Paulina M Dominiak

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The derivative of vitamin B1, thiamin pyrophosphate, is a cofactor of enzymes performing catalysis in pathways of energy production. In alpha2beta2-heterotetrameric human pyruvate dehydrogenase, this cofactor is used to cleave the Calpha-C(=O) bond of pyruvate followed by reductive acetyl transfer to lipoyl-dihydrolipoamide acetyltransferase. The dynamic(More)
At the junction of glycolysis and the Krebs cycle in cellular metabolism, the pyruvate dehydrogenase multienzyme complex (PDHc) catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA. In mammals, PDHc is tightly regulated by phosphorylation-dephosphorylation of three serine residues in the thiamin-dependent pyruvate dehydrogenase (E1) component.(More)
Low-temperature, high-resolution X-ray studies of charge distributions in the three Schiff bases, the dianil of 2-hydroxy-5-methylisophthaldehyde, 3,5-dinitro-N-salicylidenoethylamine and 3-nitro-N-salicylidenocyclohexylamine, have been carried out. These structures exhibit interesting weak interactions, including two extreme cases of intramolecular(More)
A comprehensive version of the theoretical databank of transferable aspherical pseudoatoms is described, and its first application to protein-ligand interaction energies is discussed. The databank contains all atom types present in natural amino acid residues and other biologically relevant molecules. Each atom type results from averaging over a family of(More)
Quantum chemical DFT calculations at the B3LYP/6-31G(d) level have been used to study the stereochemical course of the photochemical cycloaddition of enone 9 with dienes. The observed products of this photochemically induced cycloaddition showed a stereoselectivity, which is opposite to what would be expected by FMO considerations. The quantum chemical(More)
Rhodium-catalyzed decomposition of aryldiazoacetates in the presence of pyrroles or furans results in mono- or biscyclopropanation of the heterocycle, but with opposite enantioinduction. In the absence of sterically encumbering groups, the cyclopropanation of furan occurs with initial bond formation at the 2-position. If this pathway is sterically blocked,(More)
The consequences of different treatments of H atoms in experimental charge-density studies are discussed. Geometric and topological parameters obtained after applying four different H-atom models in multipolar refinement on high-resolution X-ray data only were compared with the results obtained for a reference joint high-resolution X-ray/neutron refinement.(More)
High-resolution low-temperature synchrotron X-ray diffraction data of the salt L-phenylalaninium hydrogen maleate are used to test the new automated iterative Hirshfeld atom refinement (HAR) procedure for the modelling of strong hydrogen bonds. The HAR models used present the first examples of Z' > 1 treatments in the framework of wavefunction-based(More)
A high-resolution single-crystal X-ray study of paracetamol has been performed at 85 K. Different approaches to modeling the experimental electron density (ED) were tested for the dynamically disordered portions of the molecule in order to check to what extent it is possible to obtain a proper ED distribution in the ordered part. Models were examined in(More)
The accuracy of electrostatic properties estimated from the Hansen-Coppens multipolar model was verified. Tests were carried out to determine whether the multipolar model is accurate enough to study changes of electrostatic properties under the influence of a crystal field. Perturbed and unperturbed electron densities of individual molecules of amino acids(More)