Bias Expresion Of Human Epidermal Growth Factor And Its Biochemical Pharmacological Characteristics

Human epidermal growth factor (hEGF) is a very important polypeptide in human body. It intensively promotes the proliferation and growth at very low dosage in many types of cells especially in protecting and repairing the alimentary canal epithelium cells and wound healing. The people who lack hEGF are vulnerable to the ulcerations of mouth, esophagus, stomach and duodenum. Although the chemical drugs are effective in the therapy of ulcers, the ulcer cicatrization is not perfect in some cases so-called the "red scar". Some pertinacious ulcers cannot be healed even after 1 year of treatment. The perfect cure only can be effected when using in combination with the hEGF. The human EGF transgenic tomato tastes fragrant and sweet, and is easy to plant with high yields. The development and utilization of the transgenic tomato will have a very good foreground in the health care and curing of the ulcers. Furthermore, the human EGF can be also widely used in the cosmetic.The hEGF gene was chemically synthesized according to codons bias in tomato. It has been proven in our study that the hEGF can be well expressed in tomato as well as in E.coli with fair physiological activity. The main results of our research are as follows: 1 The hEGF gene has been designed and synthesized according to the codons bias in tomato.2 Expression vectors p2300-35S-hEGF and p2300-2AU-hEGF suitable for expression in the cherry tomato has been constructed.3 The inheritance transformation system of the cherry tomato cg2001-14 has been set up.4 The hEGF gene has successful been inserted into the cherry tomato genome.5 The hEGF gene has been well expressed in the cherry tomato fruits.6 The transgenic cherry tomatos have shown obvious protective and therapeutic effects on acute peptic ulcers caused by ethanol in mice.7 An alternative effcient expression vector pGEX-4T-l-hEGF is constructed. The expression product GST-hEGF fusion protein is purified by Glutathione Sepharose 4B chromatography and shows complete biological function.8 A third vector pPTD-hEGF efficiently expressed in E.coli is also constructed. The PTD-hEGF fusion protein containing the protein transfer domain (PTD) is purified by Ni+2-NAT. The purified hEGF can penetrate the cell membranes and promote the proliferation of the cells.