Irradiation of small phytochrome from oat in its Pr form with 15 ns laser pulses of different wavelengths(605–655 nm) gave rise to a difference absorption with maxima at 400 and 685 nm for the first detectable transient. Bleaching of a 660 nm band was observed, non-recuperable up to 1 ms. The transient absorption has a lifetime of 70±15 μs at 273 K. The transient is tentatively identified as lumi-R and the conformation of its chromophore is postulated to be more extended than that of Pr. A deviation from the exponential decay of the lumi-R absorption at 284 and 300 K and the lack of observable enhancement of the far-red absorption within 1 ms are interpreted in terms of the appearance of still other intermediates on this time scale between lumi-R and Pfr phytochrome.
|Journal||Photochemistry and Photobiology|
|Publication status||Published - 1980|
Braslavsky, S. E., Matthews, J. I., Herbert, H. J., de Kok, J., Spruit, C. J. P., & Schaffner, K. (1980). Characterization of a microsecond intermediate in the laser flash Photolysis of small Phytochrome from oat. Photochemistry and Photobiology, 31, 417-420. https://doi.org/10.1111/j.1751-1097.1980.tb02562.x