Published in JACS, researchers in the Papanikolas and Waters groups, in collaboration with members of the Meyer group at Carolina Chemistry and the Papoian Group at the University of Maryland, describe how solid-phase peptide synthesis has been applied to the preparation of phosphonate-derivatized oligoproline assemblies containing two different RuII polypyridyl chromophores coupled via "click" chemistry.
In water or methanol the assembly adopts the polyproline II (PPII) helical structure, which brings the chromophores into close contact. Excitation of the assembly is followed by rapid, efficient intra-assembly energy transfer to the inner RuII. The oligoproline/click chemistry approach holds great promise for the preparation of interfacial assemblies for energy conversion based on a family of assemblies having controlled compositions and distances between key functional groups.
Researchers in the Waters Group, as described in an article published in JACS, utilized dynamic combinatorial chemistry to identify a novel small molecule receptor, A2D, for asymmetric dimethyl arginine, aRMe2, which is a post-translational modification, PTM, in proteins. It is known to play a role in a number of diseases, including spinal muscular atrophy, leukemia, lymphoma, and breast cancer.
The receptor exhibits 2.5–7.5-fold selectivity over the isomeric symmetric dimethyl arginine, depending on the surrounding sequence, with binding affinities in the low micromolar range. The affinity and selectivity of A2D for the different methylated states of Arg parallels that of proteins that bind to these PTMs. Characterization of the receptor–PTM complex indicates that cation−π interactions provide the main driving force for binding, loosely mimicking the binding mode found in the recognition of dimethyl arginine by native protein receptors.