[Secretion expression of cholera toxin B subunit in food-grading Lactococcus lactis expression system].
OBJECTIVE
To clone and secretion express cholera toxin B subunit (CTB) in food-grading Lactococcus lactis expression systems.


METHODS
ctB fragment that encoding CTB was amplified by polymerase chain reaction (PCR) using the genomic DNA of Vibrio cholera strain 569B as template and was inserted into two secretion expression vector pSQZ and pSQ to construct food-grading expression system L.lactis MBP71/pSQZ-ctB and L.lactis MBP71/pSQ-ctB. The expressed CTB was detected by Western-blot assay.


RESULTS
The ctB fragment was successfully amplified from Vibrio cholera strain 569B and inserted into two secretion expression vectors pSQZ and pSQ to construct food-grading expression system L. lactis MBP71/pSQZ-ctB and L. lactis MBP71/pSQ-ctB. Western-blot assay demonstrated that CTB was secretion and expressed from L.lactis MBP71 harboring vectors pSQZ-ctB and pSQ-ctB, and the quantity of CTB secreted by L. lactis MBP71/pSQ-ctB was about 2 microg/ml, higher than that of L. lactis MBP71/pSQZ-ctB.


CONCLUSIONS
CTB was successfully secreted and expressed by food-grading L. lactis expression systems.
Sun
Qiang-zheng
QZ
State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Li
Zhen-jun
ZJ
Li
Juan
J
Wang
Yi-ting
YT
Jin
Dong
D
Zheng
Xiao
X
Zhang
Xiao-ai
XA
Xiong
Yan-wen
YW
Ye
Chang-yun
CY
Xu
Jian-guo
JG
D002772:Cholera Toxin / Q000096:biosynthesis* / Q000378:metabolism*; D005516:Food Microbiology; D015870:Gene Expression; D005822:Genetic Vectors; D013294:Lactococcus lactis / Q000378:metabolism*
D002772:Cholera Toxin