以E.coliDH5α基因组为模板PCR扩增得到无信号肽的碱性磷酸酶基因片段,与胞内融合表达型T载体连接得到重组质粒,转化表达宿主E.coliBL21(DE3)和E.coliorigami(DE3),经0.1 mM IPTG诱导表达,超声破碎细胞后,SDS-PAGE分析可溶性,融合蛋白在...以E.coliDH5α基因组为模板PCR扩增得到无信号肽的碱性磷酸酶基因片段,与胞内融合表达型T载体连接得到重组质粒,转化表达宿主E.coliBL21(DE3)和E.coliorigami(DE3),经0.1 mM IPTG诱导表达,超声破碎细胞后,SDS-PAGE分析可溶性,融合蛋白在E.coliorigami(DE3)中的可溶蛋白含量比E.coliBL21(DE3)中高.融合蛋白的可溶部分经Ni2+螯合亲和纯化,纯化后E.coliorigami(DE3)中蛋白活性比E.coliBL21(DE3)中明显提高,达到1 614.3U/mg蛋白.展开更多
The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and C...The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and CATH PR2, belong to the CATH family in the skin of P. robertingeri. CATH PR1 has a relatively high antimicrobial activity, especially for the drug-resistant strains found in clinical practice; however, no antimicrobial activity has been found in CATH PR2. The molecular weights of both CATH PR1 and CATH PR2 are relatively low （3195.88 and 2838.34 Da, respectively）. Thus, the genetic processes, as well as the expression and purification of these proteins, are difficult to perform. Therefore, in this study, CATH PR1 and CATH PR2 genes were tandem ligated and then connected to the plasmid pET-32a. This reconstructed plasmid was then transfected into the expression vector E. coli BL21 to construct the recombinant expression system. The fusion expression of peptide PR was stable in E. coli after induction with 1.0 mol/L isopropyl β-D-1-thiogalactopyranoside at 37℃ for 4 h. The antimicrobial activity assay using Staphylococcus aureus （Song） and Candida albicans 08030102 showed that the antimicrobial activity of PR was similar to the antimicrobial activity of CATH PR1. This study showed that artificial modification of the amino acid sequences of PR1 and PR2 could result in better protein expression in prokaryotes, and the fusion protein expressed had relatively high antimicrobial and other biological activities. In conclusion, the findings suggest future prospects of the commercialization of this method.展开更多
文摘以E.coliDH5α基因组为模板PCR扩增得到无信号肽的碱性磷酸酶基因片段,与胞内融合表达型T载体连接得到重组质粒,转化表达宿主E.coliBL21(DE3)和E.coliorigami(DE3),经0.1 mM IPTG诱导表达,超声破碎细胞后,SDS-PAGE分析可溶性,融合蛋白在E.coliorigami(DE3)中的可溶蛋白含量比E.coliBL21(DE3)中高.融合蛋白的可溶部分经Ni2+螯合亲和纯化,纯化后E.coliorigami(DE3)中蛋白活性比E.coliBL21(DE3)中明显提高,达到1 614.3U/mg蛋白.
基金supported by the Industry-University-Research Project of Application of the Active Substances from Amphibian Skin from the Education Ministry of Guizhou (Q. J. HE and K. Y. ZHI [2013]121)
文摘The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and CATH PR2, belong to the CATH family in the skin of P. robertingeri. CATH PR1 has a relatively high antimicrobial activity, especially for the drug-resistant strains found in clinical practice; however, no antimicrobial activity has been found in CATH PR2. The molecular weights of both CATH PR1 and CATH PR2 are relatively low （3195.88 and 2838.34 Da, respectively）. Thus, the genetic processes, as well as the expression and purification of these proteins, are difficult to perform. Therefore, in this study, CATH PR1 and CATH PR2 genes were tandem ligated and then connected to the plasmid pET-32a. This reconstructed plasmid was then transfected into the expression vector E. coli BL21 to construct the recombinant expression system. The fusion expression of peptide PR was stable in E. coli after induction with 1.0 mol/L isopropyl β-D-1-thiogalactopyranoside at 37℃ for 4 h. The antimicrobial activity assay using Staphylococcus aureus （Song） and Candida albicans 08030102 showed that the antimicrobial activity of PR was similar to the antimicrobial activity of CATH PR1. This study showed that artificial modification of the amino acid sequences of PR1 and PR2 could result in better protein expression in prokaryotes, and the fusion protein expressed had relatively high antimicrobial and other biological activities. In conclusion, the findings suggest future prospects of the commercialization of this method.
