Cyclic voltammetric, fluorescence and biological analysis of purified aeruginosin A, a secreted red pigment of Pseudomonas aeruginosa PAO1
Cyclic voltammetric, fluorescence and biological analysis of purified aeruginosin A, a secreted red pigment of Pseudomonas aeruginosa PAO1
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DOI：
10.1099/mic.0.065235-0
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发表时间：
2013-08-01
期刊：
影响因子：
2.8
通讯作者：
Hassett, Daniel J.
中科院分区：
文献类型：
--
作者：
Abu, Eme A.;Su, Shengchang;Hassett, Daniel J.
机会致病菌铜绿假瘤在体外培养和体内烧伤创面定植以及囊性纤维化（CF）患者气道中产生多种色素。一种色素是一种深“梅洛”色的化合物，被称为铜绿素a （AA）。然而，P. aeruginosa的红色色素通常被统称为pyorubrin，其化学成分未知。在这里，我们用质谱法纯化和确认了AA（2-氨基-6-羧基-10-甲基吩嗪甜菜碱），并通过循环伏安法和光谱（以及荧光）特性评估了它的物理化学性质。在生理ph下进行的实验中，AA在500至-200 mV的电位范围内在玻碳电极上表现出可逆的电化学反应。电化学阳极和阴极峰值电流分别为327和-360 mV，相对于Ag/AgCl的形式还原电位为-343.5 mV。AA在516 nm处吸收，606 nm处荧光。荧光光谱电化学结果表明，荧光最强的是亲本或氧化态荧光。铜绿假单胞菌AA的产生受细胞间信号系统（称为群体感应）的rhl组分的控制，并且在固定生长阶段产生最多。然而，与其下游的蓝色氧化还原活性毒素pyocyanin不同，AA对耐甲氧西林金黄色葡萄球菌USA300、大肠杆菌dh5 - α或人角质形成细胞没有不良影响。最后，我们对AA的潜在商业用途提出了一些看法。
The opportunistic pathogen Pseudomomas aeruginosa produces multiple pigments during in vitro culture and in vivo during colonization of burn wounds and in the airways of cystic fibrosis (CF) patients. One pigment is a deep 'merlot'-coloured compound known as aeruginosin A (AA). However, the red pigment(s) of P. aeruginosa are often collectively called pyorubrin, of which there is no known chemical composition. Here, we purified and confirmed by MS and assessed the physicochemical properties of AA (2-amino-6-carboxy-10-methylphenazinium betaine) by first focusing on its ability to redox-cycle using cyclic voltammetry and its spectroscopic (as well as fluorescent) properties, experiments that were conducted at physiological pH. AA exhibited reversible electrochemistry at a glassy carbon electrode within a potential range of 500 to -200 mV. Electrochemical anodic and cathodic peak currents were observed at 327 and -360 mV, respectively, with a low formal reduction potential of -343.5 mV versus Ag/AgCl. AA absorbed at 516 nm and fluoresced at 606 nm. Results from the spectro-electrochemistry of pyorubrin revealed that its strongest fluorescence was in its parent or oxidized form. Production of AA by P. aeruginosa was found to be controlled by the rhl component of the intercellular signalling system known as quorum sensing and was produced maximally during the stationary growth phase. However, unlike its downstream blue redox-active toxin, pyocyanin, AA had no adverse effects on methicillin-resistant Staphylococcus aureus USA300, Escherichia coli DH5-alpha or human keratinocytes. We close with some thoughts on the potential commercial use(s) of AA.