Bioorganic and Bioinorganic Chemistry

Abstract

The interdisciplinary projects in bioinorganic and bioorganic chemistry of the Department of Chemistry, University of Basel led to the preparation of new systems that mimic biologically important processes and to the discovery of compounds from natural sources which are very promising with respect to medical applications. The advances in these areas are reported here. The Constable-Housecroft group is involved in biomimetic and bioinspired chemistry primarily relating to the fundamental processes in nature with a target of designing functional systems of sufficient robustness for practical application. This overview concentrates upon chemical approaches to the splitting of water into H 2 and O 2 based upon biomimetic or bioinspired principles. Other activities within the group involve the tagging of biomolecules with luminescent metal complexes for intracellular studies (with Prof. Matthias Wymann, Department of Biomedicine) and the deployment of nanoparticles functionalised with laccase for water purification (with Prof. Uwe Pieles, FHNW). The group has adopted a general strategy of mimicking the biological membrane by using two-dimensional control of the self-assembly of multiple components at solid-liquid or solid-air interfaces.The ultimate aim for energy production is a coupled water-splitting reaction using solar energy to generate H 2 and O 2 followed by recombination of the two diatomics in a fuel cell. The formal process is presented in Fig. 1 which serves to highlight the features that need to be controlled. Water oxidation and reduction reactions will take place at spatially separated sites and the kinetics of charge separation will be critical in controlling the success of the devices. The device can be purely molecular or the oxidation and reduction equivalents could be holes and electrons in the valence and conduction bands of a semiconductor or a combination of both approaches.For the water reduction process the group has taken inspiration from the Fe 2 S 2 structural motif found in Fe-Fe hydrogenases and invested significant synthetic Biomimetic Splitting of WaterEdwin C. Constable and Catherine E. Housecroft Evolutionary Rules for Metalloenzyme Design Marc CreusCurrent work within the newlyestablished Creus group is based on the concept that direct metal coordination to non-catalytic proteins may lead to nascent metalloenzymes, which can form a basis for further evolution. Conceptually, the dual ideas of 'emergence' and 'evolution' of metalloenzymes correspond to two extremes of an evolutionary process: i) a qualitative step, involving a new function reached through innovation (e.g. acquisition of catalytic activity from previously inactive form) and ii) a quantitative step (e.g. the improvement of a weak, but detectable function). Directed evolution, despite its limitations in practical terms, [1] provides a powerful tool for the second type (or quantitative) step. [2] Although the study of intermediate steps of improvement of metalloenzymes is likely to contribute greatly to the ...

Comparison of the π-stacking properties of purine versus pyrimidine residues. Some generalizations regarding selectivity

“…Of course, p-p stacking also occurs in proteins [13], e.g., between the indole side chain of tryptophan and the imidazole residue of histidine [14]. Moreover, stacking interactions are important for charge transfer in proteins [15][16][17] and also in the double helix of DNA [18][19][20]. Furthermore, stacking and hydrophobic interactions are of relevance for the formation of protein-nucleic acid adducts [21][22][23].…”

Extent of Intramolecular π Stacks in Aqueous Solution in Mixed‐Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1‐[2‐(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)[1, 2]

“…[9,10,[17][18][19][20] The roles of the latter ones for the structures of DNA [21,22] and RNA, [23,24] but also for proteins [25,26] are well appreciated. Indeed, stacking is important for charge transfer in proteins [26][27][28] and also in the double helix of DNA. [29] There are also more subtle observations, like stacking interactions being crucial for fluorescence quenching between nucleobases [30] or for the metal ion-promoted hydrolysis of purine-nucleoside 5Ј-triphosphates.…”