Summary:
A team from Berkely Lab generates a protein-like function from a synthetic polymer: two helical peptoids with functional groups at the end, linked together using an unstructured segment. The two-helix bundle can fold in half and bind a zinc ion. Perhaps anitial step toward developing nanostructures that combine the precision of proteins with the ruggedness of non-natural materials. Such foldable polymer bundles could lead to highly accurate sensors capable of operating in harsh environments, or disease-targeting pharmaceuticals that last much longer than today's therapies. (Published: 22/07/08)
Notes:
- proteins
- unmatched molecular recognition and catalysis capabilities
- have the ability to selectively bind with one—and only one—type of molecule
- also initiate incredibly precise chemical transformations
- e.g. cutting a DNA strand in just the right place
- hitch: lack ruggedness and stability
- limited to narrow temperature and acidity ranges
- require a watery solution
- degrade over time
- drawbacks limit their utility
- proteins to target pathologies at the molecular scale degrade over time, curbing their effectiveness
- protein-based sensor would be unsurpassed at sniffing out harmful contaminants, but it wouldn't be able to operate in hot, cold, or dry conditions
- Ron Zuckermann
- Facility Director of the Biological Nanostructures Facility in Berkeley Lab's Molecular Foundry
- goal: take proteins' catalysis and molecular-recognition capabilities, and add them to a material that is more rugged and less prone to degradation
- peptoids
- proteins are precisely folded linear polymer chains of amino acids
- made similar polymer chain by linking together non-natural amino acids
- peptoid: synthetic structures that mimic peptides
- use peptoids to build synthetic structures that behave like proteins
- binding zinc
- zinc: drives many fundamental biological processes
- developed helical peptoids with zinc-binding residues positioned at both ends
- also added fluorescent tags at both end: allowed measuring when the bundles fold in half, trapping zinc in place
