H5亞型高病原性家禽流行性感冒病毒 (avian influenza virus, AIV)已對世界各地養禽產業與人類健康造成重大的威脅，血球凝集素 (hemagglutinin, HA)是流感病毒表面的膜蛋白之一，可以幫助病毒顆粒附著於細胞表面，促進病毒和細胞膜形成融合狀態，更是引發中和抗體的主要抗原，因此此蛋白質的純化和特性分析可以幫助加快疫苗的研發及檢測試劑的開發速度。由於桿狀病毒/昆蟲細胞表現系統已被廣泛應用於生產重組蛋白質，同時生產出的重組蛋白質和大腸桿菌及真菌表現系統相較之下，有較好的轉譯後修飾的能力，因此我們建構帶有HA基因的重組桿狀病毒，之後將放大後的病毒感染Sf-9，並在感染3天後將細胞離心下來。由影像分析系統可知，每公升的細胞培養液大約可以產生11.6毫克的HA。由於HA是一種膜蛋白，因此之後利用二階段萃取的方式打破細胞得到HA，再利用親和性管柱層析法 (lentil lectin)純化HA，純化的回收率約為38 %。

Highly pathogenic avian influenza virus (AIV) had threatened the poultry industry worldwide and human beings health. Hemagglutinin (HA), one of the influenza virus membrane proteins, plays a pivotal role in mediating the virus attachment and subsequent fusion and is the major antigen. Purification and characterization of HA thus becomes critical for the development of vaccines and diagnostic tools. Baculovirus/insect cell expression system has been widely used for recombinant protein production, thus we constructed a recombinant baculovirus, BacHA encoding the HA gene, for HA expression in insect cells (Sf-9). The infection resulted in successful expression and the yield amounted to 11.6 mg/l culture at 3 days post-infection as estimated by scanning densitometry. Since HA is a membrane glycoprotein, a two-staged scheme was adopted to extract HA. The extracted protein was subsequently purified by lentil lectin affinity chromatography and the recovery yield was estimated to be 38%.

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