细胞4,细胞膜与细胞表面.ppt

In many cases, one can use proteases to cut the loops of the polypeptide chain that link the transmembrane a helices one either side of the bilayer and the helices stay together and function normally. In some cases, one can even express engineered genes encoding separate pieces of a multipass protein in living cells, and one finds that the separate pieces assemble properly to form a functional transmembrane protein, emphasizing the exquisite specificity with which transmembrane a helices can interact. In this example functional Na+-K+ ATPase molecules are purified and incorporated into phospholipid vesicles. 紫细菌 脑苷脂类 神经节苷脂 　一类主要的不溶于水的蛋白质，通常都含有呈现相同二级结构的多肽链, 许多纤维蛋白结合紧密，并为单个细胞或整个生物体提供机械强度，起着保护或结构上的作用。 水通道蛋白 原肌球蛋白 阴离子通道蛋白。携带氧和二氧化碳的，起物质交换的作用 血型糖蛋白又称涎糖蛋白(sialoglycoprotein),因它富含唾液酸。血型糖蛋白是第一个被测定氨基酸序列的蛋白质,有几种类? 型，包括A、B、C、D。血型糖蛋白B、C、D在红细胞膜中浓度较低。血型糖蛋白A是一种单次? 跨膜糖蛋白,? 由131个氨基酸组成,?其亲水的氨基端露在膜的外侧,? 结合16个低聚糖侧链。血型糖蛋白的基本功能可能是在它的唾液酸中含有大量负电荷,防止? 了红细胞在循环过程中经过狭小血管时相互聚集沉积在血管中。 卵磷脂 鞘磷脂 950509 4008950509 The lateral diffusion of membrane lipids can demonstrated experimentally by a technique called Fluorescence Recovery After Photobleaching (FRAP). 膜蛋白流动性的研究技术： Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 由于抗体有两个抗原结合位点，可交联相邻的膜蛋白，随着时间的延长，已均匀分布在细胞表面的标记荧光重新排布，聚集在细胞表面的某些部位，此为成斑现象，如聚集在细胞的一端，即为成帽现象。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 由于某些膜蛋白与膜下细胞骨架相结合，或者由于细胞中某些特殊结构的限定, 以及膜蛋白与膜脂分子的相互作用，使某些膜蛋白的流动性受限。 The proteins can self-assemble into large aggregates (A); they can be tethered by interactions with assemblies of macromolecules outside (B) or inside (C) the cell; or they can interact with proteins on the s