Organic & Biomolecular Chemistry Blog

While protein assemblies are key to biological processes, their mis-assembly often leads to altered functions such as those found in neurodegenerative diseases. Considerable efforts are ongoing towards the understanding of the assembly processes, either using native or artificial systems.

In this OBC Hot article, Mingming Ma and Dennis Bong at the Ohio State University (Columbus, USA) construct a protein-protein artificial interface and demonstrate that when functionalized with synthetic cyanuric acid and melamine, the streptavidin proteins are able to assemble selectively, based on reversible supramolecular recognition. Such synthetic modules could be used to direct the molecular interactions for the construction of novel biomaterials and functional molecular assemblies.

Interested in proteins, biomaterials or supramolecular chemistry? This OBC Communication is for you!

FREE to access for a period of 4 weeks.

Protein assembly directed by synthetic molecular recognition motifs
Mingming Ma and Dennis Bong
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C1OB05998J, Communication

Sabine Schlecht and colleagues from the Free University of Berlin have designed a series of sulfated cyclic and acyclic amino alcohols bound to colloidal gold nanoparticles for use as multivalent selectin binding agents.  The carbohydrate mimics were chosen to act as simplified analogs of the sLe^x unit found in biological selectin ligands, and demonstrated extremely high binding affinities towards L- and P-selectin and no cytotoxicity.

To read the details of this well conducted study download the article – it’s free to access for 4 weeks:

Multivalent interaction and selectivities in selectin binding of functionalized gold colloids decorated with carbohydrate mimetics
Meike Roskamp, Sven Enders, Fabian Pfrengle, Shahla Yekta, Vjekoslav Dekaris, Jens Dernedde, Hans-Ulrich Reissig and Sabine Schlecht
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C1OB05583F

β-lactones are potentially useful as drugs for several diseases, due to their ability to inhibit key biological functions.  However, their high reactivity in physiologically relevant conditions also renders their half-life very short and limits the potential drug applications.

To combat this David Crich and colleagues at the Institut de Chimie des Substances Naturelles, CNRS, have synthesised a series of β-thiolactone analogs of β-lactones, on the basis that they would have greater persistence in aqueous media without too much loss of reactivity with the intended targets, as compared to β-lactam analogues.  The synthesised β-thiolactones were assayed for cytotoxicity against several human cancer cell lines, where they showed greater activity than the corresponding lactones and lactams.

Interested? The article is free to access for 4 weeks:

Exploring the potential of the β-thiolactones in bioorganic chemistry
Sylvain Aubry, Kaname Sasaki, Laure Eloy, Geneviève Aubert, Pascal Retailleau, Thierry Cresteil and David Crich
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C1OB05967J

Arindam Banerjee and collaborators at the Indian Institute of Chemical Biology and Indian Association for the Cultivation of Science in Jadavpur (India) demonstrate the spontaneous formation of hierarchical vesicle-in-vesicle systems from remarkably simple peptides.

These multivesicular structures are stable over a wide pH range (2 to 12) and can encapsulate anticancer drugs and fluorescent dyes, while the release is triggered by biocompatible Ca2+ ions. Combined with a negligible cytotoxicity, these peptide based functional vesicles hold future promise as biocompatible delivery vehicles.

This article has been selected as HOT and will be free to access for the next 4 weeks. Why not read it now!

Self-assembling dipeptide-based nontoxic vesicles as carriers for drugs and other biologically important molecules Jishu Naskar, Subhasish Roy, Anindita Joardar, Sumantra Das and Arindam Banerjee
Org. Biomol. Chem., 2011, 9, 6610-6615
DOI: 10.1039/C1OB05757J, Paper

Victor Pike and colleagues from the National Institute of Mental Health in Bethesda (Maryland, USA) have devised novel and efficient methods to readily access 18F-labelled mGluR5 PET radioligands that are useful for molecular imaging with positron emission tomography (PET).

While iodonium based compounds are considered promising for the preparation of PET radiotracers, very few examples of applications have been realised so far. Now, Pike and colleagues have designed appropriate diaryliodonium tosylates as precursors for introducing fluorine-18 into simple arenes to radiosynthesise standard PET radiotracers. These would otherwise be poorly accessible via traditional aromatic nucleophilic substitution reactions with the [18F]fluoride ion, due to the weak activation of the aryl ring.

The referees and the OBC Editorial office very much enjoyed this excellent paper, and we hope you will too! Read it for FREE for the next 4 weeks.

Syntheses of mGluR5 PET radioligands through the radiofluorination of diaryliodonium tosylates
Sanjay Telu, Joong-Hyun Chun, Fabrice G. Siméon, Shuiyu Lu and Victor W. Pike
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C1OB05555K, Paper

This hot article from Julio Casado and colleagues at the University of Salamanca provides the first study of the alkylating ability of p-nitrostyrene oxide (pNSO), which is widely used in the pharmaceutical industry as a chiral building block for a variety of drugs.  pNSO is also used as a substrate to study the activity of epoxide hydrolases and in polymer production.

4-(p-nitrobenzyl)pyridine (NBP), a model nucleophile for DNA bases, was used to study the alkylating effects of pNSO.  They found that although pNSO is a strong alkylating agent, it has low efficacy – probably due to the instability of the  NBP-pNSO adduct formed.  A previously unreported pNSO-guanosine adduct was also detected.

For the full details of this interesting study download the article – it’s currently free to access for 4 weeks:

Reactivity of p-nitrostyrene oxide as an alkylating agent. A kinetic approach to biomimetic conditions
Marina González-Pérez, Rafael Gómez-Bombarelli, M. Teresa Pérez-Prior, José A. Manso, Isaac F. Céspedes-Camacho, Emilio Calle and Julio Casado
Org. Biomol. Chem., 2011, Advance Article
DOI: 10.1039/C1OB05909B