Harnessing a bis-electrophilic boronic acid lynchpin for azaborolo thiazolidine (ABT) grafting in cyclic peptides.

Chemical modifications of native peptides have significantly advanced modern drug discovery in recent decades. On this front, the installation of multitasking molecular grafts onto macrocyclic peptides offers numerous opportunities in biomedical applications. Here, we showcase a new class of borono-cyclic peptides featuring an azaborolo thiazolidine (ABT) graft, which can be readily assembled utilizing a bis-electrophilic boronic acid lynchpin while harnessing the inherent reactivity difference (>10 M s) between the N-terminal cysteine and backbone cysteine for rapid and highly regioselective macrocyclization (∼1 h) under physiological conditions.

Chemically fueled dynamic switching between assembly-encoded emissions.

Self-assembly provides access to non-covalently synthesized supramolecular materials with distinct properties from a single building block. However, dynamic switching between functional states still remains challenging, but holds enormous potential in material chemistry to design smart materials. Herein, we demonstrate a chemical fuel-mediated strategy to dynamically switch between two distinctly emissive aggregates, originating from the self-assembly of a naphthalimide-appended peptide building block.

Disulphide Cross-Linked Ultrashort Peptide Hydrogelator for Water Remediation.

A single amino acid in a peptide sequence can play an important role to tune the self-assembly and hydrogelation behaviour. Here, a C-terminal cysteine-containing ultrashort peptide hydrogelator forms hydrogel through non-covalent and covalent interactions. Interestingly, the hydrogel is insoluble in water and buffer solutions at different pH values (1-13) and is thixotropic and injectable.

Rapid and Highly Productive Assembly of a Disulfide Bond in Solid-Phase Peptide Macrocyclization.

Here we report a highly efficient disulfide-driven peptide macrocyclization in 15 min on a solid support using persulfate as a crucial additive in iodine-mediated oxidative cyclization. The method eliminates the side products of classical iodine-mediated peptide cyclization. It is operationally simple and convenient for cyclizing small to lengthier peptides embodying popular cysteine building blocks in a single step.

Cumulative Effect of pH and Redox Triggers on Highly Adaptive Transient Coacervates.

An intricate synergism between multiple biochemical processes and physical conditions determines the formation and function of various biological self-assemblies. Thus, a complex set of variables dictate the far-from-equilibrium nature of these biological assemblies. Mimicking such systems synthetically is a challenging task.

Development of a hydrolase mimicking peptide amphiphile and its immobilization on silica surface for stereoselective and enhanced catalysis.

Biocatalysis is an important area of modern research and is extensively explored by various industries to attain greener methods in various applications. Supramolecular interactions of short peptides have been under the scanner for developing artificial smart materials inspired from natural systems. Peptide-based artificial enzymes have been proved to show various enzyme-like activities.

Bi-directional feedback controlled transience in Cucurbituril based tandem nanozyme.

Life is fueled by multi-enzymatic tandem processes that display unmatched catalytic efficiencies owing to certain features of the biological reactors such as compartmentalization, nano-confinement, and out-of-equilibrium dynamics. With an attempt to match such natural catalytic systems, herein, we present a chemoenzymatic pH clock mediated transient assembly of a vesicular nanozyme. Distinct confinement of two catalytically discrete units, Histidine groups on the periphery and hemin in the lipid bilayer, results in an efficient hydrolase-peroxidase tandem catalysis in a temporally controlled fashion.

Light-triggered syneresis of a water insoluble peptide-hydrogel effectively removes small molecule waste contaminants.

A short peptide based hydrogel exhibits aqueous insolubility, thixotropy and efficient light induced syneresis. Upon irradiation with UV light, the hydrogel shrinks and expells ∼50% of the solvent. Syneresis is caused by light-triggered trans-cis isomerisation of an azobenzene moiety in the peptide derivative.

Freeze the dynamicity: charge transfer complexation assisted control over the reaction pathway.

Charge transfer (CT) complexes between electron donor and acceptor molecules provide unique alternate D-A arrangements. However, these arrangements cannot be fully translated into chemo-selective organic transformations as the dynamicity of CT complexes in solution results in the co-existence of D-A assemblies and free monomers during the reaction time-scale. A conceptually new strategy to exploit CT complexes toward chemo-selective products by means of seizing the dynamicity of CT complexes is reported here.

Unusual confinement properties of a water insoluble small peptide hydrogel.

Unlike polymeric hydrogels, in the case of supramolecular hydrogels, the cross-linked network formation is governed by non-covalent forces. Hence, in these cases, the gelator molecules inside the network retain their characteristic physicochemical properties as no covalent modification is involved. Supramolecular hydrogels thus get dissolved easily in aqueous medium as the dissolution leads to a gain in entropy.

Unorthodox Combination of Cation-π and Charge-Transfer Interactions within a Donor-Acceptor Pair.

Cation-π and charge-transfer (CT) interactions are ubiquitous in nature and involved in several biological processes. Although the origin of both the interactions in isolated pairs has extensively been studied, CT interactions are more prominent in supramolecular chemistry. Involvement of cation-π interactions in the preparation of advanced functional soft materials is uncommon.