Studies On Proteins By Resonance Light Scattering Spectrometry

Protein is the most important life substance and plays an important role in animal life, such as poviding power, serving as the carrier of drug, microorganism and minerals. The amount of protein in human body is a reference for health. Therefore,to quantify protein in biochemistry is very important, which attracts the attentions of many scientists. The detection method of biomactomolecule has developed rapidly and become the important field of life science. The common analytical methods mainly include spectrophotometry and fluorimetry.Spectrophotometry suffers from low sensitivity. Fluorimetry is restricted by fluorimetric reagents. The scientists focus on finding a simple, quick and high sensitive method to determine the protein. Resonance light scattering spectrometry is a new technology which developed in 1990s for trace analysis. It was founded by pasternalk et al. in 1993. There have been more and more researches and applications of RLS recently. With high sensitivity, simplicity and rapidness, RLS has been applied widely in the fields of life sciences, environmental sciences and the investigation of nanometer materials. In this thesis, the assay for protein and the interaction between protein and probe were studied by resonance light scattering (RLS) technique. The surfactant always cooperates with RLS probe to enhance the RLS signal of system in the RLS technique for determination of proteins. In this thesis, the reduction agents (dithiothreitol andβ-mercaptoethanol) were introduced to the bovine serum albumin -sodium dodecylbenzene sulphonate system. Strong reduction agents can break down disulfide bond between cysteine amino acid residues and degrade protein. After the reduction agent was added into bovine serum albumin solution, the RLS intensity of bovine serum albumin -sodium dodecylbenzene sulphonate was enhanced. Based on the above results, a new assay for protein was established. The effects of some experimental conditions on the enhanced RLS intensity, such as concentrations of reduction agent and surfactant, pH values, coexistence ions and so on were investigated. Compared with the results obtained by Coomassie Brillant Blue(CBB) method, the experimental results obtained by the proposed method were satisfactory.Based on the phenomenon that (NH4)2SO4 can form large particles with protein by electrostatic forces to enhance the intensity of resonance light scattering (RLS), (NH4)2SO4 was used as a RLS probe to determine bovine serum alumin (BSA), human serum alumin (HSA) and ovum albumin (OVA). The experimental conditions were investigated, including the acidity and saturation of (NH4)2SO4. The effect of foreign substances was also examined. The real sample and synthetic samples were analyzed and the results were satisfactoriy.