All-or-none membrane permeabilization by fengycin-type lipopeptides from Bacillus subtilis QST713
All-or-none membrane permeabilization by fengycin-type lipopeptides from Bacillus subtilis QST713
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DOI：
10.1016/j.bbamem.2011.04.008
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发表时间：
2011-08-01
影响因子：
3.4
通讯作者：
Heerklotz, Heiko
中科院分区：
文献类型：
--
作者：
Patel, Hiren;Tscheka, Clemens;Heerklotz, Heiko
枯草芽孢杆菌QST713的杀菌活性已被用于作物对多种病原菌的高效和环境安全保护。它主要是基于丰霉素(FES)、表面蛋白和伊图林家族的环状脂肽的产生。天然FeS的混合群体形成胶束，使单独的FeS溶解，如agrastatin 1(AS1)，否则这些FeS本身是不能溶解的。基于荧光寿命的钙黄绿素外流测量和低温电子显微镜显示，这些FES显示了独特的膜通透性场景。FeS与脂类的不相容可能会在10%的囊泡中形成孔洞，在大约1µM的游离FE处，在15%的囊泡中形成孔。我们解释了为什么这种有限的、全有或全无的渗漏仍然可以解释为什么几乎所有真菌都被杀死，而相同程度的分级囊泡渗漏可能与生物学无关。然后，AS1的结晶和plipastatins的胶束化导致15%的截断渗漏，这可能调节FeS的生物活性，保护芽孢杆菌和植物膜。事实上，FE胶束只增溶约10摩尔-%的流体脂，这一事实类似于洗涤剂的耐受性。皇冠版权(C)2011由爱思唯尔出版。版权所有。
The fungicidal activity of Bacillus subtilis QST713 has been utilized for the highly effective and environmentally safe protection of crops against a variety of pathogens. It is based mainly on the production of cyclic lipopeptides of the fengycin (FEs), surfactin, and iturin families. The mixed population of native FEs forms micelles which solubilize individual FEs such as agrastatin 1 (AS1) that are otherwise rather insoluble on their own. Fluorescence lifetime-based calcein efflux measurements and cryo transmission electron microscopy show that these FEs show a unique scenario of membrane permeabilization. Poor miscibility of FEs with lipid probably promotes the formation of pores in 10% of the vesicles at only approximate to 1 mu M free FE and in 15% of the vesicles at 10 mu M. We explain why this limited, all-or-none leakage could nevertheless account for the killing of virtually all fungi whereas the same extent of graded vesicle leakage may be biologically irrelevant. Then, crystallization of AS1 and micellization of plipastatins cause a cut-off in leakage at 15% that might regulate the biological activity of FEs, protecting Bacillus and plant membranes. The fact that FE micelles solubilize only about 10 mol-% fluid lipid resembles the behavior of detergent resistance. Crown Copyright (C) 2011 Published by Elsevier By. All rights reserved.