title: Phenylbutazone and ketoprofen binding to serum albumin. Fluorescence study.
abstract: 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 KQ [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.
authors.affiliation: Medical University of Silesia, Department of Physical Pharmacy, Sosnowiec, Poland. Electronic address: mac.jurczyk@gmail.com.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Maciążek-Jurczyk
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism*; D001665:Binding Sites; D004347:Drug Interactions; D006801:Humans; D007660:Ketoprofen / Q000378:metabolism*; D010653:Phenylbutazone / Q000378:metabolism*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D012710:Serum Albumin, Bovine; D007660:Ketoprofen; D010653:Phenylbutazone
keywords: Competition; Serum albumin; Spectrofluorescence