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The photocatalytic sulfoxidation on TiO2 discovered by Parrino et al. represents a new, interesting and lower energy route for the synthesis of sulfonic acids.

Abstract The atomistic description of the folding process of a structureless chain of amino acids to a functioning protein is still considered to be a challenge for computational biophysics. An in-depth understanding of protein-folding can be achieved through atomistic dynamics accounting for the solvent effects, combined with the theoretical description of conformational changes in shorter polypeptide chains. The present paper studies the folding transitions in short polypeptide chains consisting of 11 alanine residues in explicit solvent employing all-atom molecular dynamics. The multiple observed folding $$\leftrightarrow $$ ↔ unfolding events of the peptide are interpreted as a dynamic process and rationalised through the analysis of the potential energy surface of the system. It is demonstrated that alanine polypeptide folding dynamics is governed by the backbone dihedral angles and involves the formation of spontaneously folded $$\alpha $$ α -helices which emerge and live for ca. 1–20 picoseconds. The helical content within the polypeptide at different temperatures was quantified through a statistical mechanics approach, which showed a reasonable agreement with the results of molecular dynamics simulations and experiments performed for alanine-rich peptides. Graphical abstract

Abstract Although the general mechanism for serine protease catalysis is well established, some questions still remain. For instance, the two enzymes, neutrophil elastase and cathepsin G, have a lot of structural resemblances. However, elastase degrades virulence factors, while cathepsin G does not. This paper studies both enzymes computationally to probe for their conformational differences. In the process, a methodology is established to not only quantify similarities between the protein trajectories describing proteins’ temporal evolution but also account for a varying number of amino acid residues comprising each structure. Our results indicate slight differences in the behavior of the active sites of neutrophil elastase and cathepsin G in the solvent. These subtle changes could indicate differences in the general behavior responsible for the different specificity of the two enzymes. Graphical abstract

Biological processes involve movements across all measurable scales. Similarity measures can be applied to compare and analyze these movements but differ in how differences in movement are aggregated across space and time. The present study reviews frequently-used similarity measures, such as the Hausdorff distance, Frechet distance, Dynamic Time Warping, and Longest Common Subsequence, jointly with several measures less used in biological applications (Wasserstein distance, weak Fréchet distance, and Kullback-Leibler divergence), and provides computational tools for each of them that may be used in computational biology. We illustrate the use of the selected similarity measures in diagnosing differences within two extremely contrasting sets of biological data, which, remarkably, may both be relevant for magnetic field perception by migratory birds. Specifically, we assess and discuss cryptochrome protein conformational dynamics and extreme migratory trajectories of songbirds between Alaska and Africa. We highlight how similarity measures contrast regarding computational complexity and discuss those which can be useful in noise elimination or, conversely, are sensitive to spatiotemporal scales.

This short review reports the surprising phenomenon of nuclear hyperpolarization occurring in chemical reactions, which is called CIDNP (chemically induced dynamic nuclear polarization) or photo-CIDNP if the chemical reaction is light-driven. The phenomenon occurs in both liquid and solid-state, and electron transfer systems, often carrying flavins as electron acceptors, are involved. Here, we explain the physical and chemical properties of flavins, their occurrence in spin-correlated radical pairs (SCRP) and the possible involvement of flavin-carrying SCRPs in animal magneto-reception at earth’s magnetic field.

In the present manuscript we used atomistic simulation methodsto investigate the adsorption of GGG on the titania rutile-(110)surface. The molecule showed a high adsorption to the surface es-pecially in its bidentate-⊥mode. This configuration was furtherinvestigated both in terms of charge transfer and strain analysis.In the first case a transfer of roughly one electron was observedfrom the functional groups binding to the surface atoms, leavingthe molecule at the phosphate and carboxylic groups. This chargeis distributed into the rutile’s bulk, where it gets then dissipated.To get a hint on the location of the bond break, the strain analysis identified the C-C bond as the major strain location. This presump-tion can not be confirmed in this work. In order to understand pho-tocaltalytic degradation of GGG in further investigations, a clustermodel was developed for TD-DFT simulations. The cluster simu-lations are in good agreement with the DFT simulations in termsof ground state properties (band gap and HOMO-levels) as well as geometrically optimized structures. Here not only the DOS showeda reduction of the band gap upon adsorption, but also the TD-DFTspectrum lied in the same regime. Hence, there is a high likelihoodfor GGG to proceed in a photocatalytic reaction

Multinuclear transition metal complexes bridged by ligands with extended π‐electronic systems show a variety of complex electronic transitions and electron transfer reactions. While a systematic understanding of the photochemistry and electrochemistry has been attained for binuclear complexes, much less is known about trinuclear complexes such as hexaphenyl‐5,6,11,12,17,18‐hexaazatrinaphthylene‐tristitanocene [(Cp2Ti)3HATN(Ph)6]. The voltammogram of [(Cp2Ti)3HATN(Ph)6] shows six oxidation and three reduction waves. Solution spectra of [(Cp2Ti)3HATN(Ph)6] and of the electrochemically formed oxidation products show electronic transitions in the UV, visible and the NIR ranges. Density functional theory (DFT) and linear response time‐dependent DFT show that the three formally titanium(II) centers transfer an electron to the HATN ligand in the ground state. The optically excited transitions occur exclusively between ligand‐centered orbitals. The charged titanium centers only provide an electrostatic frame to the extended π‐electronic system. Complete active self‐consistent field (CASSCF) calculation on a structurally simplified model compound, which considers the multi‐reference character imposed by the three titanium centers, can provide an interpretation of the experimentally observed temperature‐dependent magnetic behavior of the different redox states of the title compound in full consistency with the interpretation of the electronic spectra., More complex?! The ground state of the three‐nuclear [(Cp2Ti)3HATN(Ph)6] complex is formed by spin states of different multiplicity and explains the rich electronic transition in the UV‐vis‐NIR ranges in different charge states. Contrary to common notion, IVCT transitions do not play a role in the NIR spectra.