title: Effects of N-acetyl-L-cysteine-capped CdTe quantum dots on bovine serum albumin and bovine hemoglobin: isothermal titration calorimetry and spectroscopic investigations.
abstract: The interactions of N-acetyl-L-cysteine-capped CdTe quantum dots (QDs) with bovine serum albumin (BSA) and bovine hemoglobin (BHb) were investigated by isothermal titration calorimetry (ITC), fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible absorption, and circular dichroism techniques. Fluorescence data of BSA-QDs and BHb-QDs revealed that the quenching was static in every system. While CdTe QDs changed the microenvironment of tryptophan in BHb, the microenvironment of BSA kept unchanged. Adding CdTe QDs affected the skeleton and secondary structure of the protein (BSA and BHb). The ITC results indicated that the interaction between the protein (BSA and BHb) and QDs-612 was spontaneous and the predominant force was hydrophobic interaction. In addition, the binding constants were determined to be 1.19 × 10(5) L mol(-1) (BSA-QDs) and 2.19 × 10(5) L mol(-1) (BHb-QDs) at 298 K. From these results, we conclude that CdTe QDs have a larger impact on the structure of BHb than BSA.
authors.affiliation: School of Environmental Science and Engineering, China -America CRC for Environment & Health, Shandong University, Jinan, 250100, People's Republic of China. rutaoliu@sdu.edu.cn.
authors.forename: Haoyu
authors.initials: H
authors.lastname: Sun
authors.forename: Erqian
authors.initials: E
authors.lastname: Cui
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Tan
authors.forename: Rutao
authors.initials: R
authors.lastname: Liu
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D000818:Animals; D002152:Calorimetry, Differential Scanning; D002417:Cattle; D006454:Hemoglobins / Q000737:chemistry*; D017433:Protein Structure, Secondary; D045663:Quantum Dots / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D006454:Hemoglobins; D012710:Serum Albumin, Bovine; D000111:Acetylcysteine
keywords: Bovine Hemoglobin; Bovine Serum Albumin; Isothermal Titration Calorimetry; QDs; Spectroscopic Studies