Effect of lipoteichoic acid on thermotropic membrane properties
Effect of lipoteichoic acid on thermotropic membrane properties
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DOI：
10.1128/jb.179.9.2879-2883.1997
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发表时间：
1997-05-01
影响因子：
3.2
通讯作者：
Fischer, W
中科院分区：
文献类型：
--
作者：
Gutberlet, T;Frank, J;Fischer, W
采用差示扫描量热法研究了从金黄色葡萄球菌中分离的脂壁酸、二葡糖基二酰基甘油和磷脂酰甘油包埋在双棕榈酰基甘油-磷酸甘油囊泡中，对其热致性的影响。磷脂酰甘油的天然脂肪酸对峰展宽和摩尔热容的降低有影响，且糖脂对峰展宽和摩尔热容的影响更为明显，同时提高了主转变温度。在脂磷壁酸混合物中，观察到两个宽的主要过渡峰，可能是由于囊泡中脂磷壁酸的含量不同。两个峰都显示了转变温度的进一步升高和摩尔热容的明显下降。由于这三种两亲体的二酰基甘油部分实际上是相同的，因此热致性效应的差异必须归因于头基团的不同结构。二葡萄糖基二酰基甘油被认为是通过糖环上的羟基与磷脂邻居形成氢键来发挥额外的作用，脂磷胆酸的作用更强，表明长亲水链与囊泡表面的动态相互作用，从而稳定了膜结构。
Lipoteichoic acid, diglucosyldiacylglycerol, and phosphatidylglycerol isolated from Staphylococcus aureus were embedded in dipalmitoylglycerophosphoglycerol vesicles, and their thermotropic influence on this matrix was studied by differential scanning calorimetry. The natural fatty acids of phosphatidylglycerol effected peak broadening and a decrease in molar heat capacity, These effects were more pronounced with the glycolipid, which also increased the main transition temperature. With the lipoteichoic acid mixtures, two broad main transition peaks were observed, possibly due to different levels of lipoteichoic acid in vesicles. Both peaks showed a further upshift in transition temperatures and a pronounced decrease in molar heat capacity. Since the diacylglycerol moieties of all three amphiphiles were practically identical, the differences in the thermotropic effects have to be ascribed to the different structures of the head groups. Diglucosyldiacylglycerol is proposed to exert an additional effect by hydrogen bonding the hydroxyls of the sugar rings to their phospholipid neighbors, The stronger effect of lipoteichoic acid points to dynamic interactions of the long hydrophilic chain with the vesicle surface, which stabilize the membrane structure.