Human Interferon Beta In Pichia Pastoris Expression And Purification Of Activity Determination Of Human Apolipoprotein Proapoa-i Expression In E. Coli System,

The whole thesis consists of two parts:Part 1: Expression , purification and bioassay of rHuIFN- β in Pichia pastoris expression system. Part 2 : Expression of human pro Apo A-I in Escherichia coli expression system.Part 1:The interferons(IFNs) were first discovered in 1957 as biological agents interfering with virus replication. They are a unique class of cytokines capable of interfering with the viral infection of cells, as well as inhibiting the proliferation of normal and transformed cells, regulating cell differentiation, and modulating the immune system.Interferons are classified basically into three antigenically distinct groups, designated IFN-α , IFN-β and IFN- γ . They are also categorized by their sources as leukocyte, fibroblast, and immune IFNs.The native human IFN-β is a glycoprotein with an N-linked glycan at Asn80 site, which is secreted by fibroblasts in response to viral infection, or exposure to double-stranded RNA. After extensive basic research, IFN-β is now found to be of great therapeutical value in clinic for virus infection, autoimmune disease and malignant neoplasm. Interferons are widely studied in our country, but most domestic studies concentrated on IFN-α and IFN-γ. The studies on IFN-β are just at the beginning and few researches have been done yet.In this project, after analyzing the crystal structure, the nucleic acid sequence and the amino acid sequence of human IFN-β , we designed two site-directed mutageneses in human IFN- β nucleic acid sequence: one is 17 Cys TGT: :AGT Ser , the other is 165 Arg CGA: :AGA Arg. The mutagenesis 17 Cys TGT: :AGT Ser makes the protein more stable on structure level. And what' s more, the protein may be expressed at a high level 7mg/L in the...