FLASH INDUCED OSCILLATION OF THE LOW TEMPERATURE THERMOLUMINESCENCE BAND Zv IN CHLOROPLASTS

Using preilluminating flashes at 2°C prior to continuous excitation of isolated chloroplasts at -80°C, a period-four oscillation with maxima at the 0th, 4th and 8th flashes was observed in the amplitude of the thermoluminescence band Z_v. Inactivation of the water-splitting system by hydroxylamine- or Tris-treatments greatly diminished the Z_v band. On the other hand, its amplitude was not considerably affected by the addition of inhibitory concentration of DCMU. On the basis of the results, the possible origin of the Z_v band is discussed.     

ANTIGENICITY OF DNA INDUCED BY PHOTOADDITION OF 8-METHOXYPSORALEN

Abstract— Rabbits immunized with sonicated DNA UV-irradiated (365 nm) in the presence of 8-methoxypsoralen (8-MOP) produced a specific antiserum directed against DNA-8-MOP-photoadduct. None of the long chain DNA preparations modified photochemically in the same way elicited an immunological response, although all of them gave a positive immunodiffusion test on agarose with the antiserum directed against DNA-8-MOP-photoadduct. A positive reaction has also been demonstrated in the indirect immunofluorescence test, using as a source of cellular native DNA Crithidia luciliae cells treated with 8-MOP and irradiated at 365 nm (UVA). A possible use of the specific antiserum for detecting the formation of DNA-8-MOP-photoadduct, in the skin and/or lymphocytes of patients with psoriasis treated by combination of 8-MOP and UVA irradiation, is suggested.