Study On The Interactions Of Small Molecule With Serum Albumin Or Peptide And The Application Of Nano-materials In These Interactions

The aim of this paper is to study and expound the interaction of common food and drug molecules as well as metal ions with protein or peptides, to explore the affect of these molecules to the conformation of protein or peptides, and to evaluate the safety of these molecules. The interaction of these substances:food dye sunset yellow and β-carotene, chiral pesticides metolachlor, and anti-tumor drug10-hydroxycamptothecin with bovine serum albumin (BSA) were investigated by a variety of spectroscopic approaches, atomic force microscope and chemometrics to obtained some qualitative and quantitative information. And sheded some light on the effect of Al3+to the conformation and aggregation of Aβ, and the possible linkage in the conformational aspects of AD. What’s more, some effort also has been devoted to study the applications of two kinds of nanomaterials in drug carrier and drug treatment. The paper is summarized as follows:1. Interaction of Sunset yellow (SY) and β-carotene (BC) with (BSA) was investigated by fluorescence, UV-vis, FT-IR and circular dichroism spectral approaches. The binding information and the change of protein secondary structure are provided to compare the nature of the binding of the two kinds of food dye molecules to BSA. The results show that the binding of SY to BSA induced conformational changes of BSA, and BC is a comparatively safe food dye.2. Enantioselective binding interaction of the pesticides, metolachlor (RACmt) and its S-enantiomer (Smt), with BSA was investigated by spectroscopic approaches and chemometrics. The experiments showed that the binding constant between Smt and BSA is higer than that of RACmt and BSA, and Smt bound to site I of BSA, while Rmt bound to site II. It is apparent that BSA displays a stereoselective preference for Smt and Smt had a higher affinity than RACmt.3. Investigation of interaction of10-hydroxycamptothecin (HCPT), graphene oxide (GO), and BSA in aqueous solution was carried out by employing spectroscopic approaches, atomic force microscope and chemometrics. It was demonstrated that HCPT was readily to load onto GO via the π-π stacking interaction, and the binding interaction between HCPT and BSA was facilitated by the presence of GO. And a sensitive and quite selective fluorescence biosensing platform was developed for fluorescence-enhanced detection of BSA based on GO.4. Aggregation of Aβ40induced by Al3+was investigated using spectroscopic approaches, Atomic force microscope technique, and chemometrics. The results show that Al3+is a inducer of the transformation from initial random coil structure to β-sheet structure in Aβ40peptides, thus facilitate the aggregation of Aβ40. And the binding constant was calculated by MCR-ALS method. The binding between PEGylated Fe3O4(PEG-Fe3O4) magnetic nanoparticles (MNPs) and Aβ40were studied, and PEG-Fe3O4MNPs were demonstrated to be promising potential treatment of AD pathology due to their affinity for capturing and eliminating this peptides.