Structural and Funtional Studies on VitaminB1-Dependent Human and Bacterial Transketolases

Abstract

Acknowledgements 3.4.3.6. The Protonation State of DHEThDP Intermediate in EcTK-Indications for the Presence of Cofactors´ 1´-4´-Imino Tautomeric State 3.4.3.7. X-ray Structure of the DHEThDP Analouge 1,2 dihydroxyethy-3-deaza-Thiamin Diphosphate bound to hTK 3.4.4. Strain in Enzymatic Catalysis -Covalent Reaction Intermediates in TK 3.4.5. Limitations for Locating Hydrogen Positions by X-ray Crystallography -Outlook for Further Studies on Transketolases 3.4.6. Acceptor Substrate Binding in hTK and EcTK 3.4.6.1. Binding of E4P to hTK 3.4.6.2. Binding of E4P to EcTK 3.4.6.3. Binding of R5P to hTK 3.4.6.4. Usage of R5P Analogues Rib5P and 1desR5P 3.4.6.5. Binding of Rib5P to hTK 3.4.6.6. Binding of 1desR5P to hTK 3.4.6.7. Furanose Ring-Opening of R5P bound to EcTK -Proposal for an Acid/Base Mechanism 3.4.6.8. X-ray Structure of EcTK His 473 Ala in Non-Covalent Complex with R5P 3.4.6.9. Binding of Rib5P and 1desR5P to EcTK-A Structural and Thermodynamical Analysis 3.4.6.10.