Binding thermodynamics of synthetic dye Allura Red with bovine serum albumin.
The interaction between Allura Red and bovine serum albumin (BSA) was studied in vitro at pH 7.4. The fluorescence quenching was classified as static quenching due to the formation of AR-BSA complex, with binding constant (K) ranging from 3.26±0.09 to 8.08±0.0610(4)L.mol(-1), at the warfarin binding site of BSA. This complex formation was driven by increasing entropy. Isothermal titration calorimetric measurements also showed an enthalpic contribution. The Allura Red diffusion coefficient determined by the Taylor-Aris technique corroborated these results because it reduced with increasing BSA concentration. Interfacial tension measurements showed that the AR-BSA complex presented surface activity, since interfacial tension of the water-air interface decreased as the colorant concentration increased. This technique also provided a complexation stoichiometry similar to those obtained by fluorimetric experiments. This work contributes to the knowledge of interactions between BSA and azo colorants under physiological conditions.
Department of Food Technology, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Carini Aparecida
CA
Lelis
Department of Food Technology, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Eliara Acipreste
EA
Hudson
Department of Chemistry, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Guilherme Max Dias
GMD
Ferreira
Department of Chemistry, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Gabriel Max Dias
GMD
Ferreira
Department of Chemistry, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Luis Henrique Mendes
LHM
da Silva
Department of Chemistry, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil.
Maria do Carmo Hespanhol
MDCH
da Silva
Institute of Agrarian Sciences, Universidade Federal de Minas Gerais, Av. Universitária, 1000, Bairro Universitário, Montes Claros, MG 39404-547, Brazil.
Maximiliano Soares
MS
Pinto
Department of Food Technology, Universidade Federal de Viçosa, Av, PH Rolfs, s/n, Campus Universitário, Viçosa, MG 36570-000, Brazil. Electronic address: ana.pires@ufv.br.
Ana Clarissa Dos Santos
ACDS
Pires
D000818:Animals; D001391:Azo Compounds / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002151:Calorimetry; D002417:Cattle; D019277:Entropy; D005453:Fluorescence; D005505:Food Coloring Agents / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D001391:Azo Compounds; D005505:Food Coloring Agents; C005915:Allura Red AC Dye; D012710:Serum Albumin, Bovine
Diffusion coefficient; Enthalpy; Fluorescence; Interfacial tension; Synthetic food dye