Singular oxygen effects on the room-temperature phosphorescence of alcohol dehydrogenase from horse liver

The room-temperature phosphorescence of alcohol dehydrogenase from horse liver in the presence of oxygen has the characteristics of a light-induced emission as it appears only after a certain amount of excitation has been absorbed. The initial lag period, the steady-state intensity, and the duration of the induced state are dominated by the oxygen content of the solution, the rate of light absorption, and the radiation dose. The phenomenon is not unique to this enzyme and the data are consistent with photochemical depletion of oxygen.