Protein Expression
A protein expression system refers to a system consisting of a host, foreign genes, vectors and auxiliary components. Through this system, the purpose of expressing foreign genes in the host can be achieved. This system usually consists of several parts: 1. Host. Organisms that express proteins. 2, the carrier. The type of vector matches the host. 3. Auxiliary ingredients. Protein expression systems are divided into E. coli expression systems, yeast expression systems, insect expression systems, mammalian expression systems and plant expression systems. Various expression systems have their own advantages and disadvantages. E. coli expression system has a high yield capacity in a short time and low cost. But the target protein is often expressed in the form of inclusion bodies therefore product purification is difficult. The post-translational modifications of the prokaryotic expression is imperfect, and the biological activity of the expression product is low; Yeast and insect cell expression systems have high protein expression levels and low cost, but the post-translational processing modification systems are not exactly the same as those of mammals; The protein produced by mammalian expression system is closer to the natural state, but the expression amount is low and the operation is cumbersome.
