【蛋蛋与大脑】人类蛋白质图谱

The Human Protein Atlas

人类蛋白质图谱

Balls and brains

和大脑

A new chart of the body’s composition

身体构成的新图解

Nov 8th 2014 | From the print edition of The Economist

译者：jess641nx

THIS week sees the completion of a new atlas. The cartography in question, though, is biological, not terrestrial. The “Human Protein Atlas” consists of photographic maps, 13m of them, of tissue from all bodily organs. It shows which proteins are found where.

本周，刚刚完成的新图谱面世了。不过，这次研究的图谱是有关生物体的，而不是地球表面的。此“人类蛋白质图谱”由1300万张图片组成，包括了组成人体所有器官的蛋白质。

The maps were made by creating antibodies to 17,000 individual proteins, attaching staining molecules to those antibodies, and then applying the combination to thin slices

of preserved tissue to see, by what colour the tissue went, which antibodies had stuck to it.

项目是先制取17000个蛋白质的抗体，将那些抗体与荧光分子等标记物连接，再将标记抗体应用于保存的组织薄切片标本后，观察组织的颜色变化，以及附着在组织上是哪些抗体。从而绘制出了17,000个蛋白质的图像。

The result will be of great value to researchers trying to understand how tissues differ at the molecular level. Most biological functions depend on proteins, so it is the mix of proteins within a cell which defines what that cell is. The atlas will also (because 20 types of malignant tumour are included in it) help to explain how cancerous tissues differ from their healthy progenitors.

这一成果对于研究人员了解组织器官在分子水平上的差别意义重大。器官的生物学功能是蛋白质所赋予的，所以一个细胞里所含的蛋白质组合就决定了这个细胞的功能。这组图谱（因为包含了20种恶性肿瘤的蛋白质图片）还能帮助辨别癌变组织是如何由他们原本健康的亲本组织病变而来了的。

There are around 20,000 protein-coding genes in the human genome, so even though the atlas covers all parts of the anatomy, it is not yet complete. Indeed, the cellular machinery that translates the information contained in genes and uses it to construct proteins often applies tweaks to those proteins as it goes. This means there are more sorts of proteins than genes, expanding the task of mapping what is happening still further.

人类基因组中能编码产生蛋白质的基因有20000个，即便图谱包含了所有人体的组织器官构件，但还不够完整。诚然，细胞机制负责转译基因中包含的信息并使用这些信息形成蛋白质，但转译过程中产生的蛋白质会有细微调整。这就意味着蛋白质的种类会多于基因数，未来扩充蛋白质图谱的任务还有很长的路要走。

The researchers who created the atlas, led by Mathias Uhlen of the Royal Institute of Technology, in Stockholm, have nevertheless discovered that 3,500 human genes encode proteins specific to just one or two tissues. These are, presumably, crucial to what those tissues do. Many of these proteins are peculiar to the cerebral cortex—which is not surprising, as the brain is usually regarded as the body’s most complex component. But, proteinwise, it turns out that it is only the second most complex. The winning organ (a slice of which is pictured), with a third of those 3,500 genes, is the testis.

负责绘制图谱的项目是来自斯德哥尔摩的瑞典皇家工学院Mathias Uhlen 率领的研究人员进行的，他们还发现有3500个人类基因编码所产生的独特蛋白质集中在一或两个组织中。这些蛋白质可能对这些组织的功能起着决定性的作用。这些特有的蛋白质组成大脑皮层－也不奇怪，大脑通常被认为是身体中最复杂的器官。但是，按蛋白质在组织中的活跃程度来看，大脑皮层中的只能位居第二了。那个胜出的器官就是，因为它有3500个基因中的三分之一编码产生的独特蛋白质（切片如图所示）。

From the print edition: Science and technology

译者注：

（1）此处的实验方法简介：蛋白质原位杂交

步骤

1、提取纯化该蛋白（提取及纯化蛋白质的方法生化上有讲到）

2、制取该蛋白的特异性抗体 （将提取的蛋白质注入体内，使它产生免疫反应，产生特异性抗体，然后提取血清，血清中含有相应抗体）

3、将抗体与荧光分子（如GFP),辣根过氧化物酶（HRP）等标记物连接

4、标记抗体与组织切片标本孵育，抗体与细胞中相应抗原发生特异性结合，结合部位被标记物显示

5、在显微镜下观察到该肽或蛋白质的分布（抗体分子如与荧光分子连接，就在荧光显微镜下观察；如与HRP连接，则在光镜和电镜下进行观察）