Effects on membrane lateral pressure suggest permeation mechanisms for bacterial quorum signaling molecules.
Effects on membrane lateral pressure suggest permeation mechanisms for bacterial quorum signaling molecules.
复制标题
DOI：
10.1021/bi200684z
复制
发表时间：
2011-08-16
期刊：
影响因子：
2.9
通讯作者：
Sukharev, Sergei
中科院分区：
文献类型：
--
作者：
Kamaraju, Kishore;Smith, Jacqueline;Wang, Jingxin;Roy, Varnika;Sintim, Herman O.;Bentley, William E.;Sukharev, Sergei
群体感应是微生物群落中由小分泌分子（自诱导剂）介导的“社会”行为的一个复杂例子。对于许多人来说，膜渗透的机制仍然难以捉摸。在这里，我们根据三种天然自诱导剂和五种合成类似物的极性、表面活性、对脂质单层的亲和力以及诱导细菌张力激活通道 MscS 感测的大肠杆菌内膜侧向压力变化的能力，对膜渗透性进行评估。 AI-1（N-（3-氧代癸酰基）-L-高丝氨酸内酯）具有表面活性，它能牢固地插入脂质单层中，表明对膜有很强的倾向。当从细胞质侧呈现到膜斑块时，AI-1 由于插入细胞质小叶然后重新分布到另一侧，而短暂地将 MscS 的激活曲线移向更高的张力。吲哚在空气-水界面处没有显示出可检测到的表面活性，但在单层中产生适度的侧压增加，并且能够有效地改变MscS的激活曲线，证明了连续添加时的瞬态。 AI-2（4,5-二羟基-2,3-戊二酮，DPD）在界面处表现出很少的活性，相应地对MscS激活没有影响。经过异丁基、己基或庚基链的化学修饰后，AI-2表现出很强的表面活性。己基，尤其是庚基 AI-2 诱导了 MScS 激活曲线的剧烈瞬态变化。数据强烈表明 AI-1 和吲哚均可直接透过膜。 AI-2 更亲水，对脂质的亲和力较低，因此需要运输系统，而 AI-2 的烷基类似物应直接渗透膜。
Quorum sensing is an intricate example of ‘social’ behavior in microbial communities mediated by small secreted molecules (autoinducers). The mechanisms of membrane permeation remain elusive for many of them. Here we present the assessment of membrane permeability for three natural autoinducers and five synthetic analogs based on their polarity, surface activity, affinity for lipid monolayers and ability to induce lateral pressure changes in the inner E. coli membrane sensed by the bacterial tension-activated channel MscS. AI-1 (N-(3-Oxodecanoyl)-L-homoserine lactone) is surface-active, it robustly inserts into lipid monolayers, indicating strong propensity toward membranes. When presented to membrane patches from the cytoplasmic side, AI-1 transiently shifts MscS’s activation curve toward higher tensions due to intercalation into the cytoplasmic leaflet followed by redistribution to the opposite side. Indole showed no detectable surface activity at the air-water interface, but produced a moderate increase of lateral pressure in monolayers and was potent at shifting activation curves of MscS, demonstrating transients on sequential additions. AI-2 (4,5-dihydroxy-2,3-pentanedione, DPD) showed little activity at the interfaces, correspondingly with no effect on MscS activation. After chemical modification with isobutyl, hexyl or heptyl chains, AI-2 displayed strong surface activity. Hexyl and especially heptyl AI-2 induced robust transient shifts of MscS activation curves. The data strongly suggest that both AI-1 and indole are directly permeable through the membrane. AI-2, more hydrophilic, shows low affinity toward lipids and thus requires a transport system, whereas alkyl analogs of AI-2 should permeate the membrane directly.
登录
查看更多内容
影响因子：
3.3
作者：
Gaede, HC;Yau, WM;Gawrisch, K
通讯作者：
Gawrisch, K
影响因子：
3.2
作者：
Henke, JM;Bassler, BL
通讯作者：
Bassler, BL
影响因子：
3.2
作者：
Blaser, Georg;Sanderson, John M.;Wilson, Mark R.
通讯作者：
Wilson, Mark R.
DOI：
10.1085/jgp.200910371
发表时间：
2010-06
期刊：
The Journal of general physiology
影响因子：
--
作者：
Belyy V;Kamaraju K;Akitake B;Anishkin A;Sukharev S
通讯作者：
Sukharev S
DOI：
10.1085/jgp.200409198
发表时间：
2005-02
期刊：
The Journal of general physiology
影响因子：
--
作者：
Akitake B;Anishkin A;Sukharev S
通讯作者：
Sukharev S