Preparation and investigation of unnatural polar sidechains in designed coiled-coils

ORGN 722

Maria L. Diss, Maria.Diss@colostate.edu and Alan J. Kennan, kennan@lamar.colostate.edu. Department of Chemistry, Colorado State University, Fort Collins, CO 80523
Alpha helical coiled-coils, formed by supercoiling of two or more component polypeptide strands, are ubiquitous mediators of biological structure and function. A key natural strategy for controlling specific assembly is the burial of polar side chains (particularly asparagine) at central hydrophobic core positions. Alignment of the polar side chains opposite each other, rather than hydrophobic alternatives, drives formation of the intended complex. We have begun investigating unnatural polar side chains for similar purposes. In particular, chain length arginine variants have been incorporated into coiled-coil peptides. Their synthesis involves on-resin guanidinylation using newly developed reagents. Reagent design, peptide preparation, and biophysical analysis will be discussed.