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Published on: May 30, 2017
[Secretion expression of cholera toxin B subunit in food-grading Lactococcus lactis expression system]
Qiang-zheng Sun1, Zhen-jun Li, Juan Li
1State 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.
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.
Conclusion:
CTB was successfully secreted and expressed by food-grading L. lactis expression systems.
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