Packing density of glycolipid biosurfactant monolayers give a significant effect on their binding affinity toward immunoglobulin G.
Packing density of glycolipid biosurfactant monolayers give a significant effect on their binding affinity toward immunoglobulin G.
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DOI：
10.5650/jos.57.415
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发表时间：
2008
影响因子：
1.5
通讯作者：
T. Imura;Yuma Masuda;S. Ito;Wannasiri Worakitkanchanakul;Tomotake Morita;T. Fukuoka;H. Sakai;M. Abe-M.
中科院分区：
文献类型：
--
作者：
T. Imura;Yuma Masuda;S. Ito;Wannasiri Worakitkanchanakul;Tomotake Morita;T. Fukuoka;H. Sakai;M. Abe-M.
甘露糖脂-A(Mel-A)是一种最有发展前景的糖脂生物表面活性剂，由假酵母菌大量生产。MEL-A不仅具有良好的自组装性能，而且与人免疫球蛋白G(HIGG)具有很高的结合亲和力。本研究以肉豆蔻酸甲酯[MEL-A(M)]、橄榄油[MEL-A(O)]和大豆油[MEL-A(S)]为原料制备了三种MEL-A，并利用表面等离子体共振法和表面积(Pi)-面积(A)等温线研究了各MEL-A单层的界面性质对其与HIGG结合亲和力的影响。经GC-MS分析，所有Mel-A中的主要脂肪酸为C(8)和C(10)酸，不饱和脂肪酸含量分别为0%、9.1%和46.3%(S)。有趣的是，酸含量对它们的结合亲和力有显著影响，MEL-A(O)的单层结合亲和力高于MEL-A(M)和MEL-A(S)。此外，以1/1摩尔比制备的MEL-A(O)/MEL-A(S)混合单层膜具有最高的结合亲和力，其不饱和脂肪酸含量为27.8%。在空气/水界面，MEL-A(O)单分子膜在13℃下发生了从液体凝聚单分子膜到液体膨胀单分子膜的相变，单分子面积显著扩大到13℃以上，而HIGG结合在液体膨胀单分子膜上的量远高于与液体凝聚单分子膜结合的量。因此，MEL-A与HIGG的结合亲和力可能与单层堆积密度密切相关，并可能部分受温度控制。
Mannosylerythritol lipid-A (MEL-A) is one of the most promising glycolipid biosurfactants, and abundantly produced by Pseudozyma yeasts. MEL-A gives not only excellent self-assembling properties but also a high binding affinity toward human immunoglobulin G (HIgG). In this study, three kinds of MEL-A were prepared from methyl myristate [MEL-A (m)], olive oil [MEL-A (o)], and soybean oil [MEL-A (s)], and the effect of interfacial properties of each MEL-A monolayer on the binding affinity toward HIgG was investigated using surface plasmon resonance (SPR) and the measurement of surface pressure (pi)-area (A) isotherms. Based on GC-MS analysis, the main fatty acids were C(8) and C(10) acids in all MEL-A, and the content of unsaturated fatty acids was 0% for MEL-A (m), 9.1% for MEL-A (o), 46.3% for MEL-A (s), respectively. Interestingly, the acid content significantly influenced on their binding affinity, and the monolayer of MEL-A (o) gave a higher binding affinity than that of MEL-A (m) and MEL-A (s). Moreover, the mixed MEL-A (o)/ MEL-A (s) monolayer prepared from 1/1 molar ratio, which comprised of 27.8% of unsaturated fatty acids, indicated the highest binding affinity. At the air/water interface, MEL-A (o) monolayer exhibited a phase transition at 13 degrees C from a liquid condensed monolayer to a liquid expanded monolayer, and the area per molecule significantly expanded above 13 degrees C, while the amount of HIgG bound to the liquid expanded monolayer was much higher than that bound to liquid condensed monolayer. The binding affinity of MEL-A toward HIgG is thus likely to closely relate to the monolayer packing density, and may be partly controlled by temperature.