By applying microspectrophotometry to the sporangiophore of Phycomyces blakesleeanus wild-type and the albino car-10(-) type II, absorption spectra were obtained for 1- to 5-day cultures. Spectra in the growing-zone of the wild-type during Stage IVb, taken from 0.1 to 3 mm below the base of the sporangium, show two distinctly different spectra: one is more characteristic of a carotene, the other of a flavin. Combined, these absorption spectra reproduce closely the action spectrum. For the albino car-10(-), which is deficient in carotenes, only the spectrum characteristic of lumichrome or a reduced flavin was found. A c-type cytochrome was isolated from both strains which, if coupled with a flavin, could permit a photoreversible oxidation-reduction system. Birefringent crystals were observed to be aligned in the growing zone in which the photoreceptor is believed to lie. Micro-spectrophotometry of these crystals shows absorption peaks similar to those of riboflavin crystals.
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Article| November 01 1969
MICROSPECTROPHOTOMETRY AND THE PHOTORECEPTOR OF PHYCOMYCES I
Jerome J. Wolken
From the Biophysical Research Laboratory, Carnegie Institute of Technology, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213
Received: May 05 1969
Revision Received: June 28 1969
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Copyright © 1969 by The Rockefeller University Press.
Jerome J. Wolken; MICROSPECTROPHOTOMETRY AND THE PHOTORECEPTOR OF PHYCOMYCES I . J Cell Biol 1 November 1969; 43 (2): 354–360. doi: https://doi.org/10.1083/jcb.43.2.354
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