Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.79 (hormone-sensitive lipase)
 2,163 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of quorum sensing signal molecules in Pseudomonas aeruginosa, N-butanoyl-L-homoserinelactone (C4-HSL) and N-(3-oxododecanoyl)-L-homoserinelactone (3-oxo-C12-HSL) on planktonic cell resistance against hydrogen peroxide were studied. In P. aeruginosa JP2 cells with the deletion of lasI and rhlI, the viable cell concentration decreased with time and was reduced by about 4 log after 2 h of 7.5 mM H2O2 treatment, while only a 2-log reduction was found for the wild type P. aeruginosa PAO1 cells. When cultured with 20% PAO1 spent medium, P. aeruginosa JP2 showed similar hydrogen peroxide resistance to that seen in P aeruginosa PAO1. Culturing with 20% JP2 spent medium or with 10 microM C4-HSL and 20 microM 3-oxo-C12-HSL did not affect P aeruginosa JP2 cell susceptibility to hydrogen peroxide. Although both 20% PAO1 and JP2 spent media reacted with H2O2 and reduced H2O2 to 50% of the strength of the original concentration, the remaining H2O2 was still sufficient to kill P. aeruginosa JP2. These results indicate that the difference in cell resistance against H2O2 between P. aeruginosa PAO1 and JP2 was related to the existence of gene products of the lasI and rhlI systems. However, adding synthetic homoserine lactones alone did not increase P. aeruginosa JP2 cell resistance to H2O2 as seen in the experiments adding PAO1 spent medium. Determination of the detailed relation between cascade regulation in P. aeruginosa and its cell resistance to H2O2 will require further investigation.
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PMID:Effects of quorum sensing signal molecules on the hydrogen peroxide resistance against planktonic Pseudomonas aeruginosa. 1104 77

Surface adhered bacterial colonies or biofilms are an important problem in medical and food industries. Bacteria use a chemical language to monitor their quorum and to express virulence factors, which eventually help them in colonization and manifestation of an infection. The LasR-LasI and RhlR-RhlI quorum-sensing (QS) systems of Pseudomonas aeruginosa control expression of virulence factors in a population density-dependent fashion. In this study we investigated the role of synthetic analogs to RhlR-RhlI system of P. aeruginosa strains (PAO-1; wild-type and mutants JP-1, PDO-100, and JP-2) responsible for production of acyl-homoserine lactones-2; butanol homoserine lactone (AHL-2; C(4)-HSL). We synthesized double (QS1207) and single (QS0108) sulfur analogs against (C(4)-HSL; AHL-2), an autoinducer of Pseudomonas QS system. Extensive biological investigation of these analogs suggested a growth promoting activity for these analogs in Pseudomonas controlling biofilm production and exo-protease secretion. We hypothesized that these thiolactone analogs could be potentially utilized as potent drug-delivery vehicles against biofilm-producing pathogens. As a proof of principle we conjugated the single sulfur analog QS0108 with the broad-spectrum antibiotic, ciprofloxacin (QS0108-Cip). The QS analog-antibiotic conjugate was significantly more effective at disrupting both the nascent and mature biofilms of P. aeruginosa than the free antibiotic.
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PMID:Design, synthesis, and a novel application of quorum-sensing agonists as potential drug-delivery vehicles. 2088 84