title: Functional Analysis of Plantaricin E and Its Mutant by Heterologous Expression in Escherichia coli.
abstract: Plantaricins are a group of ribosomally synthesized antimicrobial peptides in Lactobacillus plantarum that exert antimicrobial activities against some foodborne pathogens. In this study, we observed that plantaricin E in L. plantarum 163 was missing 19 amino acids (plnE mutant amino acid sequence: FNRGGYNFGKSVRH, plnE amino acid sequence: FNRGGYNFGKSVRHVVDAIGSVAGIRGILKSIR). In order to study the effects of mutant plnE, plnE mutant genes with and without the signal peptide were cloned from the L. plantarum 163 genome, linked to the pET32a vector, and expressed via a fusion protein (thioredoxin) in Escherichia coli BL21 (DE3). All target proteins were purified using Ni-NTA, SP FF columns, and RP-HPLC. The purified proteins were stable in an acidic environment and at temperatures below 80 °C, but they were easily degraded under alkaline conditions and by protease treatment. They showed antimicrobial activity against gram-positive bacteria such as Micrococcus luteus, Staphylococcus epidermidis, Lactococcus lactis, Lactobacillus paracasei, and Listeria innocua. In addition, SP-plnE and PlnE exerted stronger activity than nisin. The signal peptide had a positive effect on the activities of PlnE and PlnEm. Thus, these purified proteins may have potential applications in the food industry to control foodborne pathogens.
authors.affiliation: College of Food Science and Technology, Nanjing Agriculture University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Fanqiang
authors.initials: F
authors.lastname: Meng
authors.affiliation: College of Food Science and Technology, Nanjing Agriculture University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Food Science and Technology, Nanjing Agriculture University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Lu
authors.affiliation: College of Food Science and Technology, Nanjing Agriculture University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Bie
authors.affiliation: College of Food Science and Technology, Nanjing Agriculture University, 1 Weigang, Nanjing, 210095, China. fmb@njau.edu.cn.
authors.forename: Zhaoxin
authors.initials: Z
authors.lastname: Lu
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D016680:Genome, Bacterial; D000069980:Lacticaseibacillus paracasei / Q000187:drug effects / Q000254:growth & development; D048191:Lactiplantibacillus plantarum / Q000235:genetics* / Q000378:metabolism; D013294:Lactococcus lactis / Q000187:drug effects / Q000254:growth & development; D008087:Listeria / Q000187:drug effects / Q000254:growth & development; D016982:Micrococcus luteus / Q000187:drug effects / Q000254:growth & development; D009154:Mutation; D021382:Protein Sorting Signals; D055550:Protein Stability; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D016415:Sequence Alignment; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000254:growth & development; D013329:Structure-Activity Relationship; D013879:Thioredoxins / Q000235:genetics* / Q000378:metabolism
chemical_list: D001430:Bacteriocins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D013879:Thioredoxins
keywords: Antimicrobial peptides; Mechanism model; Plantaricin; plnE mutant