Chapter 6 - Molecular Organization of Peptides and Their Function

Abstract

This chapter describes the molecular organization of peptides and their function. The chapter describes the formation of functional assemblies of α-helical peptide molecules under the strict control of individual molecular conformation and molecular organization, which has been done mainly by the author's group. A number of investigations have been carried out on molecular assemblies of helical peptides. Under high pressure at the air-water interface the helical peptides are stacked over the monolayer to build up a bilayer, or the helical conformation is transformed into β-sheet structure, which is stabilized by hydrogen bonds between neighboring peptide molecules. On the other hand, the peptides containing Aib residues in the sequence adopt a stable or-helical conformation in molecular assemblies—even under high pressure—because of the steric condition around the two or-methyl groups of the Aib residue. Furthermore, Aib-containing peptides tend to crystallize with a quality high enough for X-ray analysis, suggesting a good molecular packing property. Therefore, Aib-containing peptides will form 2D crystals at the air-water interface without transforming the conformation or disruption to the multiplayer.