MEMBRANE STRUCTURE - SOME GENERAL PRINCIPLES
MEMBRANE STRUCTURE - SOME GENERAL PRINCIPLES
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DOI：
10.1126/science.181.4100.622
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发表时间：
1973-01-01
期刊：
影响因子：
56.9
通讯作者：
BRETSCHER, MS
中科院分区：
文献类型：
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作者：
BRETSCHER, MS
本文还讨论了红细胞膜上脂质和某些蛋白质的排列。由此得出的结论在这里被列为一套高等生物膜结构的一般准则：其中一些规则可能是错误的。但在这个阶段，以这种方式使我们的思想变得尖锐，从而将注意力集中在各种具体点上似乎是有用的。1）膜的基础是脂质双层，其中（i）胆碱磷脂和糖脂在外半部分，（ii）氨基（可能还有一些胆碱）磷脂在胞质半部分。实际上不存在跨双层的脂质交换（除非酶催化）。2）一些蛋白质延伸跨双层。在这种情况下，它们通常在远离细胞质的表面上具有碳水化合物。这种碳水化合物可以阻止蛋白质从膜扩散到细胞质中;它对蛋白质起着锁定作用。3）就像脂质不会翻转一样，蛋白质不会穿过膜旋转。脂质和蛋白质在双分子层平面内的横向运动或旋转是可以预期的。4）大多数膜蛋白与膜的内部、细胞质、表面相关联。蛋白质通常并不只与脂质双层的外半部分结合。5）膜蛋白是一类特殊的细胞质蛋白，而不是分泌蛋白。
The arrangement of lipids and some proteins in the erythrocyte membrane has been discussed. The conclusions from this are listed here as a set of general guidelines for the structure of membranes of higher organisms: some of these rules may be wrong. But at this stage it seems useful to sharpen our thoughts in this way and thereby focus attention on various specific points.1) The basis of a membrane is a lipid bilayer with (i) choline phospholipids and glycolipids in the external half and (ii) amino (and possibly some choline) phospholipids in the cytoplasmic half. There is effectively no lipid exchange across the bilayer (unless enzymatically catalyzed).2) Some proteins extend across the bilayer. Where this is so, they will in general have carbohydrate on their surface remote from the cytoplasm. This carbohydrate may prevent the protein diffusing out of the membrane into the cytoplasm; it acts as a lock on the protein.3) Just as lipids do not flip-flop, proteins do not rotate across the membrane. Lateral motion or rotation of lipids and proteins in the plane of the bilayer may be expected.4) Most membrane protein is associated with the inner, cytoplasmic, surface of the membrane. Proteins are not usually associated exclusively with the outer half of the lipid bilayer.5) Membrane proteins are a special class of cytoplasmic proteins, not of secreted proteins.