Artificial Metal–Peptide Assemblies: Bioinspired Assembly of Peptides and Metals through Space and across Length Scales

Abstract

The exploration of chiral crystalline porous materials, such as metal–organic complexes (MOCs) or metal–organic frameworks (MOFs), has been one of the most exciting recent developments in materials science owing to their widespread applications in enantiospecific processes. However, achieving specific tight-affinity binding and remarkable enantioselectivity toward important biomolecules is still challenging. Perhaps most critically, the lack of adaptability, compatibility, and processability in these materials severely impedes practical applications in chemical engineering and biological technology. In this Perspective, artificial metal–peptide assemblies (MPAs), which are achieved by the assembly of peptides and metals with nanometer-sized cavities or pores, is a new development that could address the current bottlenecks of chiral porous materials. Bioinspired assembly of pore-forming MPAs is not foreign to biological systems and has granted scientists an unprecedented level of control over the chiral recognition sites, conformational flexibility, cavity sizes, and hydrophilic segments through ultrafine-tuning of peptide-derived linkers. We will specifically discuss exemplary MPAs including structurally well-defined metal–peptide complexes and highly crystalline metal–peptide frameworks. With insights from these structures, the peptide assembly and folding by the closer cooperation of metal coordination and noncovalent interactions can create adaptable protein-like nanocavities undergoing a myriad of conformational variations that is reminiscent of enzymatic pockets. We also consider challenges to advancing the field, where the deployment of side-chain groups and manipulation of amino acid sequences are more likely to access the programmable, genetically encodable peptide-mediated porous materials, thus contributing to the enhanced enantioselective recognition as well as enabling key biochemical processes in next-generation versatile biomimetic materials.

Exploring the similarity of single-layer covalent organic frameworks using electronic structure calculations

“…1(d) shows extensions and variations of p-systems, which have been chosen to specically gauge the effect of reduced aromaticity on the electronic properties. In this category, functionalized pyrene with methyl group linker 51,52 (meth-QL-Ph-Ph in Fig. 1(d)) has been included in order to understand the effect of side chains in the linker for the electronic band structure.…”

Assembly of π-Stacking Helical Peptides into a Porous and Multivariable Proteomimetic Framework

“…More importantly, optimization of the pores, which requires having mutable sites, remains underdeveloped likely due to the limitations associated with both short peptides and metal-coordination bonds. The few amino acid positions not involved in connecting the metal nodes (usually only one, thus far) poorly tolerate functionally important polar side-chains (e.g., those bearing a carboxylic acid, N-donors, or S-donors) that potentially interfere with metal binding, while variations to nonpolar residues tend to drastically restructure the topology of the framework since they are involved in key packing interactions. ,,,− …”

Supramolecular Hybrids from Cyanometallate Complexes and Diblock Copolypeptide Amphiphiles in Water

“…The combination of various transition metals with peptides can also affect the three-dimensional accumulation of metal ions. For example, the formation of polyhedral peptides using oligopeptide chains and metal ions and the use of these materials as artificial enzymes due to them having large internal cavities was recently reported [ 52 , 53 , 54 ]. These previous studies suggest that amphiphilic polypeptides can provide a suitable “bottom-up” approach to nanofabrication because the nanostructures of these polymers can be controlled by changing the ratio of hydrophobic to hydrophilic groups.…”