A Classical Molecular Dynamics Simulation Study of Interfacial and Bulk Solution Aggregation Properties of Dirhamnolipids.
A Classical Molecular Dynamics Simulation Study of Interfacial and Bulk Solution Aggregation Properties of Dirhamnolipids.
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Dirhamnolipids 界面和本体溶液聚集特性的经典分子动力学模拟研究。
DOI：
10.1021/acs.jpcb.9b08800
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Schwartz,StevenD
中科院分区：
文献类型：
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作者：
Luft,CharlesM;Munusamy,Elango;Pemberton,JeanneE;Schwartz,StevenD
鼠李糖脂是一类独特的生物表面活性剂，由铜绿假单胞菌产生。这些分子表现出高水平的表面活性和生物降解性。本文采用分子动力学模拟方法研究了非离子型双糖脂在空气-水界面和散装水中的分子动力学特性。对界面模拟和溶液模拟进行了详细的结构分析。本文系统地比较了前人在空气-水界面和散装水中对单糖脂的研究。鼠李糖脂中第二个鼠李糖基团的存在对空气-水界面的聚集没有明显的影响。随着分子量的增加，双鼠糖脂在空气-水界面处比单鼠糖脂具有更大的比表面积。然而，鼠李糖脂在散装水中的聚集受到第二鼠李糖组存在的影响。双鼠李糖脂在~ N22附近聚集成胶束结构，比单鼠李糖脂聚集数~ N40低。双糖脂的疏水组分被增强以平衡较高的亲水组分。烷基链长度的增加表明疏水组分的增强支持胶束聚集体的形成，达到~ N30及以上，这在烷基链长度较短的双糖脂中没有观察到。
The rhamnolipids are a unique class of biosurfactants produced by the bacteriaPseudomonas aeruginosa. These molecules display a high level of surface activity as well as biodegradability. In this study nonionic dirhamnolipid was investigated by utilizing molecular dynamics simulation at the air–water interface as well as in bulk water. Detailed structural analysis is presented for both the interfacial simulations and the simulations in solution. A systematic comparison was made between our previous work on the monorhamnolipid at the air–water interface and in bulk water. The presence of a second rhamnose group in dirhamnolipid did not show any significant change in the aggregation at the air–water interface. An increase in the molecular weight resulted in the larger surface area per monomer for dirhamnolipid compared to monorhamnolipid at the air–water interface. However, aggregation of dirhamnolipid in bulk water was affected by the presence of a second rhamnose group. Dirhamnolipid aggregates into micellar structure around ∼N22 which was lower than the monorhamnolipid aggregation number ∼N40. The hydrophobic component of the dirhamnolipid was enhanced to balance the higher hydrophilic component. An increase in alkyl chain length has shown that the enhanced hydrophobic component supports the formation of micellar aggregates up to ∼N30 and above, which was not observed in dirhamnolipid with a shorter alkyl chain length.