Hierarchical self-assembly of a biomimetic diblock copolypeptoid into homochiral superhelices.
The aqueous self-assembly of a sequence-specific bioinspired peptoid diblock copolymer into monodisperse superhelices is demonstrated to be the result of a hierarchical process, strongly dependent on the charging level of the molecule. The partially charged amphiphilic diblock copolypeptoid 30-mer, [N-(2-phenethyl)glycine](15)-[N-(2-carboxyethyl)glycine](15), forms superhelices in high yields, with diameters of 624 ± 69 nm and lengths ranging from 2 to 20 μm. Chemical analogs coupled with X-ray scattering and crystallography of a model compound have been used to develop a hierarchical model of self-assembly. Lamellar stacks roll up to form a supramolecular double helical structure with the internal ordering of the stacks being mediated by crystalline aromatic side chain-side chain interactions within the hydrophobic block. The role of electrostatic and hydrogen bonding interactions in the hydrophilic block is also investigated and found to be important in the self-assembly process.
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, USA.
Hannah K
HK
Murnen
Adrianne M
AM
Rosales
Jonathan N
JN
Jaworski
Rachel A
RA
Segalman
Ronald N
RN
Zuckermann
D040761:Biomimetic Materials / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008956:Models, Chemical; D034444:Peptoids / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012542:Scattering, Radiation; D055672:Static Electricity
D034444:Peptoids