Laura MacManus-Spencer - Development of a Fluorescence Model for the Binding of Medium- to Long-Chain Perfluoroalkyl Acids to Human Serum Albumin Through a Mechanistic Evaluation of Spectroscopic Evidence.

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      Publication Details (including relevant citation   information): Hebert, Paul C., MacManus-Spencer, Laura   A., Anal. Chem. (Washington, DC, U. S.),   2010, 82 (15), pp 6463-6471

      Abstract: A novel model for measuring the   strength of perfluoroalkyl acid (PFAA) binding to human serum   albumin (HSA) by use of the protein's native fluorescence is   described. The model is derived from published properties of HSA   and its interactions with other surfactants; it is consistent   with these properties and exptl. observations. The model's   validity has been tested with both medium- to long-chain PFAAs   (perfluoroheptanoate, perfluorooctanoate, perfluorononanoate,   perfluorodecanoate, perfluoroundecanoate,   perfluorohexanesulfonate, and perfluorooctanesulfonate) and   short-chain PFAAs (perfluorohexanoate and   perfluorobutanesulfonate). These expts. confirm the model as a   valid description for the binding of medium- to long-chain PFAAs   to HSA. Results indicate at least 2-3 PFAAs bind to each protein   with affinity on the order of 104 M-1. These binding strengths   exhibit a dependence on protein concn. Measured PFAA binding   consts. are approx. 10% of those values reported for fatty acids   of similar chain length; correcting for protein concn. suggests   the binding strengths may be as low as 2-3% of the corresponding   fatty acids' affinities. Like fatty acids, the carboxylate PFAAs   exhibit a trend of generally increasing binding strength with   increased chain length. The model does not appear valid for the   binding of short-chain PFAAs to HSA. Hill binding coeffs.,   fluorescence intensity measurements, and wavelengths of max.   emission suggest short-chain PFAAs assoc. with HSA differently   and fail to promote the same conformational changes in the   protein's tertiary structure as the medium- to long-chain PFAAs.   [on SciFinder(R)]

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