The Daily Bulletin Archive

Please join the Chemistry and Physics departments for the seminar "Biomimetic Structures Based on Self-Assembly and Folding," presented by Bing Gong, professor of chemistry at the University at Buffalo, on Thursday, February 20, from 12:15 to 1:30 p.m. in Science and Mathematics Complex 176.

Abstract
Creating structural and functional mimetics of biomacromolecules is of both fundamental and practical significance. Information-carrying molecules have been designed based hydrogen-bonded molecular duplexes with sequence-specific programmability and tunable stability. The well-defined structures of these unnatural oligomers, along with their DNA-like programmable specificity and high stability, have resulted in controlled intermolecular interactions and artificial nanostructures. Examples include the nucleation and stabilization of beta-sheets, the design of supramolecular block copolymers, and the templation of organic reactions.  This approach offers a set of programmable association units for directing the assembly and/or reactions of various structural units.

By controlling intramolecular non-covalent interactions, general strategies leading to folded molecular objects have been developed. Rigidifying the backbones of otherwise flexible molecular chains with localized non-covalent interactions has resulted in highly stable helical conformations in both the solid state and solution. This approach has been successfully applied to the creation of helical oligoamides, oligoureas, and oligo (phenylene ethynylenes). Unlike most known foldamers, the folding of these oligomers is encoded in their backbones and is thus independent of their sizes or the nature of their side chains. The helices contain large, tunable internal cavities. The folding of oligomer precursors was found to facilitate highly efficient macrocyclization reactions, based on which several classes of large shape-persistent macrocycles have been discovered. The crescent, helical and cyclic structures contain nanosized voids that are typically associated with the tertiary and quaternary structures of proteins. The availability of these porous molecules has provided nanosized building blocks that present both opportunities and challenges for creating the next-generation biomimetic nanostructures capable of presenting multiple introverted functional groups, forming various pores and channels and finally, developing protein-like structures and functions.