Limits...
iTRAQ-coupled 2-D LC-MS/MS analysis of membrane protein profile in Escherichia coli incubated with apidaecin IB.

Zhou Y, Chen WN - PLoS ONE (2011)

Bottom Line: Cell division protease ftsH, an essential regulator in maintenance of membrane lipid homeostasis, was found to be overproduced in cells incubated with apidaecin IB.Its over-expression intensified the degradation of cytoplasmic protein UDP-3-O-acyl-N- acetylglucosamine deacetylase, which catalyzes the first committed step in the biosynthesis of the lipid A moiety of LPS, and thus leaded to the further unbalanced biosynthesis of LPS and phospholipids.Our findings suggested a new antibacterial mechanism of apidaecins and perhaps, by extension, for other proline-rich antimicrobial peptides.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore.

ABSTRACT
Apidaecins are a series of proline-rich, 18- to 20-residue antimicrobial peptides produced by insects. They are predominantly active against the gram-negative bacteria. Previous studies mainly focused on the identification of their internal macromolecular targets, few addressed on the action of apidaecins on the molecules, especially proteins, of bacterial cell membrane. In this study, iTRAQ-coupled 2-D LC-MS/MS technique was utilized to identify altered membrane proteins of Escherichia coli cells incubated with one isoform of apidaecins--apidaecin IB. Cell division protease ftsH, an essential regulator in maintenance of membrane lipid homeostasis, was found to be overproduced in cells incubated with apidaecin IB. Its over-expression intensified the degradation of cytoplasmic protein UDP-3-O-acyl-N- acetylglucosamine deacetylase, which catalyzes the first committed step in the biosynthesis of the lipid A moiety of LPS, and thus leaded to the further unbalanced biosynthesis of LPS and phospholipids. Our findings suggested a new antibacterial mechanism of apidaecins and perhaps, by extension, for other proline-rich antimicrobial peptides.

Show MeSH

Related in: MedlinePlus

Growth kinetics of E. coli incubated with apidaecin IB.Each value represents the mean optical density (OD) readings from two cultures.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3105997&req=5

pone-0020442-g001: Growth kinetics of E. coli incubated with apidaecin IB.Each value represents the mean optical density (OD) readings from two cultures.

Mentions: The antibacterial activity of apidaecin IB towards E. coli cells was evaluated by the broth micro-dilution assay. The MIC of apidaecin IB was found to be as 16 µg/ml. The growth kinetics of cells was subsequently assayed in the presence of 1/10 MIC of apidaecin IB. Compared to no apidaecin IB control, apidaecin IB started to inhibit E. coli growth at 0.5 h after its incubation (Figure 1). Two time points (1 h and 2 h) were therefore chosen in this study.


iTRAQ-coupled 2-D LC-MS/MS analysis of membrane protein profile in Escherichia coli incubated with apidaecin IB.

Zhou Y, Chen WN - PLoS ONE (2011)

Growth kinetics of E. coli incubated with apidaecin IB.Each value represents the mean optical density (OD) readings from two cultures.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105997&req=5

pone-0020442-g001: Growth kinetics of E. coli incubated with apidaecin IB.Each value represents the mean optical density (OD) readings from two cultures.
Mentions: The antibacterial activity of apidaecin IB towards E. coli cells was evaluated by the broth micro-dilution assay. The MIC of apidaecin IB was found to be as 16 µg/ml. The growth kinetics of cells was subsequently assayed in the presence of 1/10 MIC of apidaecin IB. Compared to no apidaecin IB control, apidaecin IB started to inhibit E. coli growth at 0.5 h after its incubation (Figure 1). Two time points (1 h and 2 h) were therefore chosen in this study.

Bottom Line: Cell division protease ftsH, an essential regulator in maintenance of membrane lipid homeostasis, was found to be overproduced in cells incubated with apidaecin IB.Its over-expression intensified the degradation of cytoplasmic protein UDP-3-O-acyl-N- acetylglucosamine deacetylase, which catalyzes the first committed step in the biosynthesis of the lipid A moiety of LPS, and thus leaded to the further unbalanced biosynthesis of LPS and phospholipids.Our findings suggested a new antibacterial mechanism of apidaecins and perhaps, by extension, for other proline-rich antimicrobial peptides.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore.

ABSTRACT
Apidaecins are a series of proline-rich, 18- to 20-residue antimicrobial peptides produced by insects. They are predominantly active against the gram-negative bacteria. Previous studies mainly focused on the identification of their internal macromolecular targets, few addressed on the action of apidaecins on the molecules, especially proteins, of bacterial cell membrane. In this study, iTRAQ-coupled 2-D LC-MS/MS technique was utilized to identify altered membrane proteins of Escherichia coli cells incubated with one isoform of apidaecins--apidaecin IB. Cell division protease ftsH, an essential regulator in maintenance of membrane lipid homeostasis, was found to be overproduced in cells incubated with apidaecin IB. Its over-expression intensified the degradation of cytoplasmic protein UDP-3-O-acyl-N- acetylglucosamine deacetylase, which catalyzes the first committed step in the biosynthesis of the lipid A moiety of LPS, and thus leaded to the further unbalanced biosynthesis of LPS and phospholipids. Our findings suggested a new antibacterial mechanism of apidaecins and perhaps, by extension, for other proline-rich antimicrobial peptides.

Show MeSH
Related in: MedlinePlus