177315-87-6Relevant articles and documents
Acyl-group specificity of AHL synthases involved in quorum-sensing in Roseobacter group bacteria
Ziesche, Lisa,Rinkel, Jan,Dickschat, Jeroen S.,Schulz, Stefan
, p. 1309 - 1316 (2018)
N-Acylhomoserine lactones (AHLs) are important bacterial messengers, mediating different bacterial traits by quorum sensing in a cell-density dependent manner. AHLs are also produced by many bacteria of the marine Roseobacter group, which constitutes a large group within the marine microbiome. Often, specific mixtures of AHLs differing in chain length and oxidation status are produced by bacteria, but how the biosynthetic enzymes, LuxI homologs, are selecting the correct acyl precursors is largely unknown. We have analyzed the AHL production in Dinoroseobacter shibae and three Phaeobacter inhibens strains, revealing strain-specific mixtures. Although large differences were present between the species, the fatty acid profiles, the pool for the acyl precursors for AHL biosynthesis, were very similar. To test the acyl-chain selectivity, the three enzymes LuxI1 and LuxI2 from D. shibae DFL-12 as well as PgaI2 from P. inhibens DSM 17395 were heterologously expressed in E. coli and the enzymes isolated for in vitro incubation experiments. The enzymes readily accepted shortened acyl coenzyme A analogs, N-pantothenoylcysteamine thioesters of fatty acids (PCEs). Fifteen PCEs were synthesized, varying in chain length from C4 to C20, the degree of unsaturation and also including unusual acid esters, e.g., 2E,11Z-C18:2-PCE. The latter served as a precursor of the major AHL of D. shibae DFL-12 LuxI1, 2E,11Z-C18:2-homoserine lactone (HSL). Incubation experiments revealed that PgaI2 accepts all substrates except C4 and C20-PCE. Competition experiments demonstrated a preference of this enzyme for C10 and C12 PCEs. In contrast, the LuxI enzymes of D. shibae are more selective. While 2E,11Z-C18:2-PCE is preferentially accepted by LuxI1, all other PCEs were not, except for the shorter, saturated C10-C14-PCEs. The AHL synthase LuxI2 accepted only C14 PCE and 3-hydroxydecanoyl-PCE. In summary, chain-length selectivity in AHLs can vary between different AHL enzymes. Both, a broad substrate acceptance and tuned specificity occur in the investigated enzymes.
A solid-phase synthetic route to N-acylated α-alkyl-D,L-homoserine lactones
Ali, Ahmed I. M.,O'Donnell, Martin J.,Samaritoni, J. Geno,Scott, William L.
supporting information, (2020/09/04)
A synthetic route to N-acylated α-alkyl-D,L-homoserine lactones was established using solid-phase unnatural peptide synthesis (UPS) and combinatorial chemistry. The application of UPS methodology allowed access to racemic N-acylated homoserine lactones (D,L-AHLs) and their α-alkyl structural analogs (α-R1-D,L-AHLs). The synthesis and characterization of a library of five D,L-AHLs and ten α-R1-D,L-AHLs prepared from resin-bound amino acids is reported.
Enzymatic Method for N-Acyl Homoserine Lactones Synthesis Using Immobilized Candida antarctica Lipase
Vázquez-Martínez, Juan,Nieto-álvarez, Edgar,Ramírez-Chávez, Enrique,Molina-Torres, Jorge
, p. 62 - 67 (2017/12/18)
Abstract: An enzymatic method to produce N-acyl homoserine lactones (AHLs) is described. This report represents the first example of the synthesis of bioactive AHLs using immobilized Candida antarctica lipase as the catalyst. The reaction yields, evaluate
Identification and Quantification of N-Acyl Homoserine Lactones Involved in Bacterial Communication by Small-Scale Synthesis of Internal Standards and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry
Leipert, Jan,Treitz, Christian,Leippe, Matthias,Tholey, Andreas
, p. 2538 - 2547 (2017/12/12)
N-acyl homoserine lactones (AHL) are small signal molecules involved in the quorum sensing of many gram-negative bacteria, and play an important role in biofilm formation and pathogenesis. Present analytical methods for identification and quantification of AHL require time-consuming sample preparation steps and are hampered by the lack of appropriate standards. By aiming at a fast and straightforward method for AHL analytics, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Suitable MALDI matrices, including crystalline and ionic liquid matrices, were tested and the fragmentation of different AHL in collision-induced dissociation MS/MS was studied, providing information about characteristic marker fragments ions. Employing small-scale synthesis protocols, we established a versatile and cost-efficient procedure for fast generation of isotope-labeled AHL standards, which can be used without extensive purification and yielded accurate standard curves. Quantitative analysis was possible in the low pico-molar range, with lower limits of quantification reaching from 1 to 5 pmol for different AHL. The developed methodology was successfully applied in a quantitative MALDI MS analysis of low-volume culture supernatants of Pseudomonas aeruginosa. [Figure not available: see fulltext.].
Molecular insights into the impact of oxidative stress on the quorum-sensing regulator protein LasR
Kafle, Prapti,Amoh, Amanda N.,Reaves, Jocelyn M.,Suneby, Emma G.,Tutunjian, Kathryn A.,Tyson, Reed L.,Schneider, Tanya L.
, p. 11776 - 11786 (2016/06/09)
The LasR regulator protein functions at the top of the Pseudomonas aeruginosa quorum-sensing hierarchy and is implicated in promoting bacterial virulence. Of note is recent evidence that this transcription factor may also respond to oxidative stress. Here, all cysteines in LasR were inspected to deduce their redox sensitivity and to probe the connection between stress response and LasR activity using purified LasR and individual LasR domains. Cys79 in the ligand binding domain of LasR appears to be important for ligand recognition and folding of this domain to potentiate DNA binding but does not seem to be sensitive to oxidative stress when bound to its native ligand. Two cysteines in the DNA binding domain of LasR do form a disulfide bond when treated with hydrogen peroxide, and formation of this Cys201-Cys203 disulfide bond appears to disrupt the DNA binding activity of the transcription factor. Mutagenesis of either of these cysteines leads to expression of a protein that no longer binds DNA. A cell-based reporter assay linking LasR function with β-galactosidase activity gave results consistent with those obtained with purified LasR. This work provides a possible mechanism for oxidative stress response by LasR and indicates that multiple cysteines within the protein may prove to be useful targets for disabling its activity.
Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators
Syrpas, Michail,Ruysbergh, Ewout,Stevens, Christian V.,De Kimpe, Norbert,Mangelinckx, Sven
, p. 2539 - 2549 (2015/02/19)
Novel N-α-haloacylated homoserine lactones, in which a halogen atom was introduced at the α-position of the carbonyl function of the N - acyl chain, have been studied as quorum sensing (QS) modulators and compared with a library of natural N - acylated homoserine lactones (AHLs). The series of novel analogues consists of α-chloro, α-bromo and α-iodo AHL analogues. Furthermore, the biological QS activity of the synthetic AHL analogues compared to the natural AHLs was evaluated. Halogenated analogues demonstrated a reduced activity in the Escherichia coli JB523 bioassay, with the α-iodo lactones being the less active ones and the α-chloro AHLs the most potent QS agonists. Most of the α-haloacylated analogues did not exhibit a significant reduction when tested in the QS inhibition test. Therefore, these novel analogues could be utilized as chemical probes for QS structure-activity studies.
Deuterium and tritium labelling of N-acyl-L-homoserine lactones (AHLs) by catalytic reduction of a double bond in the layer-by-layer method
Jakubczyk, Dorota,Merle, Christian,Brenner-Weiss, Gerald,Luy, Burkhard,Braese, Stefan
, p. 5323 - 5330 (2013/09/02)
N-Acyl-L-homoserine lactones (AHLs) are signalling molecules found in Gram-negative bacteria that enable bacteria to communicate with each other through quorum sensing and with their eukaryotic host cells through inter-kingdom signalling. Very little is known about inter-kingdom signalling mechanisms. Deuterium- and tritium-labelled AHLs were synthesized in an effort to detect the cellular distribution and monitor the membrane transport of AHLs. Most tritium labelling methods use tritium gas, which is difficult to handle, however, here we present a novel, gas-free method with which to obtain deuterium- and tritium-label terminally unsaturated AHLs through catalytic reduction of the double bond. This uncommon double bond reduction employs either sodium borohydride-[2H] or sodium borohydride-[3H] and is performed in the presence of palladium(II) acetate, which acts as a catalyst in the unique layer-by-layer system. Moreover, detailed NMR analysis of the resulting isotopologues is presented. A novel, gas-free method of deuterium- and tritium-labelling of terminally unsaturated AHLs is described. The catalytic reduction of the double bond by sodium borohydrides is performed in the presence of palladium(II) acetate, which acts as a catalyst in the unique layer-by-layer system. Copyright
Robust routes for the synthesis of N-acylated-l-homoserine lactone (AHL) quorum sensing molecules with high levels of enantiomeric purity
Hodgkinson, James T.,Galloway, Warren R.J.D.,Casoli, Mariangela,Keane, Harriet,Su, Xianbin,Salmond, George P.C.,Welch, Martin,Spring, David R.
supporting information; experimental part, p. 3291 - 3294 (2011/06/28)
The ready availability of native quorum sensing molecules and related structural analogues is of significant biological interest in the development of methods to manipulate bacterial quorum sensing systems in a useful fashion. In this Letter we report robust routes for the synthesis of a range of N-acylated-l-homoserine lactone (AHL) quorum sensing molecules. Crucially, we have analysed the enantiopurity of the final AHLs and in all cases, excellent levels were observed.
Efficient synthesis and evaluation of quorum-sensing modulators using small molecule macroarrays
Praneenararat, Thanlt,Geske, Grant D.,Blackwell, Helen E.
supporting information; experimental part, p. 4600 - 4603 (2009/12/09)
A method for the synthesis of small molecule macroarrays of N-acylated L-homoserlne lactones (AHLs) Is reported. A focused library of AHLs was constructed, and the macroarray platform was found to be compatible with both solution and agar-overlay assays u
INHIBITORS OF BIOFILM FORMATION OF GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA
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Page/Page column 46-47; 51-52, (2009/07/18)
The present invention relates to the use of compounds as broad spectrum inhibitors of bacterial biofilm formation. In particular the invention refers to a family of compounds that block the quorum sensing system of Gram-negative and Gram-positive bacteria, a process for their manufacture, pharmaceutical compositions containing them and to their use for the treatment and prevention of bacterial damages and diseases, in particular for diseases where there is an advantage in inhibiting quorum sensing regulated phenotypes of pathogens.
