Objective： To investigate the antibacterial mechanism of high-mobility group nucleosomal-binding domain 2 （HMGN2） on Escherichia coil K12, focusing on the antibacterial and antibiofilm formation effects. Its chemot...Objective： To investigate the antibacterial mechanism of high-mobility group nucleosomal-binding domain 2 （HMGN2） on Escherichia coil K12, focusing on the antibacterial and antibiofilm formation effects. Its chemotactic activity on human neutrophils was also investigated. Methods： Human tissue-derived HMGN2 （tHMGN2） was extracted from fresh uterus fiber cystadenoma and purified by HPl100 reversed-phase high-performance liquid chromatography （RP-HPLC）. Recombinant human HMGN2 （rHMGN2） was generated in E. coil DE3 carrying PET-32a- c（＋）-HMGN2. Antibacterial activity of HMGN2 was determined using an agarose diffusion assay and minimum inhibitory concentration （MIC） of HMGN2 was determined by the microdilution broth method. Bacterial membrane permeability assay and DNA binding assay were performed. The antibiofilm effect of HMGN2 was investigated using a crystal violet assay and electron microscopy scanning. The activating effect and chemotactic activity of HMGN2 on neutrophils were determined using a nitroblue tetrazolium （NBT） reduction assay and Transwell chamber cell migra- tion assay, respectively. Results： HMGN2 showed a relatively high potency against Gram-negative bacteria E. coli and the MIC of HMGN2 was 16.25 μg/ml. Elevated bacterial membrane permeability was observed in HMGN2-treated E. coil K12. HMGN2 could also bind the bacterial plasmid and genomic DNA in a dose-dependent manner. The antibiofilm effect of HMGN2 on E. coil K12 was confirmed by crystal violet staining and scanning electron microscopy. However, the activating effects and chemotactic effects of HMGN2 on human neutrophils were not observed. Con- clusions： As an antimicrobial peptide （AMP）, HMGN2 possessed a good capacity for antibacterial and antibiofilm activities on E. coil K12. This capacity might be associated with disruption of the bacterial membrane and combination of DNA, which might affect the growth and viability of E. coil.展开更多
基金supported by the National Natural Science Foundation of China(Nos.30470763,81470931,and 31401188)the China Medical Board of New York(No.98-861)the Youth Foundation of Sichuan University(No.2014SCU11042),China
文摘Objective： To investigate the antibacterial mechanism of high-mobility group nucleosomal-binding domain 2 （HMGN2） on Escherichia coil K12, focusing on the antibacterial and antibiofilm formation effects. Its chemotactic activity on human neutrophils was also investigated. Methods： Human tissue-derived HMGN2 （tHMGN2） was extracted from fresh uterus fiber cystadenoma and purified by HPl100 reversed-phase high-performance liquid chromatography （RP-HPLC）. Recombinant human HMGN2 （rHMGN2） was generated in E. coil DE3 carrying PET-32a- c（＋）-HMGN2. Antibacterial activity of HMGN2 was determined using an agarose diffusion assay and minimum inhibitory concentration （MIC） of HMGN2 was determined by the microdilution broth method. Bacterial membrane permeability assay and DNA binding assay were performed. The antibiofilm effect of HMGN2 was investigated using a crystal violet assay and electron microscopy scanning. The activating effect and chemotactic activity of HMGN2 on neutrophils were determined using a nitroblue tetrazolium （NBT） reduction assay and Transwell chamber cell migra- tion assay, respectively. Results： HMGN2 showed a relatively high potency against Gram-negative bacteria E. coli and the MIC of HMGN2 was 16.25 μg/ml. Elevated bacterial membrane permeability was observed in HMGN2-treated E. coil K12. HMGN2 could also bind the bacterial plasmid and genomic DNA in a dose-dependent manner. The antibiofilm effect of HMGN2 on E. coil K12 was confirmed by crystal violet staining and scanning electron microscopy. However, the activating effects and chemotactic effects of HMGN2 on human neutrophils were not observed. Con- clusions： As an antimicrobial peptide （AMP）, HMGN2 possessed a good capacity for antibacterial and antibiofilm activities on E. coil K12. This capacity might be associated with disruption of the bacterial membrane and combination of DNA, which might affect the growth and viability of E. coil.
