Preparation of pure proteins in a sufficient amount and desired quality is a crucial step in structure-function studies. The main problems encountered on the way from the gene expression to protein structure determination are related to protein solubility, homogeneity and crystallizability.
A variety of methods have been developed for protein production, purification, etc., however, all steps and conditions have to be optimized with respect to the properties of each individual protein. Thus, the protein itself can be considered as one of the parameters and can also be optimized. Possible approaches and strategies for modifying proteins, e.g. design of single amino acid mutations or fusion proteins, using the methods of bioinformatics and molecular biology will be discussed.