Alkali-earth metal bridges formed in biofilm matrices regulate the uptake of fluoroquinolone antibiotics and protect against bacterial apoptosis
Alkali-earth metal bridges formed in biofilm matrices regulate the uptake of fluoroquinolone antibiotics and protect against bacterial apoptosis
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生物膜基质中形成的碱土金属桥调节氟喹诺酮类抗生素的摄取并防止细菌凋亡
DOI：
10.1016/j.envpol.2016.09.029
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发表时间：
2017
影响因子：
8.9
通讯作者：
Gao Yanzheng
中科院分区：
文献类型：
--
作者：
Kang Fuxing;Wang Qian;Shou Weijun;Collins Chris D.;Gao Yanzheng
细菌细胞外生物膜在减轻氟喹诺酮类抗生素（FQA）污染物的毒性方面发挥着关键作用，但目前尚不清楚抗生素攻击是否可以通过与金属强化解毒效率相关的细菌一两拳策略来化解。我们的研究结果有助于分配功能的生物膜的特定结构特征，因为它们强烈地暗示了一种分子调控机制，通过该机制，在自然沃茨中自由访问的碱土金属影响细胞在水-生物膜界面的吸收。具体而言，碱土金属（Ca 2+或Mg 2+）之间的建模环丙沙星和大肠杆菌的生物膜桥的形成调节trans-biofilm运输速率的THAs向细胞（135 nm厚的生物膜）。Ca 2+和Mg 2+（0- 3.5mmol/L，CIP：1.25 μmol/L）的加入使转运率分别降低到52.4%和63.0%。计算化学分析进一步证明了生物膜色氨酸残基中的去质子化羧基作为一个主要的桥接位点，其一侧是金属，另一侧是连接到FQA的羧基和羰基的金属梁。细菌的生长速率取决于锚定位点的架桥能，这强调了在细菌抗生素抗性中在生物膜基质中形成的金属桥的环境重要性。
Bacterially extracellular biofilms play a critical role in relieving toxicity of fluoroquinolone antibiotic (FQA) pollutants, yet it is unclear whether antibiotic attack may be defused by a bacterial one-two punch strategy associated with metal-reinforced detoxification efficiency. Our findings help to assign functions to specific structural features of biofilms, as they strongly imply a molecularly regulated mechanism by which freely accessed alkali–earth metals in natural waters affect the cellular uptake of FQAs at the water-biofilm interface. Specifically, formation of alkali-earth-metal (Ca2+or Mg2+) bridge between modeling ciprofloxacin and biofilms ofEscherichia coliregulates the trans-biofilm transport rate of FQAs towards cells (135-nm-thick biofilm). As the addition of Ca2+and Mg2+(0–3.5 mmol/L, CIP: 1.25 μmol/L), the transport rates were reduced to 52.4% and 63.0%, respectively. Computational chemistry analysis further demonstrated a deprotonated carboxyl in the tryptophan residues of biofilms acted as a major bridge site, of which one side is a metal and the other is a metal girder jointly connected to the carboxyl and carbonyl of a FQA. The bacterial growth rate depends on the bridging energy at anchoring site, which underlines the environmental importance of metal bridge formed in biofilm matrices in bacterially antibiotic resistance.