LARGE-SCALE PRODUCTION & PURIFICATION OF COMPOUNDS WITH BIOLOGICAL ACTIVITY

生物技术股负责生物材料的生产和纯化。该股承担广泛的生物生产任务，如大规模生长原核生物和真核生物，以及生产和纯化生物化合物，特别是蛋白质。这些产品不能从商业来源获得，但需要用于临床和结构研究。生物技术股能够通过实施生理和技术方法来处理这些不同的生产任务。有效的工艺发展和生产是可能的，因为该股拥有两个综合要素：一个充分运作的多用途试验生产设施和进行研究和工艺发展的能力。去年，该单位进行了大约200种不同的大规模制备，包括：1)培养各种微生物，如重组大肠杆菌、重组酿酒酵母、重组毕赤酵母、白喉链杆菌突变株、几种沙门氏菌和志贺氏菌以及炭疽芽孢杆菌突变株；2)大量繁殖各种哺乳动物细胞，如HeLa、HEK 293、CHO；3)纯化制备结合疫苗所需的白喉毒素CRM （Cross reaction Material）和重组铜绿假单胞菌外毒素A的克量；4)利用填充床生物反应器从重组HEK 293细胞中产生人甲状旁腺Ca++受体的胞外结构域。在研究和开发领域，该部门继续开展以下主题的工作：1)开发更有效的大规模蛋白质回收方法，在这里我们进行了扩展床吸附技术的实验，用于捕获蛋白质洋葱交换剂，螯合和疏水树脂；2)利用核磁共振和质谱法研究不同重组大肠杆菌菌株的葡萄糖代谢，找出为什么某些菌株更适合生产外源蛋白；3)开发用于生产重组蛋白的果蝇细胞的发酵程序；4)改进毕赤酵母重组蛋白的生产工艺，特别是内皮抑素和血管抑素。此外，本单位还开展了两个课题的研究工作，一个是重组大肠杆菌的各种高密度生长策略对重组蛋白生产的影响，另一个是HeLa/牛痘系统重组蛋白的生产工艺。该股与非洲儿童疾病预防控制中心的LDMI合作，开展了研制伤寒沙门氏菌新疫苗的工作。该产品目前处于现场试验阶段。

The Biotechnology Unit is responsible for the production and purification of biological material. The Unit undertakes a wide array of biological production tasks such as large-scale growth of prokaryotes and eucaryotes, and production and purification of biological compounds especially proteins. These products, not available from commercial sources, are needed for clinical and structural studies. The Biotechnology Unit is capable of handling these various production tasks by implementing both physiological and technical approaches. Efficient process development and production is possible since the Unit possesses two integrated elements: a fully operational multi-purpose pilot production facility and the capability of conducting research and process development. During the last year the unit performed approximately 200 different, large scale preparations including: 1) growing various microorganisms such as recombinant Escherichia coli, recombinant Saccharomyces cerevisiae, recombinant Pichia pastoris, mutant strains of Corynebacteria diphtheria, several types of Salmonella and Shigella and mutant strain of Bacillus anthracis; 2) propagating large volumes of various mammalian cells such as HeLa, HEK 293 and CHO; 3) purifying gram quantities of diphtheria toxin CRM (Cross Reacting Material) and recombinant Pseudomonas aeruginosa exotoxin A needed for the preparation of conjugated vaccines; and 4) producing the extracellular domain of the human parathyroid Ca++ receptor from recombinant HEK 293 cells using a packed bed bioreactor. In the research and development arena, the unit continues its work in the following topics:1) development of more efficient methods for large scale protein recovery, here we performed experiments implementing expanded bed adsorption techniques for capturing proteins onion exchangers, chelating and hydrophobic resins; 2) conducting research aimed at understanding the glucose metabolism of various recombinant E. coli strains in an effort to find out why certain strains are more suitable for foreign protein production, using NMR and Mass Spectrophotometer methods; 3) developing fermentation procedures for growing Drosophila cells for the production of recombinant proteins; and 4) conducting experiments for improving the production protocol of recombinant proteins from Pichia pastoris, especially endostatin and angiostatin. In addition, the unit initiate research work in two topics, one is on the effect of various high density growth strategies of recombinant E. coli, on the production of recombinant proteins, and the other is on the production process of recombinant proteins from the HeLa/vaccinia system. In collaboration with LDMI, NICHD, the unit conducted work on the development of new vaccine against Salmonella typhi. The product is currently in field trial.