Computational studies of lipopolysaccharide interactions with membrane transporters

<p>Lipopolysaccharide (LPS) lipids compose the outer leaflet of the outer membrane in pathogenic Gram-negative bacteria and are chiefly responsible for host-immune responses. Therefore, the membrane proteins which interact with LPS as well as the transport system for LPS, the Lpt system, repre...

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Bibliografische gegevens
Hoofdauteur: Sauer, J
Andere auteurs: Stansfeld, P
Formaat: Thesis
Taal:English
Gepubliceerd in: 2022
Onderwerpen:
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author Sauer, J
author2 Stansfeld, P
author_facet Stansfeld, P
Sauer, J
author_sort Sauer, J
collection OXFORD
description <p>Lipopolysaccharide (LPS) lipids compose the outer leaflet of the outer membrane in pathogenic Gram-negative bacteria and are chiefly responsible for host-immune responses. Therefore, the membrane proteins which interact with LPS as well as the transport system for LPS, the Lpt system, represents a class of extremely important drug targets. The focus of this thesis is to employ molecular dynamics studies to examine the effects of LPS binding upon the Lpt complex at every stage of the transportation process, validating and conferring recent mass spectrometry and cryo-electron microscopy (Cryo-EM) studies.</p> <p>Molecular dynamics (MD) studies in this thesis reveal that LPS binds to other proteins found in the inner membrane in a similar manner to the transporter subcomplex LptB2FGC. Within the transporter itself, simulations of recently resolved Cryo-EM structure reveal that LPS shifts position to facilitate transportation across the periplasmic protein bridging complex. Binding energy calculations between the acyl chains of LPS and the bridging complex reveal a generally flat energetic landscape before reaching the terminal outer membrane subcomplex of the Lpt system, LptDE. Here, MD studies validate and explain hydrogen-deuterium exchange mass spectrometry results which capture the conformational changes required for LPS insertion into the outer membrane. With an increasing prevalence of antibiotic resistant pathogens, this thesis concerns characterising LPS interactions with its transport machinery suggesting means for developing antimicrobial therapeutics which target this essential system.</p>
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spelling oxford-uuid:06cf50d1-c83c-44da-97a6-844674f27a2e2023-03-09T10:31:59ZComputational studies of lipopolysaccharide interactions with membrane transportersThesishttp://purl.org/coar/resource_type/c_db06uuid:06cf50d1-c83c-44da-97a6-844674f27a2eStructural biologyNative mass spectrometryMolecular dynamicsHydrogen deuterium exchangeHDXEnglishHyrax Deposit2022Sauer, JStansfeld, PVivien Robinson, C<p>Lipopolysaccharide (LPS) lipids compose the outer leaflet of the outer membrane in pathogenic Gram-negative bacteria and are chiefly responsible for host-immune responses. Therefore, the membrane proteins which interact with LPS as well as the transport system for LPS, the Lpt system, represents a class of extremely important drug targets. The focus of this thesis is to employ molecular dynamics studies to examine the effects of LPS binding upon the Lpt complex at every stage of the transportation process, validating and conferring recent mass spectrometry and cryo-electron microscopy (Cryo-EM) studies.</p> <p>Molecular dynamics (MD) studies in this thesis reveal that LPS binds to other proteins found in the inner membrane in a similar manner to the transporter subcomplex LptB2FGC. Within the transporter itself, simulations of recently resolved Cryo-EM structure reveal that LPS shifts position to facilitate transportation across the periplasmic protein bridging complex. Binding energy calculations between the acyl chains of LPS and the bridging complex reveal a generally flat energetic landscape before reaching the terminal outer membrane subcomplex of the Lpt system, LptDE. Here, MD studies validate and explain hydrogen-deuterium exchange mass spectrometry results which capture the conformational changes required for LPS insertion into the outer membrane. With an increasing prevalence of antibiotic resistant pathogens, this thesis concerns characterising LPS interactions with its transport machinery suggesting means for developing antimicrobial therapeutics which target this essential system.</p>
spellingShingle Structural biology
Native mass spectrometry
Molecular dynamics
Hydrogen deuterium exchange
HDX
Sauer, J
Computational studies of lipopolysaccharide interactions with membrane transporters
title Computational studies of lipopolysaccharide interactions with membrane transporters
title_full Computational studies of lipopolysaccharide interactions with membrane transporters
title_fullStr Computational studies of lipopolysaccharide interactions with membrane transporters
title_full_unstemmed Computational studies of lipopolysaccharide interactions with membrane transporters
title_short Computational studies of lipopolysaccharide interactions with membrane transporters
title_sort computational studies of lipopolysaccharide interactions with membrane transporters
topic Structural biology
Native mass spectrometry
Molecular dynamics
Hydrogen deuterium exchange
HDX
work_keys_str_mv AT sauerj computationalstudiesoflipopolysaccharideinteractionswithmembranetransporters