Dataset Information

Aza-Amino Acids Disrupt ?-Sheet Secondary Structures.

ABSTRACT: C? to N substitution in aza-amino acids imposes local conformational constraints, changes in hydrogen bonding properties, and leads to adaptive chirality at the nitrogen atom. These properties can be exploited in mimicry and stabilization of peptide secondary structures and self-assembly. Here, the effect of a single aza-amino acid incorporation located in the upper ?-strand at a hydrogen-bonded (HB) site of a ?-hairpin model peptide (H-Arg-Tyr-Val-Glu-Val-d-Pro-Gly-Orn-Lys-Ile-Leu-Gln-NH₂) is reported. Specifically, analogs in which valine³ was substituted for aza-valine³ or aza-glycine³ were synthesized, and their ?-hairpin stabilities were examined using Nuclear Magnetic Resonance (NMR) spectroscopy. The azapeptide analogs were found to destabilize ?-hairpin formation compared to the parent peptide. The aza-valine³ residue was more disruptive of ?-hairpin geometry than its aza-glycine³ counterpart.

SUBMITTER: McMechen MA

PROVIDER: S-EPMC6572070 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Aza-Amino Acids Disrupt β-Sheet Secondary Structures.

McMechen Michael A MA Willis Evan L EL Gourville Preston C PC Proulx Caroline C

Molecules (Basel, Switzerland) 20190518 10

Cα to N substitution in aza-amino acids imposes local conformational constraints, changes in hydrogen bonding properties, and leads to adaptive chirality at the nitrogen atom. These properties can be exploited in mimicry and stabilization of peptide secondary structures and self-assembly. Here, the effect of a single aza-amino acid incorporation located in the upper β-strand at a hydrogen-bonded (HB) site of a β-hairpin model peptide (H-Arg-Tyr-Val-Glu-Val-d-Pro-Gly-Orn-Lys-Ile-Leu-Gln-NH<sub>2< ...[more]

PMID: 31109055

Similar Datasets

Project description:The unique physiochemical properties and multiscale organization of layered materials draw the attention of researchers across a wide range of scientific disciplines. Layered structures are commonly found in diverse biological systems where they fulfill various functions. A prominent example of layered biological materials is the organization of proteins and polypeptides into the archetypal aggregated amyloidal structures. While the organization of proteins into amyloid structures was initially associated with various degenerative disorders, it was later revealed that proteins not related to any disease could also form identical layered assemblies. Thus, it appears that the ability of peptides and proteins to produce amyloid-like aggregates represents a generic property of polyamides to assemble into higher order fibrillar structures. In the aggregated state, the peptide backbone forms ?-sheet structures which are further organized into layered arrangements. We have recently extended the identified amyloidogenic building blocks to include not only peptides or proteins, but also single amino acids and other metabolites. High resolution spectroscopy and crystallography analyses confirm the clear potential of amino acids and other metabolites to form layered amyloid-like aggregates showing biophysical and biochemical properties similar to protein amyloids. Therefore, the generic propensity of peptides and proteins backbones to assemble into layered organizations may emanate from their basic building block, the amino acid. In this Account, we aim to introduce the concept of supramolecular ?-sheet organization of single amino acids and to present an analysis of their layered-structure organization based on single crystal structures. We demonstrate that, despite the different side-chains that considerably vary in their chemical properties, all coded amino acids display a layer-like assembly stabilized by ?-amine to ?-carboxyl H-bonds, resembling supramolecular ?-sheet structures, while the side-chains determine the higher order organization of the layers. Our work presents the first analysis of the ?-sheet propensity of single amino acids in their unbound form, indicating an evolutionary predisposition. We classify the amino acids ?-sheet propensity on the basis of the interlayer separation distance in the crystal packing, which correlates well with previously reported classifications based on various criteria, such as hydrophobicity, steric bulkiness, and folding. In addition, we demonstrate that the relative direction of ?-amine to ?-carboxyl H-bonding pattern provides critical insights regarding the stabilization of parallel versus antiparallel ?-sheet structures by the various amino acids. Taken together, our analysis of amino acid crystals provides substantial information regarding protein folding and dynamics and could serve as basic rules set for the design of potential building blocks for molecular self-assembly to produce functional materials of tunable properties, an important objective of bottom-up nanotechnology.

Dataset Information

Aza-Amino Acids Disrupt ?-Sheet Secondary Structures.

Publications

Aza-Amino Acids Disrupt β-Sheet Secondary Structures.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets