title: Human serum albumin-based design of a diflunisal prodrug.
abstract: The cyclooxygenase-2 inhibitor, diflunisal, is used in the clinic for its anti-inflammatory activity. About 99% of a dose of diflunisal is unavailable for reaction with the target enzyme, because diflunisal strongly binds to human serum albumin (HSA). To reduce the binding affinity of diflunisal to albumin, we designed and synthesized the prodrug acetyldiflunisal. The crystal structure of HSA complexed with fatty acid and acetyldiflunisal revealed that acetyldiflunisal binds to the IIA subdomain and that upon binding, it acetylates lysine 199. Mass spectrometry confirmed that acetyldiflunisal acetylates Lys199. The acetylated albumin had twofold weaker binding affinity for diflunisal as demonstrated by fluorescence quenching. Reduced binding affinity means that diflunisal is more easily released from acetylated albumin into the circulation. Therefore, lower doses of acetyldiflunisal compared to diflunisal will be required. Taken together, our results not only provide a template for design of HSA-based prodrugs, but also pave the way toward more effective use of diflunisal in the clinic.
authors: State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guangxi Normal University, Guilin, People's Republic of China.
authors: Feng
authors: F
authors: Yang
authors: Zhi Yuan
authors: ZY
authors: Ma
authors: Yao
authors: Y
authors: Zhang
authors: Guo Qing
authors: GQ
authors: Li
authors: Mei
authors: M
authors: Li
authors: Jiang Ke
authors: JK
authors: Qin
authors: Oksana
authors: O
authors: Lockridge
authors: Hong
authors: H
authors: Liang
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004061:Diflunisal / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000494:pharmacology; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D005227:Fatty Acids / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008239:Lysine / Q000737:chemistry; D011355:Prodrugs / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D012709:Serum Albumin; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D016861:Cyclooxygenase Inhibitors; D005227:Fatty Acids; D008024:Ligands; C585416:O-acetyldiflunisal; D011355:Prodrugs; D012709:Serum Albumin; D004061:Diflunisal; D008239:Lysine