(19)F NMR spectroscopic characterization of the interaction of niflumic acid with human serum albumin.

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Citation

Kitamura K, Omran AA, Takegami S, Tanaka R, Kitade T

(19)F NMR spectroscopic characterization of the interaction of niflumic acid with human serum albumin.

Anal Bioanal Chem. 2007 Apr;387(8):2843-8. doi: 10.1007/s00216-007-1162-x. Epub 2007 Feb 14.

PubMed ID
17377783 [ View in PubMed
]
Abstract

The interaction of a non-steroidal anti-inflammatory drug, niflumic acid (NFA), with human serum albumin (HSA) has been investigated by (19)F nuclear magnetic resonance (NMR) spectroscopy. A (19)F NMR spectrum of NFA in a buffered (pH 7.4) solution of NaCl (0.1 mol L(-1)) contained a single sharp signal of its CF(3) group 14.33 ppm from the internal reference 2,2,2-trifluoroethanol. Addition of 0.6 mmol L(-1) HSA to the NFA buffer solution caused splitting of the CF(3) signal into two broadened signals, shifted to the lower fields of 14.56 and 15.06 ppm, with an approximate intensity ratio of 1:3. Denaturation of HSA by addition of 3.0 mol L(-1) guanidine hydrochloride (GU) restored a single sharp signal of CF(3) at 14.38 ppm, indicating complete liberation of NFA from HSA as a result of its denaturation. These results suggest that the binding is reversible and occurs in at least two HSA regions. Competitive (19)F NMR experiments using warfarin, dansyl-L: -asparagine, and benzocaine (site I ligands), and L: -tryptophan and ibuprofen (site II ligands) revealed that NFA binds to site I at two different regions, Ia and Ib, in the ratio 1:3. By use of (19)F NMR with NFA as an (19)F NMR probe the nonfluorinated site I-binding drugs sulfobromophthalein and iophenoxic acid were also found to bind sites Ia and Ib, respectively. These results illustrate the usefulness and convenience of (19)F NMR for investigation of the HSA binding of both fluorinated and nonfluorinated drugs.

DrugBank Data that Cites this Article

Drugs
Drug Carriers
DrugCarrierKindOrganismPharmacological ActionActions
BenzocaineSerum albuminProteinHumans
Unknown
Binder
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