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Showing 1 to 20 of 50 for “"Lipid A"”.
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The role of lipid A in the virulence of ESKAPE pathogens
… septic shock.<br/><br/>Here we investigated the lipid A anchoring moiety of A. baumannii LOS which is the most pronounced pro-inflammatory molecule of A. baumannii. Several studies have elucidated A. baumannii lipid A modifications and their role in virulence. Therefore, we investigated the role …
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Periplasmic Modification of the 1-Phosphate Group of Lipid A in Gram-Negative Bacteria.
<p>Modification of the lipid A domain of lipopolysaccharide (LPS) is important for the pathogenesis and virulence of various Gram-negative bacteria. The major lipid A species of <em>Helicobacter pylori</em> is significantly different from that of <em>Escherichia coli</em>. <em>H. pylori</em> lipid …
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Structure-Guided Design of Novel Therapeutics Targeting Translesion DNA Synthesis and Lipid A Biosynthesis
<p>Cancer is one of the most devastating diseases in modern society, with over 1.6 million new cancer cases occurring in the US alone each year. DNA-damaging agents are often the first line of defense against rapidly dividing cancer cells. However, cancer cells can become resistant to chemotherapy …
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Mechanisms of Immuno-Modulation With The TLR4 Agonist Monophosphoryl Lipid A in the Treatment of Sepsis
Monophosphoryl lipid A (MPLA) is a Toll-like receptor 4 agonist that has been approved for use as a vaccine adjuvant in humans. In these studies, we evaluated the effect of MPLA treatment on the innate immune response to systemic infection in mice with emphasis on bacterial clearance, leukocyte …
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Structural Basis for Protein Recognition, Acyl-substrate Delivery, and Product Release by ACP in the Biosynthesis of Lipid A
… and dissociation. During biosynthesis of the lipid A component (endotoxin) of lipopolysaccharides, ACP shuttles acyl-intermediates thioester-linked to its 4'-phosphopantetheine arm among four acyltransferases: LpxA, LpxD, LpxL, and LpxM. LpxA and LpxD are essential cytoplasmic enzymes, which …
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Tandem mass spectrometry approaches to characterizing challenging biomolecules : stapled and cyclic peptides and variants of lipid A from gram-negative bacteria
… site on the peptidic backbone. Additionally, lipid A, the hydrophobic domain of lipopolysaccharide (LPS), consists of a diglucosamine backbone and is responsible for fastening LPS to a membrane surface. Lipid A becomes a biologically relevant molecule to study as its function within LPS is …
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Functional Studies of Acyl Carrier Protein and the Phosphopantetheinyl Transferase AcpT in Escherichia Coli K-12
… that has a temperature-sensitive phenotype and lipid A biosynthetic defect. I have mapped the mutation responsible for the lipid A biosynthetic defect and temperature-sensitive phenotype of this strain and have further characterized the suppression of the temperature-sensitive phenotype of …
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On the mechanisms of substrate translocation by the ABC transporter MsbA
… but also mediates the flopping of phospholipids and Lipid-A core across the plasma membrane. The MsbA protein has a similar fold as the mammalian multidrug resistance P-glycoproteins (P-gp, ABCB1) and might share functional features and substrate transport mechanisms with ABCB1. …
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LECTINS FROM THE HORSESHOE CRAB, LIMULUS POLYPHEMUS, REACTIVE WITH BACTERIAL LIPOPOLYSACCHARIDE
… also contains a lectin which interacts with the lipid A region of lipopolysaccharide; the proposed binding site in this region is the glucosamine backbone of the lipid A molecule.</p><p>A sialic acid-binding lectin from the serum of the horseshoe crab, Limulus polyphemus, was isolated by …
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LPS from subgingival plaque and the periodontal pathogen Porphyromonas gingivalis, its effect on M1 and M2 macrophage responses and potential as a biomarker
… (PG) is able to modify the bio-reactive lipid-A portion of LPS which in turn modifies immune response. The aims of this study were to characterise lipid-A profiles from subgingival plaque and PG LPS and determine their effects on MΦ biology. Lipid-A isolated from patient samples revealed …
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Investigations into the Lipid Transport Mechanisms and Energetics of Bacterial ATP-Binding Cassette (ABC) Transporters MsbA and LmrA
… been shown to mediate the transport of phospholipids, but the energetics of this process is unknown. To further examine the role of the sodium-motive force in the transport of a broader range of substrates, this PhD study investigated the transport of long-acyl-chain (2 x C18) headgroup …
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On the mechanisms of transport and energy coupling in ABC exporters
… using whole cells as well as artificial phospholipid membranes to study the energetics of transport, and the influence of membrane phospholipids on substrate transport by the homodimeric Escherichia coli lipid A/multidrug ABC exporter MsbA. Current alternating access models for ABC exporters …
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Structure-Based Drug Design in Medicinal Chemistry I. Development of Translesion Synthesis Inhibitors II. Synthesis and Biological Evaluation of Sulfonyl Piperazine Derivatives for LpxH Inhibition
… and biological evaluation of LpxH inhibitors. Lipid A has a critical role in host response to bacterial infection and thus is required for the growth and survival of most Gram-negative bacteria. An effective therapeutic targeting lipid A biosynthesis can cure Gram-negative bacterial infections …
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Activity of Epithelial Defensin HBD-3 Against a Periodontal Pathogen
… N-terminus of HBD-3 to the hydrophobic lipid A portion of LPS accounts for activity of HBD-3 against <em>A.a.</em></p> <p> Methods: Non-pathogenic <em>Escherichia coli</em> and pathogenic <em>A.a.</em> Y4 bacteria were incubated with recombinant HBD-3 or HNP-1 purified from human …
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Differential Interactions of Lipopolysaccharides with Lipid Bilayers: Applications for Pathogen Detection
… presentation of LPS by inserting the hydrophobic lipid A portion of the molecule into a lipid bilayer, leaving the O antigen exposed. This method is advantageous because it minimizes exposure of the highly conserved lipid A epitopes, and maximizes exposure of the serogroup specific O antigens. In …
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Differential Stimulation of Monocytes to Secrete Secretory Leukocyte Protease Inhibitor by Lipopolysaccharide of Periodontal Pathogens
… has three regions: oligosaccharide, core, and lipid A. Oligosaccharide is exposed on the cell surface, and lipid A anchors LPS in the outer membrane. Recent studies from our lab demonstrated that LPS of periodontal pathogens suppresses neutrophil's ability to secrete super oxide ions and also …
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IN VITRO SUSCEPTIBILITY OF CHLAMYDIA TRACHOMATIS TO LPS-BINDING POLYAMINES AND CELLULOSE ETHER POLYMERS: TOWARDS THE DEVELOPMENT OF A MICROBICIDE AGAINST CHLAMYDIA INFECTION
… polymyxin B (PMB) rationally designed to target lipid A portion of Gram-negative lipopolysaccharide (LPS). A wide range of anti chlamydial activity was observed among cellulose ether polymers, and 14 out of 18 PMB analogues exhibited greater than 60% inhibition of Chlamydia growth. Additionally, …
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