1. Expression of bioactive recombinant GSLL-39, a variant of human antimicrobial peptide LL-37, in Escherichia coli
- Author
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Yang, Ying-Hua, Zheng, Guo-Guang, Li, Ge, Zhang, Xiu-Jun, Cao, Zhen-Yu, Rao, Qing, and Wu, Ke-Fu
- Subjects
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GENE expression , *ANTIMICROBIAL peptides , *ESCHERICHIA coli , *RECOMBINANT proteins - Abstract
The human cationic antimicrobial peptide hCAP-18/LL-37 is the unique cathelicidin identified in human to date. It has broad spectrum of antimicrobial activities and LPS-neutralizing activity and is involved in angiogenesis. Both purified and synthetic LL-37 or its derivatives were used in the study on LL-37. However, production of LL-37 in Escherichia coli has not been established. In this study, its precursor instead of the mature peptide was adopted for expression to avoid the lethal effect of recombinant LL-37 on host cells. A thrombin recognition site was introduced between the cathelin-like domain and LL-37 domain by overlap PCR to construct fragment encoding modified precursor (mhCAP-18) to facilitate the final release of the recombinant peptide. Then mhCAP-18 was fused in-frame to thioredoxin gene under the control of inducible T7 promoter to construct expression vector pET-mhCAP-18. The soluble form fusion protein was expressed in E. coli and purified by Chelating Sepharose column chromatography. Thrombin digestion of the fusion protein yielded recombinant GSLL-39, which was then purified by cation-exchange chromatography. Recombinant GSLL-39, which has two extra residues on its N-terminus when compared with its native counterpart, showed similar antimicrobial activities against both Gram-negative and Gram-positive bacteria. [Copyright &y& Elsevier]
- Published
- 2004
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