用鞘磷脂作为标志分子鉴定脂筏

脂筏是质膜双层中富含鞘脂、胆固醇及特殊蛋白质的质膜微区.对其功能的研究，首先要对其进行分离和鉴定.常利用密度梯度超速离心将其分离，然后以脂筏中富含的神经节苷脂GM₁作为标志分子，利用荧光或生物素标记的霍乱毒素-B亚基进行亲和标记来鉴定脂筏.但这一鉴定方法操作复杂、费时、易对环境造成污染，所用关键试剂霍乱毒素不易获得，再加上一些组织GM₁含量甚微或不含GM₁，使其应用受到局限.为建立一个特异性高又对各种组织广泛适应的脂筏鉴定方法.对两种细胞系脂筏的脂类组分进行了分析.结果发现，可用鞘磷脂作为脂筏的特异性标志分子，采用高效薄层层析技术对脂筏进行鉴定.

Sphingomyelin Can Be Used as Specific Marker for Identifying Lipid R

Sphingolipids- and cholesterol-rich lipid microdomains in plasma membrane are termed lipid rafts.The preparation and identification of rafts are essential to studying its structure and biological function.The lipid rafts are prepared by extracting with cold non-ionic detergent and then by density gradient ultracentrifugation.GM₁, a glycosphinglipid (GSL) that highly enriched in the lipid rafts, is often used as a molecular marker for lipid rafts.The cholera toxin B subunit labelled with fluorescence or biotin, which has high affinity with GM₁, can be used as a probe for identifying lipid rafts.Howerer this procedure for lipid rafts identification is complicated，time-consuming and prone to environmental pollution.In addition,some tissue cells express little or no GM₁.Therefore the method can not be used to all the tissue cells.In the present study, to find out high specific and widely applied molecules which can be used as lipid rafts marker, the lipid component of lipid rafts from two different cell lines were analyzed.The results indicated that sphingomyelin could be used as specific marker for identifying lipid rafts by HPTLC technique.