. The estimated value of the association constant was 2.77x10(3)M(-1) and a maximal stoichiometry of 3.80mol per mole. At a concentration relevant for end-stage renal patients, p-CG was 23% bound to albumin. Competition experiments, using fluorescent probes, demonstrated that p-CG did not bind to Sudlow's site I or site II. The p-CG did not interfere with the binding of p-cresyl-sulfate or indoxyl sulfate to serum albumin.