Climate change is one of the largest challenges faced by humanity. To combat this research into alternatives to fossil fuels is ongoing. Dihydrogen is considered a good alternative fuel, since its... Show moreClimate change is one of the largest challenges faced by humanity. To combat this research into alternatives to fossil fuels is ongoing. Dihydrogen is considered a good alternative fuel, since its burning only forms water. A promising means of acquiring dihydrogen is photocatalysis, which can be driven by sunlight. This involves water oxidation and proton reduction, both half-reactions require a catalyst and photosensitizer, generally metal complexes. The limited aqueous solubility and stability of these complexes poses a challenge in their application. In this thesis we investigated the use artificial metalloenzymes (ArMs) for the catalysis and photosensitization of both half-reactions. ArMs can improve the aqueous solubility of these catalysts and provide a second coordination sphere that can be used to improve the stability and activity. The ArMs in this thesis were prepared using the axial coordination of a catalyst or photosensitizer to a protein via histidine. We set up an effective screening method for this coordination using semi-native PAGE. We then prepared and characterized one of the first ArMs with photocatalytic water oxidation activity. We prepared eight photosensitizing ArMs, of which two also able to catalyse hydrogen evolution. Two of these ArM systems were entirely earth-abundant metal-based and showed good activity. Show less
Protein-protein interactions play an important role in all cellular processes such as signal transduction, electron transfer, gene regulation, transcription, and translation. Understanding these... Show moreProtein-protein interactions play an important role in all cellular processes such as signal transduction, electron transfer, gene regulation, transcription, and translation. Understanding these protein-protein interactions at the molecular level, is an important aim in structural biology. The protein interactions studied in this work are principally involved in the signal transduction and in electron transfer. These protein interactions belong to the family of transient dynamic interactions, meaning they associate and dissociate rapidly. The work presented in chapters two and three gives a detailed description of a study to determine the binding orientation of focal adhesion kinase derived peptide on the Src SH3 domain using paramagnetic NMR spectroscopy. The work presented in chapter four gives detailed information on the cloning, expression and purification of the focal adhesion kinase domain with the SH3 and S H2 binding sequences (32k) using a baculovirus expression system. The results of NMR characterization were presented for the complexes of different Src domains and the 32k. The work presented in the chapters five and six describes the NMR characterization of the interactions between several redox proteins. The aim of the work was to convert the transiently bound weak protein complexes into specific complexes Show less
