Abstract
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%.