ALFRED BENNUN, PH.D.

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Light-dependent and light-triggered adenosine triphosphatases in chloroplasts
Bennun, A. and Avron, M.


Three types of adenosine triphosphatases have been reported in chloroplasts. In the dark, chloroplasts catalyse the hydrolysis of ATP at a very low rate. This rate is substantially increased by light, and is increased even further by the presence of calcium ions. Also the addition of a sulfhydrvl reagent and magnesium ions, induce a light-dependent ATPase in chloroplasts. Recent studies by Hoch & Martin and Marchant & Packer, have demonstrated that light is necessary for the initiation of the latter ATPase activity, but not for its further functioning. A more proper term for the magnesium-, and sulfhvdryl-dependent ATPase of chloroplasts should therefore be a light-triggered ATPase.


Biochimica et Biophysica Acta, 79, (1964), 646-648