摘要
词法上， caveolae 和类脂化合物椽子是二不同的膜结构。他们经常被报导分享类似的类脂化合物和蛋白质作文，并且被认为是膜类脂化合物 microdomains 的二种子类型。由修改蔗糖密度坡度筹款 centrifugation，它被用来孤立类脂化合物 microdomains，我们能把 caveolae 和 noncaveolar 类脂化合物 microdomains 分开成二不同部分。caveolar 膜是 100-nm 直径的膜泡，与 caveolin-1 和 flotillin-1 充实。noncaveolar 类脂化合物 microdomains 是非结晶的膜并且很可能异构的类脂化合物椽子的结合。他们 caveolin-1 被弄空，更多比 caveolae 与胆固醇和 sphingolipids 被充实。许多膜蛋白质例如像胰岛素的生长 factor-1 受体(膜受体) ， aquaporin-1 (膜 transporter )(抛锚 glycosylphosphatidylinositol 的膜蛋白质和膜 glycoprotein ) ， Thy-1 和 N-cadherin，明确地与 noncaveolar 类脂化合物 microdomains，然而并非与 caveolae 被联系。这些结果显示 caveolae 的类脂化合物和蛋白质作文 noncaveolar 类脂化合物 microdomains 不同于那些。在他们的蛋白质作文的差别暗示这二膜 microdomains 可以有不同细胞的功能。
Morphologically, caveolae and lipid rafts are two different membrane structures. They are often reported to share similar lipid and protein compositions, and are considered to be two subtypes of membrane lipid microdomains. By modifying sucrose density gradient flotation centrifugation, which is used to isolate lipid microdomains, we were able to separate caveolae and noncaveolar lipid microdomains into two distinct fractions. The caveolar membranes are membrane vesicles of 100-nm diameter, enriched with caveolin-1 and flotillin-1. The noncaveolar lipid microdomains are amorphous membranes and most likely the coalescence of heterogeneous lipid rafts. They are depleted of caveo- lin-1 and are more enriched with cholesterol and sphingolipids than the caveolae. Many membrane proteins, such as insulin-like growth factor-1 receptor （membrane receptor）, aquaporin-1 （membrane transporter）, Thy-1 and N- cadherin （glycosylphosphatidylinositol-anchored membrane protein and membrane glycoprotein）, are specifically as- sociated with noncaveolar lipid microdomains, but not with caveolae. These results indicate that the lipid and protein compositions of caveolae differ from those of noncaveolar lipid microdomains. The difference in their protein compo- sitions implies that these two membrane microdomains may have different cellular functions.
