Quorum-sensing cross talk:: isolation and chemical characterization of cyclic dipeptides from Pseudomonas aeruginosa and other Gram-negative bacteria
Quorum-sensing cross talk:: isolation and chemical characterization of cyclic dipeptides from Pseudomonas aeruginosa and other Gram-negative bacteria
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DOI：
10.1046/j.1365-2958.1999.01577.x
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发表时间：
1999-09-01
影响因子：
3.6
通讯作者：
Williams, P
中科院分区：
文献类型：
--
作者：
Holden, MTG;Chhabra, SR;Williams, P
在铜绿假单胞菌培养上清中，我们鉴定了两种能够激活N-酰基高丝氨酸内酯（阿勒）生物传感器的化合物，质谱和核磁共振谱表明，这两种化合物不是AHL，而是二酮哌嗪（DKP）、环（Delta Ala-L-瓦尔）和环（L-Pro-L-Tyr）。在奇异变形杆菌、弗氏柠檬酸杆菌和成团肠杆菌的无细胞上清液中也发现了这些化合物[仅环（Delta Ala-L-瓦尔）]。虽然荧光假单胞菌和产碱假单胞菌中均不存在这两种DKP，但我们从这两种假单胞菌中分离出第三种DKP，其化学特征为环状DKP。（L-Phe-L-Pro），使用基于LuxR的阿勒生物传感器的剂量-响应曲线表明，（Δ Ala-L-瓦尔），环状（L-Pro-L-Tyr）和环（L-Phe-L-Pro）以浓度依赖性方式激活生物传感器，尽管浓度比天然活化剂N-（3-氧代己酰基）-L-高丝氨酸内酯（3-oxo-C6-HSL），竞争研究表明，（Δ Ala-L-瓦尔），环状（L-Pro-L-Tyr）和环（L-Phe-L-Pro）拮抗3-oxo-C6-HSL介导的生物发光诱导，表明这些DKP可能竞争相同的LuxR结合位点。类似地，发现DKPs能够激活或拮抗其他基于LuxR的群体感应系统，例如Serratia acquifaciens的N-丁酰高丝氨酸内酯依赖性群集运动。虽然这些DKP的生理作用尚未确定，但它们的活性表明细菌信号系统之间存在串扰。
In cell-free Pseudomonas aeruginosa culture supernatants, we identified two compounds capable of activating an N-acylhomoserine lactone (AHL) biosensor, Mass spectrometry and NMR spectroscopy revealed that these compounds were not AHLs but the dike-topiperazines (DKPs), cyclo(Delta Ala-L-Val) and cyclo(L-Pro-L-Tyr) respectively. These compounds were also found in cell-free supernatants from Proteus mirabilis, Citrobacter freundii and Enterobacter agglomerans [cyclo(Delta Ala-L-Val) only]. Although both DKPs were absent from Pseudomonas fluorescens and Pseudomonas alcaligenes, we isolated, from both pseudomonads, a third DKP, which was chemically characterized as cyclo(L-Phe-L-Pro), Dose-response curves using a LuxR-based AHL biosensor indicated that cyclo(Delta Ala-L-Val), cyclo(L-Pro-L-Tyr) and cyclo(L-Phe-L-Pro) activate the biosensor in a concentration-dependent manner, albeit at much higher concentrations than the natural activator N-(3-oxohexanoyi)-L-homoserine lactone (3-oxo-C6-HSL), Competition studies showed that cyclo(Delta Ala-L-Val), cyclo(L-Pro-L-Tyr) and cyclo(L-Phe-L-Pro) antagonize the 3-oxo-C6-HSL-mediated induction of bioluminescence, suggesting that these DKPs may compete for the same LuxR-binding site. Similarly, DKPs were found to be capable of activating or antagonizing other LuxR-based quorum-sensing systems, such as the N-butanoylhomoserine lactone-dependent swarming motility of Serratia liquefaciens. Although the physiological role of these DKPs has yet to be established, their activity suggests the existence of cross talk among bacterial signalling systems.