Solubility and bioactivity of the Pseudomonas quinolone signal are increased by a Pseudomonas aeruginosa-produced surfactant
Solubility and bioactivity of the Pseudomonas quinolone signal are increased by a Pseudomonas aeruginosa-produced surfactant
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DOI：
10.1128/iai.73.2.878-882.2005
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发表时间：
2005-02-01
影响因子：
3.1
通讯作者：
Pesci, EC
中科院分区：
文献类型：
--
作者：
Calfee, MW;Shelton, JG;Pesci, EC
铜绿假单胞菌是一种革兰氏阴性细菌，会导致免疫功能低下个体和囊性纤维化患者严重感染。这种机会性病原体通过三种细胞间信号的活性来控制其许多毒力因子和细胞功能：N-(3-氧代十二酰基)-L-高丝氨酸内酯、N-丁酰-L-高丝氨酸内酯和假单胞菌喹诺酮信号 (PQS)。这些信号的活性取决于它们在铜绿假单胞菌恰好存在的水溶液中溶解和自由扩散的能力。尽管如此，我们的数据表明 PQS 在水溶液中相对不溶，这使我们推测铜绿假单胞菌可能产生 PQS 溶解因子。在本报告中，我们表明铜绿假单胞菌产生的生物表面活性剂鼠李糖脂大大提高了 PQS 在水溶液中的溶解度。通过基因诱导测定和细胞凋亡测定检测，PQS 溶解度的增强导致 PQS 生物活性增加。这是首次证明细菌表面活性剂在细胞间信号的溶解和生物活性中的重要性。
Pseudomonas aeruginosa is a gram-negative bacterium that causes serious infections in immunocompromised individuals and cystic fibrosis patients. This opportunistic pathogen controls many of its virulence factors and cellular functions through the activity of three cell-to-cell signals, N-(3-oxododecanoyl)-L-homoserine lactone, N-butyryi-L-homoserine lactone, and the Pseudomonas quinolone signal (PQS). The activity of these signals is dependent upon their ability to dissolve in and freely diffuse through the aqueous solution in which P. aeruginosa happens to reside. Despite this, our data indicated that PQS was relatively insoluble in aqueous solutions, which led us to postulate that P. aeruginosa could be producing a PQS-solubilizing factor. In this report, we show that the P. aeruginosa-produced biosurfactant rhamnolipid greatly enhances the solubility of PQS in aqueous solutions. The enhanced solubility of PQS led to an increase in PQS bioactivity, as measured by both a gene induction assay and an apoptosis assay. This is the first demonstration of the importance of a bacterial surfactant in the solubilization and bioactivity of a cell-to-cell signal.