title: Studies on the nature of thiamine pyrophosphate binding and dependency on divalent cations of transketolase from human erythrocytes.
abstract: 1. The binding kinetics for [35S]thiamine pyrophosphate to transketolase and the dependency of transketolase on divalent cations for activity were investigated. 2. With Scatchard analysis, dissociation constant (Kd) and n value were calculated to be 0.2 x 10(-6) M and 0.66 respectively. 3. The activity of the reconstituted enzyme increased in the order of Co2+ less than Mn2+ less than Ca2+ less than Mg2+. The native transketolase contained Mg2+ in its molecular structure.
authors.affiliation: Department of Hygiene, Faculty of Medicine, Kyoto University, Japan.
authors.forename: E H
authors.initials: EH
authors.lastname: Jung
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
authors.forename: K
authors.initials: K
authors.lastname: Nishino
authors.forename: Y
authors.initials: Y
authors.lastname: Itokawa
mesh_terms: D001665:Binding Sites / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D002384:Catalysis; D004789:Enzyme Activation / Q000187:drug effects; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D013835:Thiamine Pyrophosphate / Q000097:blood*; D014174:Transketolase / Q000097:blood*
chemical_list: D008345:Manganese; D014174:Transketolase; D008274:Magnesium; D013835:Thiamine Pyrophosphate; D002118:Calcium