Quorum quenching by an N-acyl-homoserine lactone acylase from Pseudomonas aeruginosa PAO1
Quorum quenching by an N-acyl-homoserine lactone acylase from Pseudomonas aeruginosa PAO1
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DOI：
10.1128/iai.74.3.1673-1682.2006
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发表时间：
2006-03-01
影响因子：
3.1
通讯作者：
Quax, WJ
中科院分区：
文献类型：
--
作者：
Sio, CF;Otten, LG;Quax, WJ
铜绿假单胞菌PAO 1的毒力受N-酰基高丝氨酸内酯（阿勒）依赖的群体感应系统控制。在铜绿假单胞菌PAO 1基因组中推定的酰基转移酶基因的功能分析期间，发现PA 2385基因编码一种酰基转移酶，该酰基转移酶从AHL依赖性群体感应信号分子的高丝氨酸内酯（HSL）核中去除脂肪酸侧链。分析表明，该酰化酶的翻译后加工过程和水解反应类型与β-内酰胺酰化酶相似，表明该蛋白属于N-末端亲核水解酶超家族。在生物测定中，纯化的酰化酶显示出在生理相关的低浓度下降解侧链长度为11至14个碳的AHLs。侧链3'位的取代基不影响活性，表明宽范围的阿勒群体猝灭活性。在铜绿假单胞菌PAO 1的两种主要阿勒信号分子N-丁酰基-L-高丝氨酸内酯（C-4-HSL）和N-（3-氧代十二烷酰基）-L-高丝氨酸内酯（3-氧代-C-12-HSL）中，只有3-氧代-C-12-HSL被酶降解。向铜绿假单胞菌PAO 1培养物中添加纯化的蛋白质完全抑制了3-氧代-C-12-HSL的积累和信号分子2-庚基-3-羟基-4（1H）-喹诺酮的产生，并减少了毒力因子弹性蛋白酶和绿脓菌素的产生。当PA 2385基因在铜绿假单胞菌中过表达时，也获得了类似的结果。这些结果表明，该蛋白具有原位群体淬灭活性。群体淬灭阿勒酰化酶可能使铜绿假单胞菌PAO 1能够调节其自身的群体感应依赖性致病潜力，此外，还为新型抗假单胞菌疗法提供了可能性。
The virulence of the opportunistic human pathogen Pseudomonas aeruginosa PAO1 is controlled by an N-acyl-homoserine lactone (AHL)-dependent quorum-sensing system. During functional analysis of putative acylase genes in the P. aeruginosa PAO1 genome, the PA2385 gene was found to encode an acylase that removes the fatty acid side chain from the homoserine lactone (HSL) nucleus of AHL-dependent quorum-sensing signal molecules. Analysis showed that the posttranslational processing of the acylase and the hydrolysis reaction type are similar to those of the beta-lactam acylases, strongly suggesting that the PA2385 protein is a member of the N-terminal nucleophile hydrolase superfamily. In a bioassay, the purified acylase was shown to degrade AHLs with side chains ranging in length from 11 to 14 carbons at physiologically relevant low concentrations. The substituent at the 3' position of the side chain did not affect activity, indicating broad-range AHL quorum-quenching activity. Of the two main AHL signal molecules of A aeruginosa PAO1, N-butanoyl-L-homoserine lactone (C-4-HSL) and N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C-12-HSL), only 3-oxo-C-12-HSL is degraded by the enzyme. Addition of the purified protein to P. aeruginosa PAO1 cultures completely inhibited accumulation of 3-oxo-C-12-HSL and production of the signal molecule 2-heptyl-3-hydroxy-4(1H)-quinolone and reduced production of the virulence factors elastase and pyocyanin. Similar results were obtained when the PA2385 gene was overexpressed in P. aeruginosa. These results demonstrate that the protein has in situ quorum-quenching activity. The quorum-quenching AHL acylase may enable P. aeruginosa PAO1 to modulate its own quorum-sensing-dependent pathogenic potential and, moreover, offers possibilities for novel antipseudomonal therapies.