Nucleic Acids Research, 1983, Vol. 11, No. 11 3581-3591
© 1983
MOLECULAR BIOLOGY |
Direct expression of hepatitis B surface antigen gene in E coli
Biotechnology Laboratories, Central Research Division, Takeda Chemical Industries Ltd. Osaka 532, Japan
Received March 21, 1983. Accepted May 6, 1983.
A 809 bp Sau 3A Hpa I fragment containing a complete HBsAg gene and fragments 744 bp Hinc II Hpa I and 712 bp Xba I Hpa I containing a truncated HBsAg gene lacking the sequence encoding the NH2terminal hydrophobic domain were prepared from a composite plasmid pHBV933 containing the 3.2 kb Eco RI DNA fragment of the entire HBV
adw genome and inserted into an expression vector pTRP801 to give plasmids pTRP SS-6, pTRP SS-39, and pTRP SS50, respectively. The growth of a recombinant having pTRP SS-6 was greatly inhibited and the transformant expressed a low level of HBsAg, which is reactive to human anti-HBsAg antibody. Interestingly, the growth of transformants harbouring pTRP SS-39 and pTRP SS50 was not inhibited and these transformants expressed a considerable level of the HBsAg. Minicells harbouring pTRP SS6, pTRP SS39, and pTRP SS50 formed specific polypeptides of about 24 K, 23 K, and 22 K daltons, respectively.