title: Functional expression of mouse insulin-like growth factor-I with food-grade vector in Lactococcus lactis NZ9000.
abstract: OBJECTIVE
  To functionally express the recombinant mouse insulin-like growth factor-I (rtmIGF-I) in Lactococcus lactis NZ9000 with a food-grade vector.
  
  
  RESULTS
  The rtmIGF-I encoding sequence was inserted into secreted food-grade vector pLEB688 and transformed into L. lactis NZ9000. The expression of the recombinant protein rtmIGF-I was confirmed by tricine-SDS-PAGE analysis and Western blot. The concentration of this recombinant protein was 3 mg l(-1) in the medium fraction. Further experiment demonstrated that the recombinant protein was biologically active and promoted NIH3T3 cell proliferation in a concentration-dependent manner.
  
  
  CONCLUSIONS
  The rtmIGF-I was expressed in L. lactis and located into the medium fraction. The optimal final concentration which could promote NIH3T3 cell proliferation after incubation was 100 ng ml(-1) .
  
  
  CONCLUSIONS
  The rtmIGF-I was functionally expressed in L. lactis NZ9000 with a food-grade vector. Thus, the recombinant L. lactis NZ9000 could act as a host for the production of rtmIGF-I for further study. The recombinant strain could serve as an IGF-I delivery system.
authors.affiliation: The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: G
authors.initials: G
authors.lastname: Gao
authors.forename: J-J
authors.initials: JJ
authors.lastname: Qiao
authors.forename: C-H
authors.initials: CH
authors.lastname: Yang
authors.forename: D-Z
authors.initials: DZ
authors.lastname: Jiang
authors.forename: R-Q
authors.initials: RQ
authors.lastname: Li
authors.forename: J-J
authors.initials: JJ
authors.lastname: Su
authors.forename: H-J
authors.initials: HJ
authors.lastname: Xu
authors.forename: X-M
authors.initials: XM
authors.lastname: Zhang
authors.forename: Y-L
authors.initials: YL
authors.lastname: Bai
authors.forename: M-Q
authors.initials: MQ
authors.lastname: Qiao
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D005822:Genetic Vectors; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D013294:Lactococcus lactis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013002:Somatomedins / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I