title: Sequence-specific polypeptoids: a diverse family of heteropolymers with stable secondary structure.
abstract: We have synthesized and characterized a family of structured oligo-N-substituted-glycines (peptoids) up to 36 residues in length by using an efficient solid-phase protocol to incorporate chemically diverse side chains in a sequence-specific fashion. We investigated polypeptoids containing side chains with a chiral center adjacent to the main chain nitrogen. Some of these sequences have stable secondary structure, despite the achirality of the polymer backbone and its lack of hydrogen bond donors. In both aqueous and organic solvents, peptoid oligomers as short as five residues give rise to CD spectra that strongly resemble those of peptide alpha-helices. Differential scanning calorimetry and CD measurements show that polypeptoid secondary structure is highly stable and that unfolding is reversible and cooperative. Thermodynamic parameters obtained for unfolding are similar to those obtained for the alpha-helix to coil transitions of peptides. This class of biomimetic polymers may enable the design of self-assembling macromolecules with novel structures and functions.
authors.affiliation: Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143.
authors.forename: K
authors.initials: K
authors.lastname: Kirshenbaum
authors.forename: A E
authors.initials: AE
authors.lastname: Barron
authors.forename: R A
authors.initials: RA
authors.lastname: Goldsmith
authors.forename: P
authors.initials: P
authors.lastname: Armand
authors.forename: E K
authors.initials: EK
authors.lastname: Bradley
authors.forename: K T
authors.initials: KT
authors.lastname: Truong
authors.forename: K A
authors.initials: KA
authors.lastname: Dill
authors.forename: F E
authors.initials: FE
authors.lastname: Cohen
authors.forename: R N
authors.initials: RN
authors.lastname: Zuckermann
mesh_terms: D002942:Circular Dichroism; D003198:Computer Simulation; D005998:Glycine / Q000031:analogs & derivatives*; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D034444:Peptoids; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D010455:Peptides; D034444:Peptoids; C011080:polyglycine; D005998:Glycine