Routine Method of 77Kr Production

開始ページ、終了ページ: 冊子体のページ付

The New BBB Indicator of Positron Emitting Radionuclide Tracer - 45Ti-DTPA

開始ページ、終了ページ: 冊子体のページ付

Automated Synthesis of 18F-5-Fluoro-2\u27-Deoxyuridine

開始ページ、終了ページ: 冊子体のページ付

Development of a New Automated Synthesis System of [F-18]FDG

開始ページ、終了ページ: 冊子体のページ付

Cancer Detection with 18F-5-Fluorodeoxyridine. A New Cancer Diagnostic Agent Reflecting the Nucleic Acid Metabolism

開始ページ、終了ページ: 冊子体のページ付

45Ti-DTPA and Blood-Brain Barrier

開始ページ、終了ページ: 冊子体のページ付

Engineering of Cyclodextrin Product Specificity and pH Optima of the Thermostable Cyclodextrin Glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1

The product specificity and pH optimum of the thermostable cyclodextrin glycosyltransferase (CGTase) from Thermoanaerobacterium thermosulfurigenes EM1 was engineered using a combination of x-ray crystallography and site-directed mutagenesis. Previously, a crystal soaking experiment with the Bacillus circulans strain 251 β-CGTase had revealed a maltononaose inhibitor bound to the enzyme in an extended conformation. An identical experiment with the CGTase from T. thermosulfurigenes EM1 resulted in a 2.6-Å resolution x-ray structure of a complex with a maltohexaose inhibitor, bound in a different conformation. We hypothesize that the new maltohexaose conformation is related to the enhanced α-cyclodextrin production of the CGTase. The detailed structural information subsequently allowed engineering of the cyclodextrin product specificity of the CGTase from T. thermosulfurigenes EM1 by site-directed mutagenesis. Mutation D371R was aimed at hindering the maltohexaose conformation and resulted in enhanced production of larger size cyclodextrins (β- and γ-CD). Mutation D197H was aimed at stabilization of the new maltohexaose conformation and resulted in increased production of α-CD. Glu258 is involved in catalysis in CGTases as well as α-amylases, and is the proton donor in the first step of the cyclization reaction. Amino acids close to Glu258 in the CGTase from T. thermosulfurigenes EM1 were changed. Phe284 was replaced by Lys and Asn327 by Asp. The mutants showed changes in both the high and low pH slopes of the optimum curve for cyclization and hydrolysis when compared with the wild-type enzyme. This suggests that the pH optimum curve of CGTase is determined only by residue Glu258.

11C-Coenzyme Q10: A New Myocardial-Imaging Tracer for Positron Emission Tomography

開始ページ、終了ページ: 冊子体のページ付

Current and Future Aspects of Cancer Diagnosis with Positron Emission Tomography: Biological and Clinical Aspect

開始ページ、終了ページ: 冊子体のページ付

Synthesis and Biodistribution of 11C-labeled Pargyline, an Irreversible Inhibitor of Monoamine Oxidase

開始ページ、終了ページ: 冊子体のページ付