Effect Of CdSeS Nanoparticles On Glucagon Aggregation And The Toxicology Research Of Cells

The aggregation of protein is believed to be closely associated with many neurodegenerative disorders. The process of protein fibrillation is affected by several environmental factors such as temperature, pH value and ion strength. Now many studies have shown that abnormal accumulation and fibrillation of protein and polypeptide is closely related to the occurrence of nervous system diseases, such as alzheimer’s disease, Parkinson’s disease, diabetes, etc. The protein fibers have greatly toughness, so it has a broad application prospect in biological nanomaterials. Therefore, studying the fibrillation of the protein has become one of the most popular topic in physical, chemical, medicine and biology. With the rapid development of nanotechnology, nanoparticles materials have widely using in many fields, such as, cadmium selenide sulfide nanoparticles has been widely used in fluorescent probe and targeted delivering medicine. Glucagon plays an important physiological function, it is involved in regulating blood sugar levels and it is a kind of important hormone-like protein, it also has a strong tendency of fibrillation, so it is an ideal model molecules in studying of protein aggregation. Therefore, studying cadmium selenide sulfide nanoparticles on glucagon aggregation becomes more and more important. Copper ions can regulate the aggregation of peptides. The study also showed that in plasma and cerebrospinal fluid of Alzheimer’s patients,the content of copper was much higher than normal. There is also a lot of copper ions in the serum of diabetic patients. IAPP is an important pathogenic factors for non insulin-dependent diabetes. So we also studied the interaction between Cu2+ and IAPP. In this paper, we mainly do the following contents and achievements:(1) we have investigated the effect of Cadmium Selenide Sulfide nanoparticles(CdSeS NPs) on the fibrillation of glucagon peptides using AFM, FTIR and Fluorophotometer. We found that CdSeS NPs could inhibit glucagon peptide aggregation progress which was strongly dependent on the concentration of CdSeS NPs. In addition, the mechanism of interaction between glucagon and NPs was also discussed.(2) Atomic force microscopy was used to study the influence of different concentration of Cu2 + on the IAPP gathered, and we also used fluorescence photometer to detect the dynamic process of IAPP gathered. We found that with the increase of Cu2 + concentration, the fibrillation trend of IAPP gathered was more obvious. From the THT fluorescence data, we also could see that with the increase of Cu2 + concentration, the fluorescence intensity was more higher, the fluorescence intensity is proportional to the number of fiber gathered, so it proved that Cu2 + can promote the IAPP aggregation once again.(3) Fluorence microplate reader and MTT method were used to test the growth state of cells and how much reactive oxygen species(ROS) is produced.The experiment contained six groups. We found that as a result of the interaction between Cu2 + and IAPP, reactive oxygen species were produced and we used MTT colorimetry to detect the growth state of cells. In the last, we concluded that a small amount of active oxygen can also promote the growth of cells.