Synthesis and Assembly of Recombinant Collagen

Collagen represents the major structural protein of the extracellular matrix. The desired mechanical and biological performances of collagen that have led to its broad applications as a building block in a great deal of fields, such as tissue engineering, drug delivery, and nanodevices. The most direct way to obtain collagen is to separate and extract it from biological tissues, but these top-down methods are usually cumbersome, and the structure of collagen is usually destroyed during the preparation process. Moreover, there is currently no effective method to separate some scarce collagens (such as collagen from human beings). Alternatively, bottom-up assembly methods have been developed to obtain collagen assembly or their analogs. The collagen used in this type of method is usually obtained by genetic recombination. A distinct advantage of gene recombination is that the sequence structure of collagen can be directly customized, so its assembly mode can be regulated at the primary structure level, and then a collagen assembly with a predesigned configuration can be achieved. Additionally, insights into the assembly behavior of these specific structures provide a rational approach to understand the pathogenic mechanisms of collagen-associated diseases, such as diabetes. In this chapter, Type I collagen is used as an example to introduce the key methods and procedures of collagen recombination, and on this basis, we will introduce in detail the experimental protocols for further assembly of these recombinant proteins to specific structures, such as fibril.