Interactions And Structure-activity Relationship Between Several Gold Nanoclusters And CtDNA/HSA

Gold nanoclusters(AuNCs)have broad application prospects in biosensing,biomarkers,bioimaging and diagnosis.At present,many genetic diseases,especially malignant tumors,are closely related to abnormal DNA activity.Serum albumin has the function of maintaining blood volume and plasma colloid osmotic pressure,transportation,detoxification and nutrition supply,both of which are the two most important biological macromolecules in human body.In addition,the development and research of related drugs are also very important,and the applications of nanomaterials in genetic materials has become a worldwide trend.However,there are few studies on the interaction between AuNCs and DNA(proteins).To better realize AuNCs applications in genetic and blood diseases,we need to understand the potential risks between AuNCs and DNA(proteins),whether and how it binds to DNA(proteins),and whether it affects the structure and function of DNA(proteins).Therefore,it is important to study the interactions between AuNCs and DNA(protein)in vitro.In order to further explore the structural-activity relationship of AuNCs interacting with DNA(protein)and guide the preparations and applications of AuNCs,the biological effects of AuNCs with different ligands on calf thymus DNA(ctDNA)and human serum albumin(HSA)were studied by using multiple spectral and non-spectral methods.The results provided theoretical basis for the preparations of AuNCs and the applications of metal nanoclusters at gene and protein levels.This paper was divided into five chapters as follows:Chapter 1: The synthesis,properties and applications of AuNCs and the interactions between AuNCs and DNA(HSA)were reviewed.Secondly,the concept of DNA(HSA)and the research methods of the interactions between AuNCs and these two biological macromolecules were introduced.Finally,the paper briefly introduced the topic selection and innovation points.Chapter 2: The interactions between DHLA-AuNCs(GSH-AuNCs)and ctDNA were studied in detail in this chapter.The results showed that there were slight differences in the mechanisms and binding forces between AuNCs and ctDNA.The quenching mechanism was completely different between both AuNCs and ctDNA-HO system.Binding constants indicated that the binding strength between DHLA-AuNCs and ctDNA was greater than that between GSH-AuNCs.The conformation studies showed that GSH-AuNCs had a greater influence on the conformation of ctDNA,and both AuNCs were more likely to interactwith the A-T base pairs of ctDNA.Chapter 3: The interactions between Cys-AuNCs(NAC-AuNCs)and ctDNA were studied in detail in this chapter.The results showed that there were slight differences in the interaction mechanisms and binding forces between these two kinds of AuNCs and ctDNA.The quenching mechanism was completely different between both AuNCs and ctDNA-HO system.The binding constants showed that the binding strength between NAC-AuNCs and ctDNA was greater than that of Cys-AuNCs.The conformation studies showed that the influence of NAC-AuNCs on the conformation of ctDNA was greater,and both AuNCs bound to the A and G base pairs of ctDNA by hydrogen bonds.Chapter 4: The interactions between Cys-AuNCs(NAC-AuNCs)and HSA were studied in detail in this chapter.The results showed that both AuNCs and HSA had the same interaction mechanisms,but the binding forces were slightly different.The quenching mechanism of HSA by both AuNCs was identical.The binding constants showed that the binding strength between NAC-AuNCs and HSA was greater than that of Cys-AuNCs.The conformation studies showed that both AuNCs had completely opposite effects on HSA amino acid microenvironment.In addition,Cys-AuNCs and NAC-AuNCs increased and decreased the ?-helix content of HSA,respectively,and both were more easily bound to lysine.Chapter 5: This chapter summarized the research contents and results,and prospected the future interactions between AuNCs and ctDNA(HSA).