蛋白分离纯化概(An overview of protein isolation).doc

蛋白分离纯化概述（An?overview?of?protein?isolation） Isolating a protein may be compared to playing a game of golf. In golf, the player is faced with a series of problems, each unique and yet similar to problems previously encountered. In facing each problem the player must analyse the situation and decide, from experience, which club is likely to give the best result in the given circumstances. Similarly, in attempting to isolate proteins, researchers face a series of similar-yetunique problems. To solve these they must dip into their bags and select an appropriate technique. The purpose of this book is thus to fill the beginnerís “golf bag” with techniques relevant to protein isolation, hopefully to improve their game. Developing a protein isolation is also somewhat like finding a route up a mountainside. Different routes have to be explored and base-camps established at each stage. Occasionally it will be necessary to return to the base of the mountain for further supplies, and haul these up to the established camps, before the next stage can be attacked. A successful climb is always rewarding and if an efficient route is established, it may become a pass, opening the way to further discoveries. 1.1 Why do it? This book is about the methods that biochemists use to isolate proteins, and so it may be asked, “why isolate proteins?” Looked at in one way, living organisms may be regarded as machines with features in common with the entities that we commonly think of as “machines”. A typical machine is made of a number of parts which interact, transduce energy, and bring about some desired effect. Mechanical machines have moving parts, while electronic machines move electrons. “Engines” convert energy to mechanical motion. Internal combustion engines, for example, convert chemical energy to mechanical motion. Similarly, living organisms such as the human body are complex machines made up of many interacting systems. Proteins constitute the majority of the working parts of these