title: [Secretion expression of cholera toxin B subunit in food-grading Lactococcus lactis expression system].
abstract: 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.
authors.affiliation: 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.
authors.forename: Qiang-zheng
authors.initials: QZ
authors.lastname: Sun
authors.forename: Zhen-jun
authors.initials: ZJ
authors.lastname: Li
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Yi-ting
authors.initials: YT
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Jin
authors.forename: Xiao
authors.initials: X
authors.lastname: Zheng
authors.forename: Xiao-ai
authors.initials: XA
authors.lastname: Zhang
authors.forename: Yan-wen
authors.initials: YW
authors.lastname: Xiong
authors.forename: Chang-yun
authors.initials: CY
authors.lastname: Ye
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Xu
mesh_terms: D002772:Cholera Toxin / Q000096:biosynthesis* / Q000378:metabolism*; D005516:Food Microbiology; D015870:Gene Expression; D005822:Genetic Vectors; D013294:Lactococcus lactis / Q000378:metabolism*
chemical_list: D002772:Cholera Toxin