Abstract With increasing ring-crossing number ( c ), knot theory predicts an exponential increase in the of topologically different links these interlocking structures, even for structures with same ring n ) and . Here, we report selective construction two topologies 12-crossing peptide [4]catenanes = 4, 12) from metal ions pyridine-appended tripeptide ligands. Two 100 possible this structure are selectively created related ligands which only sequence is changed: one catenane has a T 2...

Short peptide helices have attracted attention as suitable building blocks for soft functional materials, but they are rarely seen in crystalline materials. A new artificial nanoassembly of short the state is presented which arranged three-dimensionally by metal coordination. The folding and assembly processes a ligand containing Gly-Pro-Pro sequence were induced silver(I) coordination aqueous alcohol, gave rise to single crystal composed polyproline II helices. Crystallographic studies...

Abstract A topologically complex peptide [4]catenane with the crossing number of 12 was synthesized by a folding and assembly strategy wherein metal‐directed self‐assembly short fragment occur simultaneously. The latent Ω‐looped conformation Pro‐Gly‐Pro sequence found only when pyridines at C‐ N‐termini coordinatively bind metal ions (Ag I or Au ). Crystallographic studies revealed that motifs formed four M 3 L macrocycles were intermolecularly entwined to generate an unprecedented topology.

Hydrogen bond (H-bond) formation in water has been a challenging task because molecules are constant competitors. In biological systems, however, stable H-bonds formed by shielding the H-bonding sites from competing within hydrophobic pockets. Inspired nature's elaborated way, we found that even mononucleotides (G and C) can form minimal G·C Watson−Crick pair simply providing synthetic cavity efficiently shields sites. The structure was elucidated NMR study firmly characterized...

Mutual induced fit is an important phenomenon in biological molecular recognition, but it still rare artificial systems. Here we report host–guest system which a flexible calix[4]arene enclathrated dynamic self-assembled host and both molecules mutually adopt specific three-dimensional structures. NMR data revealed the conformational changes, crystallographic studies clearly established precise structures at each stage.

Abstract Cavity creation is a key to the origin of biological functions. Small cavities such as enzyme pockets are created simply through liner peptide folding. Nature can create much larger by threading and entangling large rings, learned from gigantic virus capsids, where not only chemical structures but topology threaded rings must be controlled. Although interlocked molecules topic current interest, they have for decades been explored merely elements molecular machines, or synthetic...

Self-assembled coordination cages can be employed as a molecular press, where the bowl-shaped guest corannulene (C20H10) is significantly flattened upon inclusion within hydrophobic cavity. This demonstrated by pairwise of with naphthalene diimide well dimer bromocorannulene inside box-like host. The compressed structures are unambiguously revealed single-crystal X-ray analysis.

Abstract Guest‐induced M 18 L 6 –M 24 8 capsule–capsule conversion is reported. Both capsules are composed of Pd II ethylenediamine units (M) and 1,3,5‐tris(3,5‐pyrimidyl)pyrimidine (L), form trigonal bipyramidal (M ) octahedral closed‐shell structures with huge hydrophobic inner spaces. The bipyramid converted to the octahedron through encapsulation large aromatic guests, latter capsule possessing a cavity volume three times larger than former. Despite dynamic properties host, encapsulated...

Despite the frequent occurrence of knotted frameworks in protein structures, latent potential peptide strands to form entangled structures is rarely discussed chemistry. Here we report construction highly molecular topologies from Ag(I) ions and tripeptide ligands. The efficient entanglement metal–peptide wide scope for design amino acid side chains these ligands enabled 91 torus knots 1012 links. Moreover, steric control chain induced ring opening twisting framework, which resulted an...

There is broad interest in molecular encapsulation as such systems can be utilized to stabilize guests, facilitate reactions inside a cavity, or give rise energy-transfer processes confined space. Detailed understanding of events required functional encapsulation. In this contribution, it demonstrated that Ir and Rh-Cp-type metal complexes encapsulated self-assembled M

Abstract Construction of entangled nanostructures from molecular rings or strands has long attracted chemists, yet synthetic approaches for highly remain unexplored to date. Here, we introduce our recent achievements in construction such by utilization metal–peptide strands. Our folding-and-assembly strategy, that is based on a cooperative processes peptide self-folding and metal-induced self-assembly, afforded unprecedented topological through threading multiple rings. Starting the initial...

Folding in the confine: Short fragments of tri- to hexapeptides have been encapsulated by a synthetic host water and folded into their latent helical structures (see crystal structure). Crystallographic analysis complexes clearly reveals mixed conformation 310 α helices, thereby illustrating inherent propensity very short peptide fragments.

Artificial mimicry of α-helices offers a basis for development protein–protein interaction antagonists. Here we report new type unnatural peptidic backbone, containing α-, β-, and γ-amino acid residues in an αγααβα repeat pattern, this purpose. This hexad has the same number backbone atoms as heptad α residues. Two-dimensional NMR data clearly establish formation α-helix-like conformation aqueous solution. The helix formed by our 12-mer α/β/γ-peptide is considerably more stable than α-helix...

Abstract Short peptide helices have attracted attention as suitable building blocks for soft functional materials, but they are rarely seen in crystalline materials. A new artificial nanoassembly of short the state is presented which arranged three‐dimensionally by metal coordination. The folding and assembly processes a ligand containing Gly‐Pro‐Pro sequence were induced silver(I) coordination aqueous alcohol, gave rise to single crystal composed polyproline II helices. Crystallographic...

The de novo construction of repeat proteins has received much attention from biologists and chemists, yet that a β-barrel structure, one the most well-known classes, not been accomplished to date. Here, we report first chemical tertiary structure with pore through combination peptide folding metal-directed self-assembly. Coordination zinc salts an eight-residue fragment bearing β-strand- loop-forming sequences resulted in which six-stranded cylindrical antiparallel β-sheets formed...

Porous metal complexes enable single-crystal X-ray crystallographic observation of included guests or reaction intermediates through simple soaking with the guests/substrates. Previous studies on this technique have often encountered difficulties in chiral structures because host frameworks had no chirality. We synthesized a new metal-peptide porous complex folding-and-assembly strategy and utilized pore for trapping guests. Chiral alcohols ketones were successfully within pore....

The chirality of helical polypeptides is correlated to that their constituent amino acid residues. For with non-natural backbones, however, such correlations are less clear. Here, circular double helices torus knot/link topologies were assembled from metal-peptide chains composed Ag(I) ions and ditopic tripeptides Gly-Gly-Ala Gly-Ala-Gly sequences. We found the structures determined by l-Ala's dihedral angles. A tubular dimeric structure an M21L14 composition was further achieved via...

Matching matters when building supramolecular n/p-heterojunction photosystems on solid supports that excel with efficient photocurrent generation, important critical thickness, smooth surfaces, and flawless responsiveness to functional probes for the existence of operational intra- interlayer recognition motifs. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by...

The steric zipper is a common hydrophobic packing structure of peptide side chains that forms between two adjacent β-sheet layers in amyloid and related fibrils. Although previous studies have revealed fragments derived from native protein sequences exhibit structures, their de novo designs rarely been studied. Herein, structures were artificially constructed the crystalline state by metal-induced folding assembly tetrapeptide Boc-3pa-X1-3pa-X2-OMe (3pa: β-(3-pyridyl)-l-alanine; X1 X2: amino...

Short peptides were induced into alpha-helix conformations in water through enclathration to an artificial hydrophobic cavity. Peptides with two aromatic residues showed high affinity for the host, and these intermolecular aromatic-aromatic interactions specifically drove helical folding of short peptides.

Abstract Concerted folding and assembly processes are necessary for protein self‐assembly, yet such a concerted strategy has rarely been attempted by synthetic chemists. In this work, we have created new porous peptide structure through coordination‐driven folding‐and‐assembly strategy. A framework with 1.5 nm‐sized pores P II helical scaffold was successfully obtained complexation of AgNTf 2 tripeptide ligands containing the Gly‐Pro‐Pro sequence. The were modified in various ways retention...

Abstract Guest‐induced M 18 L 6 –M 24 8 capsule–capsule conversion is reported. Both capsules are composed of Pd II ethylenediamine units (M) and 1,3,5‐tris(3,5‐pyrimidyl)pyrimidine (L), form trigonal bipyramidal (M ) octahedral closed‐shell structures with huge hydrophobic inner spaces. The bipyramid converted to the octahedron through encapsulation large aromatic guests, latter capsule possessing a cavity volume three times larger than former. Despite dynamic properties host, encapsulated...