Oil in water emulsions are an important class of soft material that are used in the food, cosmetic, and biomedical industries. These materials are formed through the use of emulsifiers that are able to stabilize oil droplets in water. Historically emulsifiers have been developed from lipids or from large biomolecules such as proteins. However, the ability to use short peptides, which have favorable degradability and toxicity profiles is seen as an attractive alternative. In this work, we demonstrate that it is possible to design emulsifiers from short (tetra) peptides that have tunability (i.e., the surface activity of the emulsion can be tuned according to the peptide primary sequence). This design process is achieved by applying coarse grain molecular dynamics simulation to consecutively reduce the molecular search space from the 83,521 candidates initially considered in the screen to four top ranking candidates that were then studied experimentally. The results of the experimental study correspond well to the predicted results from the computational screening verifying the potential of this screening methodology to be applied to a range of different molecular systems.

In this work, we describe the development of a computational screening approach for tripeptide-dipeptide co-assembly. Studies are carried out both in water and in oil-water mixtures, to evaluate possible candidates that give rise to hydrogels or more stable emulsions, respectively, through nanofibre formation. The results give rise to design rules for the identification of promising systems for numerous types of soft materials. The possibility of achieving innovative functional materials through the co-assembly of tripeptides and dipeptides is studied. In particular, coarse-grained simulations allowed for the extraction of some promising dipeptides that, together with H-aspartyl-phenylalanyl-phenylalanine-OH (DFF), are able to act as hydrogelators or emulsifiers with superior characteristics relative to DFF on its own. [GRAPHICS] .

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Melanins are a family of heterogeneous polymeric pigments that provide ultraviolet (UV) light protection, structural support, coloration, and free radical scavenging. Formed by oxidative oligomerization of catecholic small molecules, the physical properties of melanins are influenced by covalent and noncovalent disorder. We report the use of tyrosine-containing tripeptides as tunable precursors for polymeric pigments. In these structures, phenols are presented in a (supra-)molecular context dictated by the positions of the amino acids in the peptide sequence. Oxidative polymerization can be tuned in a sequence-dependent manner, resulting in peptide sequence-encoded properties such as UV absorbance, morphology, coloration, and electrochemical properties over a considerable range. Short peptides have low barriers to application and can be easily scaled, suggesting near-term applications in cosmetics and biomedicine.

Peptide co-assembly is of interest for the development of functional supramolecular biomaterials. Herein, computational simulations were combined with experimental validation to aid the design and understanding of cooperative co-assembly of a structure-forming tripeptide (FFD) and a functional copper-binding tripeptide (GHK) leading to hydrogel formation in response to complexation with copper ions.

A series of tripeptides is shown to form emulsions with sequence tunable properties. Using a combination of simulations and experiments, it is shown that two types of oil-in-water emulsions may be produced, either forming stable interfacial nanofiber networks with remarkable stability, or more conventional surfactant-like monolayers.

Advanced MaterialsVolume 28, Issue 7 p. 1329-1329 Cover PictureFree Access Emulsifiers: Tripeptide Emulsifiers (Adv. Mater. 7/2016) Gary G. Scott, Gary G. Scott WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UKSearch for more papers by this authorPaul J. McKnight, Paul J. McKnight Macphie of Glenbervie, Stonehaven, AB39 3YG ScotlandSearch for more papers by this authorTell Tuttle, Corresponding Author Tell Tuttle WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UKSearch for more papers by this authorRein V. Ulijn, Corresponding Author Rein V. Ulijn WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UK Advanced Science Research Center (ASRC) and Hunter College, City University of New York, New York, NY, 10031 USASearch for more papers by this author Gary G. Scott, Gary G. Scott WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UKSearch for more papers by this authorPaul J. McKnight, Paul J. McKnight Macphie of Glenbervie, Stonehaven, AB39 3YG ScotlandSearch for more papers by this authorTell Tuttle, Corresponding Author Tell Tuttle WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UKSearch for more papers by this authorRein V. Ulijn, Corresponding Author Rein V. Ulijn WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UK Advanced Science Research Center (ASRC) and Hunter College, City University of New York, New York, NY, 10031 USASearch for more papers by this author First published: 11 February 2016 https://doi.org/10.1002/adma.201670042Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract A series of tripeptides are shown by T. Tuttle, R. V. Ulijn, and co-workers to stabilize oil-in-water emulsions with highly tunable properties in work presented on page 1381. Using a combination of simulations and experiments, they show that two types of emulsions may be produced depending on peptide sequence, either forming stable interfacial nanofiber networks or more conventional surfactant-like monolayers. These biodegradable emulsifiers have direct applications in cosmetics and food science. Citing Literature Volume28, Issue7February 17, 2016Pages 1329-1329 RelatedInformation

Peptides that self-assemble into nanostructures are of tremendous interest for biological, medical, photonic and nanotechnological applications. The enormous sequence space that is available from 20 amino acids probably harbours many interesting candidates, but it is currently not possible to predict supramolecular behaviour from sequence alone. Here, we demonstrate computational tools to screen for the aqueous self-assembly propensity in all of the 8,000 possible tripeptides and evaluate these by comparison with known examples. We applied filters to select for candidates that simultaneously optimize the apparently contradicting requirements of aggregation propensity and hydrophilicity, which resulted in a set of design rules for self-assembling sequences. A number of peptides were subsequently synthesized and characterized, including the first reported tripeptides that are able to form a hydrogel at neutral pH. These tools, which enable the peptide sequence space to be searched for supramolecular properties, enable minimalistic peptide nanotechnology to deliver on its promise.

We demonstrate the preparation of peptide gel microparticles that are emulsified and stabilized by SiO2 nanoparticles. The gels are composed of aromatic peptide amphiphiles 9-fluorenylmethoxycarbonyldiphenylalanine (Fmoc-FF) coassembled with Fmoc-amino acids with different functional groups (S: serine; D: aspartic acid; K: lysine; and Y: tyrosine). The gel phase provides a highly hydrated matrix, and peptide self-assembly endows the matrix with tunable chemical environments which may be exploited to support and stabilize proteins. The use of Pickering emulsion to stabilize these gel particles is advantageous through avoidance of surfactants that may denature proteins. The performance of enzyme lipase B immobilized in pickering/gel microparticles with different chemical functionalities is investigated by studying transesterification in heptane. We show that the use of Pickering particles enhances the performance of the enzyme, which is further improved in gel-phase systems, with hydrophilic environment provided by Fmoc-FF/S giving rise to the best catalytic performance. The combination of a tunable chemical environment in gel phase and Pickering stabilization described here is expected to prove useful for areas where proteins are to be exploited in technological contexts such as biocatalysis and also in other areas where protein performance and activity are important, such as biosensors and bioinspired solar fuel devices.