Acyl carrier protein is a bacterial cytoplasmic target of cationic antimicrobial peptide LL-37

2015 ◽  
Vol 470 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Myung-Chul Chung ◽  
Scott N. Dean ◽  
Monique L. van Hoek
Keyword(s):  
Antimicrobial Peptide ◽  
Acyl Carrier Protein ◽  
Acid Synthesis ◽  
Membrane Disruption ◽  
Carrier Protein ◽  
Cytoplasmic Protein ◽  
Bacterial Killing ◽  
Cationic Antimicrobial Peptide ◽  
Antibiotic Resistant ◽  
Future Drug

In addition to membrane disruption, the cathelicidin antimicrobial peptide LL-37 translocates through the bacterial inner membrane to target intracellular molecules. Our data suggest that the CAMP LL-37 is able can specifically bind to the cytoplasmic protein AcpP resulting in the inhibition of fatty acid synthesis and bacterial killing. Our studies introduce a novel mechanism for cationic antimicrobial peptides, which may be useful in future drug development for the treatment of antibiotic-resistant bacterial infection.

Spermicidal efficacy of VRP, a synthetic cationic antimicrobial peptide, inducing apoptosis and membrane disruption

2017 ◽  
Vol 233 (2) ◽  
pp. 1041-1050 ◽  
Author(s):  
Prasanta Ghosh ◽  
Arpita Bhoumik ◽  
Sudipta Saha ◽  
Sandipan Mukherjee ◽  
Sarfuddin Azmi ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Membrane Disruption ◽  
Cationic Antimicrobial Peptide

scholarly journals Structure of the mitochondrial β-ketoacyl-[acyl carrier protein] synthase fromArabidopsisand its role in fatty acid synthesis

FEBS Letters ◽  
2004 ◽  
Vol 577 (1-2) ◽  
pp. 170-174 ◽  
Author(s):  
Johan G. Olsen ◽  
Anne V. Rasmussen ◽  
Penny von Wettstein-Knowles ◽  
Anette Henriksen
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acyl Carrier Protein ◽  
Acid Synthesis ◽  
Carrier Protein

scholarly journals The 1.3-Angstrom-Resolution Crystal Structure of β-Ketoacyl-Acyl Carrier Protein Synthase II from Streptococcus pneumoniae

2003 ◽  
Vol 185 (14) ◽  
pp. 4136-4143 ◽  
Author(s):  
Allen C. Price ◽  
Charles O. Rock ◽  
Stephen W. White
Keyword(s):  
Crystal Structure ◽  
Streptococcus Pneumoniae ◽  
Active Site ◽  
Acyl Carrier Protein ◽  
Substrate Binding ◽  
Acid Synthesis ◽  
Imidazole Ring ◽  
Antibacterial Drug ◽  
Carrier Protein ◽  
Essential Components

ABSTRACT The β-ketoacyl-acyl carrier protein synthases are members of the thiolase superfamily and are key regulators of bacterial fatty acid synthesis. As essential components of the bacterial lipid metabolic pathway, they are an attractive target for antibacterial drug discovery. We have determined the 1.3 Å resolution crystal structure of the β-ketoacyl-acyl carrier protein synthase II (FabF) from the pathogenic organism Streptococcus pneumoniae. The protein adopts a duplicated βαβαβαββ fold, which is characteristic of the thiolase superfamily. The two-fold pseudosymmetry is broken by the presence of distinct insertions in the two halves of the protein. These insertions have evolved to bind the specific substrates of this particular member of the thiolase superfamily. Docking of the pantetheine moiety of the substrate identifies the loop regions involved in substrate binding and indicates roles for specific, conserved residues in the substrate binding tunnel. The active site triad of this superfamily is present in spFabF as His 303, His 337, and Cys 164. Near the active site is an ion pair, Glu 346 and Lys 332, that is conserved in the condensing enzymes but is unusual in our structure in being stabilized by an Mg2+ ion which interacts with Glu 346. The active site histidines interact asymmetrically with Lys 332, whose positive charge is closer to His 303, and we propose a specific role for the lysine in polarizing the imidazole ring of this histidine. This asymmetry suggests that the two histidines have unequal roles in catalysis and provides new insights into the catalytic mechanisms of these enzymes.

The Arabidopsis stearoyl-acyl carrier protein-desaturase family and the contribution of leaf isoforms to oleic acid synthesis

2006 ◽  
Vol 63 (2) ◽  
pp. 257-271 ◽  
Author(s):  
Aardra Kachroo ◽  
John Shanklin ◽  
Edward Whittle ◽  
Ludmila Lapchyk ◽  
David Hildebrand ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Acyl Carrier Protein ◽  
Acid Synthesis ◽  
Carrier Protein

scholarly journals Purification and Biochemical Characterization of theMycobacterium tuberculosisβ-Ketoacyl-acyl Carrier Protein Synthases KasA and KasB

2001 ◽  
Vol 276 (50) ◽  
pp. 47029-47037 ◽  
Author(s):  
Merrill L. Schaeffer ◽  
Gautam Agnihotri ◽  
Craig Volker ◽  
Howard Kallender ◽  
Patrick J. Brennan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Acyl Carrier Protein ◽  
Acid Synthesis ◽  
Mycolic Acid ◽  
Carrier Protein ◽  
Mycolic Acids ◽  
E Coli ◽  
Long Chain

Mycolic acids are vital components of theMycobacterium tuberculosiscell wall, and enzymes involved in their formation represent attractive targets for the discovery of novel anti-tuberculosis agents. Biosynthesis of the fatty acyl chains of mycolic acids involves two fatty acid synthetic systems, the multifunctional polypeptide fatty acid synthase I (FASI), which performsde novofatty acid synthesis, and the dissociated FASII system, which consists of monofunctional enzymes, and acyl carrier protein (ACP) and elongates FASI products to long chain mycolic acid precursors. In this study, we present the initial characterization of purified KasA and KasB, two β-ketoacyl-ACP synthase (KAS) enzymes of theM. tuberculosisFASII system. KasA and KasB were expressed inE. coliand purified by affinity chromatography. Both enzymes showed activity typical of bacterial KASs, condensing an acyl-ACP with malonyl-ACP. Consistent with the proposed role of FASII in mycolic acid synthesis, analysis of various acyl-ACP substrates indicated KasA and KasB had higher specificity for long chain acyl-ACPs containing at least 16 carbons. Activity of KasA and KasB increased with use ofM. tuberculosisAcpM, suggesting that structural differences between AcpM andE. coliACP may affect their recognition by the enzymes. Both enzymes were sensitive to KAS inhibitors cerulenin and thiolactomycin. These results represent important steps in characterizing KasA and KasB as targets for antimycobacterial drug discovery.

scholarly journals Phage-encoded cationic antimicrobial peptide used for outer membrane disruption in lysis

2019 ◽  
Author(s):  
Ashley Holt ◽  
Jesse Cahill ◽  
Jolene Ramsey ◽  
Chandler O’Leary ◽  
Russell Moreland ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Outer Membrane ◽  
Genetic Selection ◽  
Helical Structure ◽  
Bioinformatic Analysis ◽  
Membrane Disruption ◽  
Bacterial Cells ◽  
New Paradigm ◽  
Cationic Antimicrobial Peptide

AbstractSpanins are required for the last step in bacteriophage lysis: the disruption of the outer membrane. Bioinformatic analysis has shown that ~15% of phages lack a spanin gene, which suggests an alternate mechanism of outer membrane disruption. To address this, we selected virulent podophage ϕKT as a spaninless exemplar and tested ϕKT genes for outer membrane disruption during lysis. Hypothetical novel gene 28 causes outer membrane disruption when co-expressed with ϕKT lysis genes and complements the lysis defect of a λ spanin mutant. Gp28 is a 56 aa cationic peptide with predicted amphipathic helical structure and is associated with the particulate fraction after lysis. Urea and KCl washes did not release gp28 from the particulate, suggesting a strong hydrophobic interaction with the membrane. Super high-resolution microscopy supports a primarily outer membrane localization for the peptide. Additionally, holin function is not required for gp28-mediated lysis. Gp28 is similar in size, charge, predicted fold, and membrane association to the human cathelicidin antimicrobial peptide LL-37. In standard assays to measure bactericidal and inhibitory effects of antimicrobial peptides on bacterial cells, synthesized gp28 performed equivalently to LL-37. The studies presented here suggest that ϕKT Gp28 disrupts bacterial outer membranes during lysis in a manner akin to antimicrobial peptides.SignificanceHere we provide evidence that ϕKT produces an antimicrobial peptide for outer membrane disruption during lysis. The disruptin is a new paradigm for phage lysis, and has no similarities to other known lysis genes. Many mechanisms have been proposed for the function of antimicrobial peptides, however there is not a consensus on the molecular basis of membrane disruption. Additionally, there is no established genetic selection system to support such studies. Therefore, the ϕKT disruptin may represent the first genetically tractable antimicrobial peptide.

scholarly journals NovelXanthomonas campestrisLong-Chain-Specific 3-Oxoacyl-Acyl Carrier Protein Reductase Involved in Diffusible Signal Factor Synthesis

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Zhe Hu ◽  
Huijuan Dong ◽  
Jin-Cheng Ma ◽  
Yonghong Yu ◽  
Kai-Hui Li ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Xanthomonas Campestris ◽  
Octanoic Acid ◽  
Acyl Carrier Protein ◽  
Acid Synthesis ◽  
Carrier Protein ◽  
Content Type ◽  
Diffusible Signal Factor ◽  
Acyl Chains

ABSTRACTThe precursors of the diffusible signal factor (DSF) family signals ofXanthomonas campestrispv.campestrisare 3-hydroxyacyl-acyl carrier protein (3-hydroxyacyl-ACP) thioesters having acyl chains of 12 to 13 carbon atoms produced by the fatty acid biosynthetic pathway. We report a novel 3-oxoacyl-ACP reductase encoded by theX. campestrispv.campestrisXCC0416 gene (fabG2), which is unable to participate in the initial steps of fatty acyl synthesis. This was shown by the failure of FabG2 expression to allow growth at the nonpermissive temperature of anEscherichia colifabGtemperature-sensitive strain. However, when transformed into theE. colistrain together with a plasmid bearing theVibrio harveyiacyl-ACP synthetase gene (aasS), growth proceeded, but only when the medium contained octanoic acid.In vitroassays showed that FabG2 catalyzes the reduction of long-chain (≥C8) 3-oxoacyl-ACPs to 3-hydroxyacyl-ACPs but is only weakly active with shorter-chain (C4, C6) substrates. FabG1, the housekeeping 3-oxoacyl-ACP reductase encoded within the fatty acid synthesis gene cluster, could be deleted in a strain that overexpressedfabG2but only in octanoic acid-supplemented media. Growth of theX. campestrispv.campestrisΔfabG1strain overexpressingfabG2requiredfabHfor growth with octanoic acid, indicating that octanoyl coenzyme A is elongated byX. campestrispv.campestrisfabH. Deletion offabG2reduced DSF family signal production, whereas overproduction of either FabG1 or FabG2 in the ΔfabG2strain restored DSF family signal levels.IMPORTANCEQuorum sensing mediated by DSF signaling molecules regulates pathogenesis in several different phytopathogenic bacteria, includingXanthomonas campestrispv.campestris. DSF signaling also plays a key role in infection by the human pathogenBurkholderia cepacia. The acyl chains of the DSF molecules are diverted and remodeled from a key intermediate of the fatty acid synthesis pathway. We report aXanthomonas campestrispv.campestrisfatty acid synthesis enzyme, FabG2, of novel specificity that seems tailored to provide DSF signaling molecule precursors.

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