Research On Cytochrome C Based New-type Self-assembled Systems

The catalytic performance and stability of small molecular protein with catalytic capabilities or cofactors can be greatly improved by modifications using physical, chemical and biological methods. Several self-assembled composite systems were constructed in this research using a small molecule protein cytochrome c(Cyt c) as a core component, combined with sodium decyl sulfate(SDeS) or deoxyribonucleic acid(DNA). The change of catalytic performance and conformation on the systems were then studied. This research may provide a sound theoretical basis for the studying the interactions between molecules of the body, researching or constructing new enzyme-mimic systems. In addition, a new method for detecting deoxyribonucleic acid bases was also introduced in this study, a new electrochemical biosensor was successfully acquired for detecting deoxyribonucleic acid bases using the piperazine modified reduced graphene oxide on a glassy carbon electrode.2, 2,-amino-bis(3-ethyl-benzothiazoline sulphonic acid-6 sulfonic acid)(ABTS) method was used for the assay. The results indicated that the catalytic performance of the assembled systems building with Cyt c and SDeS improved greatly respect to that of native Cyt c. The catalytic properties of composite systems can achieve 50.49% of the native horseradish peroxidase catalytic ability, The reasons causing this change may due to that the water environment around of Cyt c. where SDeS may be the main factor which cause the exposure of Cyt c active center, the results in this study are consistent with reported results.According to previous studies, new self-assembled systems was constructed using cyt c and a biological material, such as DNA. The systems was studies using the methods and technologies of biological properties molecular analysis, conformation analysis, bioinformatics analysis, and so, to offer new possibilities for exploring the interactions of biological molecules. In addition to the temperature, pH tolerance and other factors of the selected material, the research was set up in different conditions, including the setting of biological materials concentrations gradient for building self-assembled systems, the changing of different self-assembled conditions, and the comparing of self-assembled products performance under different conditions, etc. Eventually research built the Cyt c-DNA self-assembled systems under the condition of 65? water bath, constructed DNA-Cyt c composite systems having different DNA concentrations. Combining with ABTS method, research found the catalytic properties of Cyt c-DNA self-assembled systems change with the DNA concentrations. As the DNA concentrations increased, the catalytic properties increased gradually, and ultimately achieved stability, in this process, ultraviolet absorption capability of composite systems gradually receded, the maximum absorption peak occur certain redshift, in addition, the research analyzed by agarose gel electrophoresis, circular dichroism spectra and bioinformatics method, series of technologies show there are obvious interactions between DNA and Cyt c.Based on the studying of the spectroscopy about self-assembled systems building with Cyt c, the research built a new electrochemical biosensor for determining the deoxyribonucleic acid bases, it was built with piperazine modified reduced graphene oxide, and the electrochemical oxidation processes of bases were studied on the modified electrode by difference pulse voltammetry, the results showed it could be used for the separate or simultaneous detection of Adenine(A) and Guanine(G), and it showed lower detection limits and relatively wide detection range, A: 0.2 ?mol/L,0.2 ?mol/L- 125 ?mol/L; G: 0.1 ?mol/L, 0.2 ?mol/L-100 ?mol/L.