Studying protein structure and function using semisynthesis.

In this review, which is more or less a transcript of my du Vigneaud Award Lecture, I cover the development and application of the protein semisynthesis technique, Expressed Protein Ligation (EPL). EPL allows the assembly of modified proteins from recombinant and synthetic peptide building blocks. The approach has been widely used since its introduction in 1998 and has allowed a number of biochemical problems to be solved through the use of CEdesigner proteins. In this article, the utility of the approach is illustrated through work in my own lab and with an emphasis on the use of EPL to study the role of protein post-translational modifications.