LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides

Novel antibacterial drugs are in urgent need to overcome the continuous growth in the emergence of bacterial resistance to current antibiotics. Antibacterial peptides (ABPs), especially non-membrane-permeabilizing ABPs which kill bacteria by specific mechanisms other than direct membrane disruption,...

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Main Author: Zhou, Yusi
Other Authors: Chen Wei Ning, William
Format: Theses and Dissertations
Language:English
Published: 2012
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Online Access:https://hdl.handle.net/10356/50614
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-506142023-03-03T16:05:52Z LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides Zhou, Yusi Chen Wei Ning, William School of Chemical and Biomedical Engineering DRNTU::Engineering::Bioengineering Novel antibacterial drugs are in urgent need to overcome the continuous growth in the emergence of bacterial resistance to current antibiotics. Antibacterial peptides (ABPs), especially non-membrane-permeabilizing ABPs which kill bacteria by specific mechanisms other than direct membrane disruption, are excellent candidates for development as novel antibacterial drugs. Systematic and comprehensive understanding their mechanisms of action was thus urgently required. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique was utilized to analyze the protein profiles of Escherichia coli (E. coli) in response to the challenge of two representatives of non-membrane-permeabilizing ABPs, apidaecin IB and human neutrophil peptides 1 (HNP-1). A number of proteins which take essential roles in cellular protein quality control were found to be significantly changed. Levels of 60 kDa charperonin (GroEL) and 10 kDa charperonin (GroES), which together form the only essential chaperon system in E. coli cytoplasm under all growth conditions, were decreased; in contrast, levels of ATP-dependent protease ClpX and FtsH, which located in cytoplasm and inner membrane respectively, were increased. The increase in the proteases was probably involved in a compensatory response to the suppression effect. However, the overproduction of FtsH further intensified the degrading of UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC), an enzyme catalyzing the first committed step in the biosynthesis of the lipid A moiety of lipopolysaccharide (LPS). As the same reaction precursor (R-3-hydroxymyristoyl-ACP) is used by LpxC for the biosynthesis of the lipid A moiety of LPS and by (3R)-hydroxymyristoyl-[acyl-carrier-protein] dehydratase (FabZ) for the synthesis of fatty acid, the reduction in LpxC led to further unbalanced synthesis of LPS and phospholipids and the loss of membrane lipid homeostasis. However, in response to HNP-1 challenge, levels of a number of enzymes in glycolysis were decreased, including 6-phosphofructokinase isozyme 1, glyceraldehyde-3-phosphate dehydrogenase A, phosphoglycerate kinase, enolase, and pyruvate kinase; in contrast, levels of enzymes (dehydrogenase and aconitate hydratase 2) which regulate the conversion of pyruvate into isocitrate were increased. In concert with the decreasing in cellular ATP and the slowing down in the growth of E. coli culture, central metabolism was suggested to be involved in the E. coli response to HNP-1 challenge. DOCTOR OF PHILOSOPHY (SCBE) 2012-08-07T07:25:16Z 2012-08-07T07:25:16Z 2012 2012 Thesis Zhou, Y. (2012). LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/50614 10.32657/10356/50614 en 191 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Bioengineering
spellingShingle DRNTU::Engineering::Bioengineering
Zhou, Yusi
LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
description Novel antibacterial drugs are in urgent need to overcome the continuous growth in the emergence of bacterial resistance to current antibiotics. Antibacterial peptides (ABPs), especially non-membrane-permeabilizing ABPs which kill bacteria by specific mechanisms other than direct membrane disruption, are excellent candidates for development as novel antibacterial drugs. Systematic and comprehensive understanding their mechanisms of action was thus urgently required. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique was utilized to analyze the protein profiles of Escherichia coli (E. coli) in response to the challenge of two representatives of non-membrane-permeabilizing ABPs, apidaecin IB and human neutrophil peptides 1 (HNP-1). A number of proteins which take essential roles in cellular protein quality control were found to be significantly changed. Levels of 60 kDa charperonin (GroEL) and 10 kDa charperonin (GroES), which together form the only essential chaperon system in E. coli cytoplasm under all growth conditions, were decreased; in contrast, levels of ATP-dependent protease ClpX and FtsH, which located in cytoplasm and inner membrane respectively, were increased. The increase in the proteases was probably involved in a compensatory response to the suppression effect. However, the overproduction of FtsH further intensified the degrading of UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC), an enzyme catalyzing the first committed step in the biosynthesis of the lipid A moiety of lipopolysaccharide (LPS). As the same reaction precursor (R-3-hydroxymyristoyl-ACP) is used by LpxC for the biosynthesis of the lipid A moiety of LPS and by (3R)-hydroxymyristoyl-[acyl-carrier-protein] dehydratase (FabZ) for the synthesis of fatty acid, the reduction in LpxC led to further unbalanced synthesis of LPS and phospholipids and the loss of membrane lipid homeostasis. However, in response to HNP-1 challenge, levels of a number of enzymes in glycolysis were decreased, including 6-phosphofructokinase isozyme 1, glyceraldehyde-3-phosphate dehydrogenase A, phosphoglycerate kinase, enolase, and pyruvate kinase; in contrast, levels of enzymes (dehydrogenase and aconitate hydratase 2) which regulate the conversion of pyruvate into isocitrate were increased. In concert with the decreasing in cellular ATP and the slowing down in the growth of E. coli culture, central metabolism was suggested to be involved in the E. coli response to HNP-1 challenge.
author2 Chen Wei Ning, William
author_facet Chen Wei Ning, William
Zhou, Yusi
format Theses and Dissertations
author Zhou, Yusi
author_sort Zhou, Yusi
title LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
title_short LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
title_full LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
title_fullStr LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
title_full_unstemmed LC-MS/MS analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
title_sort lc-ms/ms analysis of the protein profiles of escherichia coli in response to the challenge of antibacterial peptides
publishDate 2012
url https://hdl.handle.net/10356/50614
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