A strain C4 with ability of bioconversion from steroid RSA to hydrocortisone was selected fron the soil sample. It was identifide as Cuvularia Iunata according its morphological characters of clump and individuals. The optimum culture medium was established by orthogonal experiments :glucose 10g ,soybean powder 10g,water 1000mL, pH6.5. Determined by silica gel chromatography and high-performance liquid chromatography, the bioconversion ratio of hydrocortisone was 34%. At the same tine, the percentage change of RSA,hydrocortisone and other byproducts were measured during the course of bioconversion.

To improve 3-ketosteroid-△1-dehydrogenase (KSDH) activity and the transformation level for androst-4-ene-3,17-dione,3-ketosteroid-△1 -dehydrogenase gene (ksdD) from Arthrobacter simplex was cloned into plasmid pWB980 and expressed in B. subtilis WB600 under the control of promoter P43. The molecular weight of expressed enzyme was about 55kDa by SDS-PAGE analysis. The activitities assayed by spectrophotometrical method of intracellular and extracellular soluble enzyme were 110 ± 0.5mU and 15 ± 0.6mU per milligram of protein respectively. The transformation rate of androst-4-ene-3,17-dione by the B. subtilis recombinant cells was 45.3%. Compared with Arthrobacter simplex, the enzyme activity of KSDH expressed in B. subtilis was improved about 30 fold, and the transformation level of androst-4-ene-3,17-dione by the B.subtilis recombinant cells was improved about 10 fold. The recombinant B. subtilis cells used in biotransformation of steroids provided a new way for steroid medicines production.

A strain C4 with ability of bioconversion from steroid RSA to hydrocortisone was selected fron the soil sample. It was identifide as Cuvularia Iunata according its morphological characters of clump and individuals.The optimum culture medium was established by orthogonal experiments:glucose 10g,soybean powder 10g,water 1000mL, pH6.5.Determined by silica gel chromatography and high performance liquid chromatography, the bioconversion ratio of hydrocortisone was 34%.At the same tine, the percentage change of RSA,hydrocortisone and other byproducts were measured during the course of bioconversion.

Live Yeast Cell Derivative (LYCD) was based on a living cells response to a controlled injury, which stimulated it to produce protective substance to increase cellular respiration and wound healing The experiment suggested that LYCD had the ability to improve cellular respiration, and this ability became strongest after the cell was treated with H 2O 2 for 15min, while the quantity of reduced glutathione (GSH) in LYCD reached the highest at 30min By contrast, almost the same biological activity of LYCD was observed under different stress conditions

The epithelial growth factor receptor interference (EGFRi) was obtained by synthetic primers. Overlapping PCR was used to produce EGFRi-IL-24 fusion gene, which is linked by Gly4Ser3. After sequence analysis, EGFRi-IL-24 was cloned into expression vector pPIC9k; EGFRi-IL-24/pPIC9k was linearized with SacI,and then transformed to electroporated pastoris GS115. Subsequently, positive clone was selected by G418 and PCR, and its phenotype was determined by SDS-PAGE and MTT assay. The results demonstrated that EGFRi-IL-24 protein was expressed and shown to have the potential for use in researches of its biological function and in clinical application.
Antineoplastic Agents ; pharmacology ; Genetic Vectors ; genetics ; Humans ; Interleukins ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Receptor, Epidermal Growth Factor ; antagonists & inhibitors ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology