Pressure-temperature phase behaviour of natural sphingomyelin extracts
Pressure-temperature phase behaviour of natural sphingomyelin extracts
复制标题
天然鞘磷脂提取物的压力-温度相行为
作者：
Shaw K
鞘磷脂是哺乳动物细胞中天然存在的唯一鞘脂，可形成神经周围髓鞘总磷脂含量的高达50%。它主要具有长的饱和酰基链，具有相对高的链解链温度，并与脂质微区的形成密切相关。在这里，溶致相行为的鞘磷脂从三个不同的天然来源（牛脑，蛋黄和牛奶）在过量的水研究作为一个函数的温度和压力的小角和广角X-射线散射，和固态NMR。三种脂质提取物的不同烃链长度分布导致其凝胶相结构的显著差异;牛脑和蛋黄鞘磷脂均可形成涟漪凝胶相，但牛奶鞘磷脂由于其较长烃链组分中的高度链错配而形成叉指型凝胶相。
Sphingomyelin is the only sphingolipid occurring naturally in mammalian cells and can form up to 50% of the total phospholipid content of the myelin sheath which surrounds nerves. Having predominantly long, saturated acyl chains, it has a relatively high chain melting temperature and has been strongly associated with formation of lipid microdomains. Here, the lyotropic phase behaviour of sphingomyelin from three different natural sources (bovine brain, egg yolk and milk) in excess water is studied as a function of temperature and pressure by small- and wide-angle X-ray scattering, and solid state NMR. The different hydrocarbon chain length distributions of the three lipid extracts results in significant differences in their gel phase structure; both the bovine brain and egg yolk sphingomyelins can form a ripple gel phase but milk sphingomyelin forms an interdigitated gel phase due to the high degree of chain mismatch in its longer hydrocarbon chain components.