Phenylbutazone and ketoprofen binding to serum albumin. Fluorescence study

Background a combination of phenylbutazone (pbz) and ketoprofen (kp) is popular in therapy of rheumatoid arthritis (ra) but could be unsafe due to the uncontrolled growth of toxicity. methods quenching fluorescence of serum albumin in the presence of the both drugs has been characterized by dynamic k q [m-1],static v [m-1] quenching constants and also association constants ka [m-1]. results the quenching of tryptophanyl residues fluorescence by the kp and pbz indicates the capability of these drugs to accept the energy from trp-214 and trp-135. strong displacement of kp and pbz bound to albumin cause by the binding of the second drug to sa close to trp-214 (subdomain iia) has been obtained. the displacement was also confirmed on the basis of quenching and association constants. conclusions the conclusion,that both pbz and kp form a binding site in the same subdomains (iia or/and ib),points to the necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects. © 2014 institute of pharmacology,polish academy of sciences.