Before revision:  While ETp across holo-Az at low force (6 nN) is temperature-independent over the whole examined range, ETp across apo-Az is thermally activated , with calculated activation energy of 600 meV.
After revision:  While ETp across holo-Az at low force (6 nN) is temperature-independent to thermally activated at high temperatures. This is in contrast to the Cu-depleted form of Az ( apo-Az is thermally activated , with calculated activation energy of 600 meV.