中文摘要：

目的：研究重组人小分子抗体ScFv—Fc在毕赤酵母中分泌表达的最佳条件，以及ScFv—Fc的纯化方法。方法：分别从甲醇浓度、pH、诱导时间等方面对毕赤酵母重组菌株产生ScFv-Fc的发酵过程进行了优化；通过硫酸铵沉淀结合proteinA亲和层析柱，对ScFv—Fc的纯化方法进行了研究。结果：确定ScFv—Fc在毕赤酵母中分泌表达的最佳条件为：在pH5．2的条件下，以0．5％甲醇诱导72h。经过proteinA亲和层析柱纯化后，ScFv—Fc纯度可达94％以上。结论：确定了ScFv-Fe在毕赤酵母中分泌表达的最佳条件以及纯化方法，为重组抗体分子诊断、治疗试剂的开发以及抗体的人源化奠定了物质基础。

英文摘要：

Objective： To obtain an optimized fermentation and purification process for high-level production of a recombinant human antibody ScFv-Fc fragment expression secreted in Pichia pastoris. Methods： The growth conditions of the transformant strain were optimized in 50 ml conical tubes including pH, methanol concentration and inducing time. The ScFv-Fe was purified using a two-step scheme： ammonium aulfate fractionation, protein A Sepharose. Results： SeFv-Fc production was found to increase with 0.5% （v/v） methanol concentration after 72 b induction. Protein production was also greatly affected by pH, resulting in higher yields at 5.2 pH value. The ScFv-Fc was purified more than 94% purity by using protein A Sepharose. Conclusions： The results provided a best process for expression and purification of functional recombinant human monoclonal antibody ScFv-Fc. It suggests a potential use of this antibody generating method by Pichia pastoris and indicates the potential of scFv-Fc fusion proteins as therapeutic candidates.