title: Binding of the highly toxic tetracycline derivative, anhydrotetracycline, to bovine serum albumin.
abstract: Tetracycline (TC) derivatives are extensively used as antibiotics in human and animal medicine and, very recently, they have been screened as anti-amyloidogenic drugs. Anhydrotetracycline (AHTC) is one of the major degradation products of TC that has been linked to several side effects of the drug. We evaluated the interaction of AHTC with bovine serum albumin (BSA), one of the main carriers of amphiphilic molecules in blood, using three complementary analytical methods: fluorescence spectroscopy, isothermal titration calorimetry and differential scanning calorimetry. AHTC bound to BSA with an association constant in the order of 10(5) M(-1). Drug binding was enthalpically and entropically driven and seemed to involve hydrophobic interactions. AHTC fluorescence enhancement and hypsochromic shifts observed upon binding suggested a low-polarity location excluded from water for the bound drug. Our data are useful for evaluating the biodisponibility of the pharmacophore and the dynamic distribution of the toxic derivative.
authors.affiliation: Departamento de Química Biológica-Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina. inesburgos@fcq.unc.edu.ar
authors.forename: Martha Ines
authors.initials: MI
authors.lastname: Burgos
authors.forename: Ricardo Ariel
authors.initials: RA
authors.lastname: Fernández
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Celej
authors.forename: Laura Isabel
authors.initials: LI
authors.lastname: Rossi
authors.forename: Gerardo Daniel
authors.initials: GD
authors.lastname: Fidelio
authors.forename: Sergio Alberto
authors.initials: SA
authors.lastname: Dassie
mesh_terms: D000818:Animals; D002151:Calorimetry; D002417:Cattle; D002942:Circular Dichroism; D057927:Hydrophobic and Hydrophilic Interactions; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013752:Tetracycline / Q000009:adverse effects / Q000378:metabolism*; D013754:Tetracyclines / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D013816:Thermodynamics
chemical_list: D013754:Tetracyclines; D012710:Serum Albumin, Bovine; C016229:4-epianhydrotetracycline; D013752:Tetracycline