ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Ferredoxin isolated from a blue-green alga, Nostoc sp., was purified and crystallized. The absorption spectrum of Nostoc ferredoxin had, in the oxidized state, peaks at 276, 331, 423, and 470 nm, a pattern characteristic of chloroplast-type ferredoxin. The 423:276 absorption ratio was 0.57. The midpoint oxidation-reduction potential of Nostoc ferredoxin was found to be –406 mV, at pH 7.5. Nostoc ferredoxin mediated the photoreduction of NADP by isolated Nostoc chromato-phores and spinach chloroplasts from which the native ferredoxin was removed. The molar ratio of Nostoc ferredoxin to chlorophyll a was about 1:50, a ratio higher than usually found in photosynthetic cells.The possible evolutionary significance of the properties of Nostoc ferredoxin compared with those of ferredoxins from other photosynthetic organisms is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1971.tb01102.x
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