With the support of the Organic and Macromolecular Chemistry Program, Professor Barbara Imperiali, of the Department of Chemistry at the Massachusetts Institute of Technology, is studying the structure, association properties, and function of "mini-protein" motifs. A 29-residue mini-motif containing a disulfide link will be rationally designed to a disulfide-free motif, and a biological strategy for "evolving" 23- and 29-residue motifs will be used to develop mini-motifs including only the 20 encoded amino acids, rather than relying on one or two D-amino acids currently used as turn stabilizing agents. New methods, including the use of fluorescent reporter groups and amino acids with solvatochromic properties, will be implemented to permit the discovery of peptide oligomers with discrete quaternary structure. Finally, Professor Imperiali will explore the possible function of these mini-motifs in the molecular recognition and sensing of small molecules such as fluorescent organic species and fluorescently labeled mono- and disaccharides.
Proteins (polypeptides), comprised of long chains of interconnected amino acids, play myriad biochemical roles. Their specific function is critically dependent on the three dimensional structure adopted by the polypeptide chain, yet the factors responsible for protein folding are still at best incompletely understood. Through the design, synthesis, and study of small polypeptides, Professor Barbara Imperiali, of the Department of Chemistry at the Massachusetts Institute of Technology, with the support of the Organic and Macromolecular Chemistry Program, is shedding light on the factors responsible for the formation of particular protein folding motifs. Her studies also explore the possibility that these "mini-motifs" could serve as scaffolds to permit the recognition and sensing of small organic molecules, including sugars, leading in the longer term to the design of peptide-based chemosensing agents.
