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Published on: February 24, 2026
Functional expression of mouse insulin-like growth factor-I with food-grade vector in Lactococcus lactis NZ9000
1The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China.
Aims:
To functionally express the recombinant mouse insulin-like growth factor-I (rtmIGF-I) in Lactococcus lactis NZ9000 with a food-grade vector.
Methods And 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) .
Significance And Impact Of The Study:
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.
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