title: Binding analysis for interaction of diacetylcurcumin with β-casein nanoparticles by using fluorescence spectroscopy and molecular docking calculations.
abstract: The interaction of diacetylcurcumin (DAC), as a novel synthetic derivative of curcumin, with bovine β-casein (an abundant milk protein that is highly amphiphilic and self assembles into stable micellar nanoparticles in aqueous solution) was investigated using fluorescence quenching experiments, Forster energy transfer measurements and molecular docking calculations. The fluorescence quenching measurements revealed the presence of a single binding site on β-casein for DAC with the binding constant value equals to (4.40±0.03)×10(4)M(-1). Forster energy transfer measurements suggested that the distance between bound DAC and Trp143 residue is higher than the respective critical distance, hence, the static quenching is more likely responsible for fluorescence quenching other than the mechanism of non-radiative energy transfer. Our results from molecular docking calculations indicated that binding of DAC to β-casein predominantly occurred through hydrophobic contacts in the hydrophobic core of protein. Additionally, in vitro investigation of the cytotoxicity of free DAC and DAC-β-casein complex in human breast cancer cell line MCF7 revealed the higher cytotoxic effect of DAC-β-casein complex.
authors.affiliation: Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Mehranfar
authors.forename: Abdol-Khalegh
authors.initials: AK
authors.lastname: Bordbar
authors.forename: Najme
authors.initials: N
authors.lastname: Fani
authors.forename: Mehrnaz
authors.initials: M
authors.lastname: Keyhanfar
mesh_terms: D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D003474:Curcumin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D008024:Ligands; D061986:MCF-7 Cells; D008823:Micelles; D062105:Molecular Docking Simulation; D053758:Nanoparticles / Q000737:chemistry*; D009391:Nephelometry and Turbidimetry; D011485:Protein Binding / Q000187:drug effects; D012996:Solutions; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002364:Caseins; D008024:Ligands; D008823:Micelles; D012996:Solutions; C493686:diacetylcurcumin; D003474:Curcumin
keywords: Cytotoxic effect; Diacethylcurcumin; Fluorescence quenching; Forster’s theory; β-casein