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IGF-1 is a multifunctional cell proliferation regulatory factor, is composed of single-chain basic polypeptide consisting of 70 amino acids, MW 7.6KD, containing three disulfide bonds. Its biological function is to stimulate mitosis, induction and promotion of cell differentiation. LR ~ 3-IGF-1 is in the IGF-1 based on the N-terminal 13 amino acids is added, and IGF-1 in the third bit Glu (E) is replaced with Arg (R), and its activity than that of IGF-1 activity higher in biotech companies to achieve large-scale production in the laboratory on the basis of a small test. This paper is divided into three parts: the first part: First, high-density fermentation of recombinant engineered bacteria to produce IGF-1, 10L fermenter inoculum size, IPTG concentration, induction time, dissolved oxygen, pH optimized using lactose and IPTG phase combined manner the induction, after optimization, the amount of inoculation, the IPTG concentration of 0.8mmol / L induced 4H, dissolved oxygen controlled at 40% -60%, the amount of target protein is 25% wet bacterial weight of 22g / L. Part II: Fermentation obtained microbial cells subjected to ultrasonic treatment, to obtain the inclusion bodies, the inclusion body was washed three times, using 2mol / L urea was washed 2 times, and washed with PBS once a certain extent improve the purity of the inclusion bodies, so that the amount of the expression of the target protein in the inclusion bodies was 50%. Using denaturing solution (0.1mol / L Tris-HCl, 1mmol / L EDTA, 10 mmol / L, DTT, 8mol / L Urea, pH 8.0) enables the inclusion bodies completely dissolved, and is conducive to the subsequent folding. Considered in the process of refolding, the pH of the refolding of the protein concentration in the refolding redox ratio on the effect of refolding, the refolding method the experimental optimum refolding solution was 0.1 mol / L Tris-HCl, 1mmol / LEDTA, 3mmol/LGSSG, 1mmol / L GSH, 1% Gly pH8.0. After dilution of 4 ° C or stirred 12h. Using SephadexG-50 and SP.sepharose FF chromatography method of combining the purified, refolded IGF-1, and after purification of IGF-1, purity, molecular weight the full wavelength measured, the results with theoretical values match. Part III: on the basis of laboratory-based small test process under GMP conditions, successfully achieved enlarge LR3-IGF-1 protein production process, the establishment of a large-scale purification of LR3-IGF-Ⅰ purification route. Stable 150L fermentor fed-batch fermentation process, fermentation 12 hours after harvest the bacterial approximately 24g / L, through the combination of different chromatography and optimize the various parameters, to establish a stable, simple, easy to enlarge the pilot purification process. Renaturation after centrifugation and ion exchange chromatography and other means to remove part of the magazine ingredients during finished the rough on the basis of pure hydrophobic chromatography and gel filtration to minimize costly and time-consuming process of chromatography steps to simplify the entire processes. Compared with foreign processes, the process steps to shorten the purification cycle, and reduce the production cost,
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