Study on the interaction of a copper(II) complex containing the artificial sweetener aspartame with human serum albumin.
A copper(II) complex containing aspartame (APM) as ligand, Cu(APM)2Cl2·2H2O, was synthesized and characterized. In vitro binding interaction of this complex with human serum albumin (HSA) was studied at physiological pH. Binding studies of this complex with HSA are useful for understanding the Cu(APM)2Cl2·2H2O-HSA interaction mechanism and providing guidance for the application and design of new and more efficient artificial sweeteners drive. The interaction was investigated by spectrophotometric, spectrofluorometric, competition experiment and circular dichroism. Hyperchromicity observed in UV absorption band of Cu(APM)2Cl2·2H2O. A strong fluorescence quenching reaction of HSA to Cu(APM)2Cl2·2H2O was observed and the binding constant (Kf) and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy change (∆H) and entropy change (∆S) were calculated to be -458.67 kJ mol(-1) and -1,339 J mol(-1 )K(-1) respectively. According to the van't Hoff equation, the reaction is predominantly enthalpically driven. In conformity with experimental results, we suggest that Cu(APM)2Cl2·2H2O interacts with HSA. In comparison with previous study, it is found that the Cu(II) complex binds stronger than aspartame.
Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Islamic Republic of Iran, nahidshahabadi@yahoo.com.
Nahid
N
Shahabadi
Mohammad Mehdi
MM
Khodaei
Soheila
S
Kashanian
Fahimeh
F
Kheirdoosh
Soraya Moradi
SM
Filli
D001218:Aspartame / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D015394:Molecular Structure; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D013549:Sweetening Agents / Q000737:chemistry / Q000378:metabolism*; D013816:Thermodynamics
D012709:Serum Albumin; D013549:Sweetening Agents; D003300:Copper; D001218:Aspartame