Reconstruction and expression of human cathelicidin LL-37 in procaryotic cell
- VernacularTitle:人源LL-37杀菌多肽的改建及原核细胞中表达
- Author:
Xiaodong GE
;
Yousheng LIU
;
Yanli YANG
;
Jia ZOU
- Publication Type:Journal Article
- Keywords:
human cathelicidin LL-37;
confluent expression of protein;
strong cation exchange chromatography
- From:Journal of Third Military Medical University
2003;0(07):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To reconstruct the proteinic sequence of human cathelicidin LL-37 to increase the bactericidal activity of LL-37 and to express the reconstructed LL-37 (rLL-37) in bacterium. Methods The two dimensional structure, three dimensional structure and chemical characteristic of LL-37 were analyzed by Soft Ware Anthepro 5.0 and SWISS-MODEL. Without the three dimensional changes of LL-37, some negative amino acids of human cathelicidin LL-37 were replaced by positive amino acids and the positive charge of LL-37 was increased. According to the proteinic sequence changes of rLL-37, the DNA sequence of rLL-37 was reconstructed by Touch-Down PCR and recombined with vector pET-28a (+), thus rLL-37 was expressed in E.coli. BL21 (DE3) by the induction of IPTG and was purified by chromatography. Results Glu~ 16 , Asp~ 26 , Glu~ 36 of LL-37 were replaced by Gln~ 16 , Asn~ 26 , Gln~ 36 and the static charge of LL-37 was increased from +5.8 to +9.0 at pH 7.4. The DNA sequence of rLL-37 was reconstructed and inserted into vector pET-28a (+), the rLL-37 was expressed in E.coli. BL21 (DE3) and purified by strong cation exchange supports Macro-Prep High S successfully. The rLL-37 was proved by the means of inhibitory zone to be able to kill Gram-negative bacteria and Gram-positive bacteria. Conclusion It is feasible to reconstruct human cathelicidin LL-37 and express the protein in bacteria by fusion, which make it possible to produce more rLL-37 and study its biological function deeply.
