Studies on the nature of thiamine pyrophosphate binding and dependency on divalent cations of transketolase from human erythrocytes.
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.
Jung
E H
EH
Department of Hygiene, Faculty of Medicine, Kyoto University, Japan.
Takeuchi
T
T
Nishino
K
K
Itokawa
Y
Y
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*
D008345:Manganese; D014174:Transketolase; D008274:Magnesium; D013835:Thiamine Pyrophosphate; D002118:Calcium