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Effect of Tentoxin on the Activation and on the Catalytic Reaction of Reconstituted H+-ATPase from Chloroplasts

Fromme, Petra; Dahse, Ingo; Gräber, Peter

Inst. Chemie

The proton-translocating ATPase from chloroplasts, CF0F1, was isolated, purified and reconstituted into asolectin liposomes. The effect of the energy transfer inhibitor, tentoxin, on different functions of the enzyme was investigated. Tentoxin does not inhibit the nucleotide release during energization by a pH /ΔΨ jump, i.e. the activation of the enzyme is not influenced. ATP synthesis driven by a pH /ΔΨ jump and multi-site ATP hydrolysis are completely inhibited by tentoxin, whereas uni-site ATP hydrolysis is not influenced.