ABSTRACT
Proteins and enzymes are the final products of gene expression. Although deoxyribonucleic acid (DNA) stores the genetic information, it is the proteins that determine the shape and structure of a cell, a tissue, an organ, and the intact organism. Enzymes, which are usually proteins in nature, control the expression of genes and the development of an organism. Overall, proteins constitute half of the dry weight of the cell. In recent years, proteins and enzymes have become one of the core parts of molecular biology studies. This “hot field” primarily comes from the concept of “reverse genetics.” A number of molecular biology studies start from specific protein(s) that determine the particular phenotype of an organism, and go back to clone, identify, and characterize the specific gene(s) expressing the protein(s) of interest. In addition, proteins/enzymes are involved in broad molecular biology studies such as the interaction between the cis-element and trans-factor, DNA/protein interaction in gel retardation and footprinting, screening of cDNA libraries as probes, immunoblotting or precipitation, and in vitro translation.1-7
In the study of proteins and enzymes, extraction and purification of these macromolecules are fundamentally important.1,8,9 The present chapter describes the procedures for extraction and purification in detail.
