Cover Picture: Molecular Origin of the Hydrolytic Activity and Fixed Regioselectivity of a ZrIV‐Substituted Polyoxotungstate as Artificial Protease (Chem. Eur. J. 31/2014) (2014)

A multitechnique approach has been applied to identify the thermodynamic and kinetic parameters related to the regioselective hydrolysis of human serum albumin (HSA) promoted by the Wells–Dawson polyoxometalate (POM), K15H[Zr(α2-P2W17O61)2]. In accordance with different interaction studies, hydrolysis experiments have shown four cleavage positions. Furthermore, regioselectivity at these positions was retained upon prolonged reaction times. The cover art is inspired by the work of the Belgian surrealist painter René Magritte. The ZrIV-substituted Wells–Dawson structure is presented in the center, surrounded by the four cleavage positions to which it shows regioselective hydrolytic activity. For more details, see the Full Paper by T. N. Parac-Vogt et al. on page 9567 ff. A multitechnique approach has been applied to identify the thermodynamic and kinetic parameters related to the regioselective hydrolysis of human serum albumin (HSA) promoted by the Wells–Dawson polyoxometalate (POM), K15H[Zr(α2-P2W17O61)2]. In accordance with different interaction studies, hydrolysis experiments have shown four cleavage positions. Furthermore, regioselectivity at these positions was retained upon prolonged reaction times. The cover art is inspired by the work of the Belgian surrealist painter René Magritte. The ZrIV-substituted Wells–Dawson structure is presented in the center, surrounded by the four cleavage positions to which it shows regioselective hydrolytic activity. For more details, see the Full Paper by T. N. Parac-Vogt et al. on page 9567 ff. MicroRNA Quantification Accurate and sensitive quantification of microRNAs is fundamental in the clinical praxis when using these short, noncoding RNAs as biomarkers for pathological conditions. MicroRNA quantification based on nanotechnology may offer several advantages compared to commonly used strategies, including high sensitivity, specificity, and cost effectiveness. In their Review on page 9476 ff., R. Fiammengo et al. summarize the achievements in this field and discuss nanoparticle-based approaches in solution, sensing based on nanostructured surfaces, combined nanoparticle/surface sensing approaches, and single-molecule approaches.1 Nucleobases Where is the lone electron pair of the exocyclic amino group in an N-heterocyclic nucleobase? Usually largely delocalized into the ring and therefore not available for proton binding or metal coordination, it can also be located at the exocyclic N atom under specific conditions of hydrogen bonding or following the substitution of a proton by a metal ion. This dual-side behavior of the exocyclic amino group, here depicted for a cytosine model nucleobase, is in a sense a metaphor for the two faces of the Roman god Janus, as reflected on this old coin. For more details, see the Communication by C. Fonseca Guerra, P. J. Sanz Miguel, A. Cebollada, F. M. Bickelhaupt, and B. Lippert on page 9494 ff.1 Chiroptical Properties Remarkable chiroptical responses are a hallmark of enantiomerically pure shape-persistent alleno-acetylenic macrocycles and acyclic alleno-acetylenic oligomers with all-carbon backbones, as shown in the investigation of a new series of such compounds described in the Full Paper by F. Diederich et al. on page 9558 ff. Support for the D2-symmetric crown-type macrocyclic structure and the folded secondary structure with right-handed helicity of the acyclic oligomer in the solid state was obtained by X-ray crystallography.1