利用原位X射线散射研究神经酰胺E与海藻糖的相互作用

Interaction between Trehalose and Ceramide Studied by in-situ X-ray Scattering

海藻糖和神经酰胺在皮肤保湿中具有重要作用。利用原位X射线散射设备,研究了在干燥和升降温过程中海藻糖与神经酰胺之间的分子相互作用。结果表明,在海藻糖的存在下,神经酰胺E与细胞膜脂分子一样难以失水而延缓了结晶过程。反之,神经酰胺也抑制了海藻糖在干燥过程中结晶,从而延缓了水分挥发。此外,在海藻糖的存在下,冷冻干燥的神经酰胺乳液样品加热至105℃再降至室温,形成了皮肤中广泛存在的正交晶相和液晶相共存的结构,很好地模拟了皮肤细胞间脂层的相结构。发现海藻糖代替了角质层中的其它成分,保护神经酰胺分子以真实皮肤中的方式排列。

Trehalose and ceramide both play important roles in retaining skin water.With an X-ray scattering instrument,we studied the interaction between ceramide E and trehalose systematically in the course of drying and heating-cooling scan.It was found that ceramide E,similar to lipids in membrane,was difficult to crystallize in the presence of trehalose.Similarly,ceramide also suppresses the crystallization of trehalose during drying and therefore prevents water loose.Furthermore,after cooling from 105 ℃ to room temperature with the presence of trehalose,the freeze-dried ceramide formed a structure similar to that of stratum corneum in human skin in which both liquid and orthorhombic crystal exist.It is the first time to be found that trehalose,in stead of other components in skin,help ceramide to be organized by the form in the real human skin.