Research Of The Interaction Mechanism Between Anthocyanin And Human Serum Albumin,Glycosylated Serum Protein

In this paper,the interaction mechanism between C3 G and HSA,gHSA,the quenching mechanism,the type of force,the number of binding sites,the binding capacity and the interaction sites were analyzed by fluorescencespectroscopy,FTIR,UV-vis,CD,molecular docking and so on.In addition,the effects of C3 G on the glycation of HSA,and the ability of anti-glycation of C3 G were further analyzed.Finally,the effects of C3 G,D3G and P3 G on the anti-glycation of HSA were compared and analyzed,and the anti-glycated ability of three kinds of anthocyanins was compared,moreover,the factors that might affect the ability of anti-glycation of the three kinds of anthocyanins were speculated.The paper provided some theoretical support for the prevention and control of diabetes.This paper was divided into the following sections:In the chapter one,the structure and physiological function of anthocyanins were classified.Morevoer,the basic structure of human serum albumin and the process of glycation were also introduced.The paper also studied the research progress on the effects of anthocyanins and serum proteins.Additionly,the application of related research techniques in the interaction between small molecules and proteins was reviewed.Finally,the paper described the purpose,significance and research aspects of this topic.In the chapter two,the interaction between C3 G and HSA,gHSA was studied by fluorescence,UV,FTIR,CD and molecular docking techniques.It was found that the binding mechanism between C3 G and HSA,gHSA were static quenching,and the main forces were hydrogen bond and van der waals force.Tryptophan and tyrosine residues in gHSA and HSA could be affected by C3 G,and the binding of C3 G to HSA,gHSA had little effect on the microenvironment of amino acid residues.In terms of the second structure,C3 G had a great influence on the secondary structure,and the glycated effect inhibitted the binding interaction.The pH dependence experiments showed that pH had a great effect on the binding of C3 G and protein.Moreover,when p H was 7.4,it had the strongest binding ability,and the protein structure had the N-B conversion.Molecular docking experiments also confirmed the above results to a certain extent.In the chapter three,the effect of C3 G on the glycation of HSA was studied through TEM,CD,FTIR,AFM and so on.It was found that the C3 G in buffer had the good stability during incubation period,and the surplus residue was enough to combine with HSA.In the incubation process,the particle size radius of HSA increased to a certain extent(about 10 nm),but there was no significant change in the secondary structure.Compared with glucose,C3 G had a greater influence on the structural stability of HSA,and there was a competitive relationship between them.In addition,it was found that C3 G could effectively inhibit the glycation of HSA by affecting the formation of AGEs.And through the comprehensive analysis of the related research on the experimental data,we speculated that the inhibitory effect of C3 G may be a major role in the formation of AGEs between second and third phase,it may affect the formation of AGEs through three different ways: inhibition of rearrangement of fructosamine,trapping of reactive carbonyl compounds and the inhibition of HSA intermolecular crosslinking.Furtherly,the effect of C3 G on the crosslinking of HSA was carried out.It was found that the effect of C3 G on the structure and surface roughness of HSA was probably the main reason for the inhibition of crosslinking.In the chapter four,the effects of C3 G,D3G and P3 G on the glycation of HSA were studied by UV-vis absorption spectra,fluorescence spectra,CD and AFM.The results showed that the three anthocyanins all could inhibit the production of HSA by affecting the formation of fructosamine and AGEs.Through the comparative analysis of three kinds of anthocyanins,it was found that three anthocyanins on the polarity of AGEs formation had varied degrees impacts(D3G,29 nm > C3 G,18 nm > P3 G,2 nm).Compared with C3 G,D3G and P3 G affected the absorbance of HSA sample(P3G > D3 G > C3G)more obvious at 280 nm.Anthocyanins could effectively prevent the fluorescence quenching of HSA samples induced by glucose,and the inhibition intensity was D3 G > P3 G > C3 G.The CD spectra showed that the influence of P3 G and D3 G on the HSA secondary structure were stronger than that of C3 G on HSA.Atomic force microscopy showed that D3 G,P3G did not play a protective role on the surface morphology of HSA,and the Rms roughness and average height of HSA samples were reduced to some extent.Based on the comprehensive analysis of the experimental data,we speculated that the difference of anthocyanin B ring was the main reason for the effect of anthocyanins on anti-glycated of HSA,which influenced the antioxidant and polarity of anthocyanins.