TY - JOUR
T1 - A Spectroscopic Analysis of a High Fluorescent Mutant of Chlamydomonas Reinhardi
AU - Epel, B. L.
AU - Butler, W. L.
N1 - Funding Information:
This work was supported by National Institutes of Health grant GM-15048 to Dr. Butler, a Na- tional Institutes of Health Postdoctoral Fellowship to Dr. Epel, and a National Science Foundation grant GB-11792 to Professor R. P. Levine in whose laboratory the mutants were isolated.
PY - 1972
Y1 - 1972
N2 - Chloroplast fragments of a high fluorescent mutant of Chlamydomonas reinhardi, hfd 91, were compared against those of Acl+, a low chlorophyll variant of the wild type. The chloroplast fragments of the mutant which have a high invariant fluorescence yield lacked photochemical activities associated with photosystem II (PSII) but retained normal photosystem I (PSI) activities. The mutant fragments also lacked the low temperature (-196°C) light-induced absorbance changes due to the photoreduction of C-550 and the photooxidation of cytochrome (cyt) b-559 which are PSII-mediated reactions. A fourth-derivative analysis of the absolute spectra of the chloroplast fragments at different stages of reduction (obtained with ferricyanide, ascorbate, and dithionite) showed both the oxidized and reduced forms of C-550 and the reduced forms of cyt c-553, b-559, and b-564 in wild-type fragments. The mutant fragments lacked C-550 and an ascorbate-reducible cyt b-559 but contained cyt c-553, a dithionite-reducible cyt b-559, and cyt b-564.
AB - Chloroplast fragments of a high fluorescent mutant of Chlamydomonas reinhardi, hfd 91, were compared against those of Acl+, a low chlorophyll variant of the wild type. The chloroplast fragments of the mutant which have a high invariant fluorescence yield lacked photochemical activities associated with photosystem II (PSII) but retained normal photosystem I (PSI) activities. The mutant fragments also lacked the low temperature (-196°C) light-induced absorbance changes due to the photoreduction of C-550 and the photooxidation of cytochrome (cyt) b-559 which are PSII-mediated reactions. A fourth-derivative analysis of the absolute spectra of the chloroplast fragments at different stages of reduction (obtained with ferricyanide, ascorbate, and dithionite) showed both the oxidized and reduced forms of C-550 and the reduced forms of cyt c-553, b-559, and b-564 in wild-type fragments. The mutant fragments lacked C-550 and an ascorbate-reducible cyt b-559 but contained cyt c-553, a dithionite-reducible cyt b-559, and cyt b-564.
UR - http://www.scopus.com/inward/record.url?scp=0015374728&partnerID=8YFLogxK
U2 - 10.1016/S0006-3495(72)86134-4
DO - 10.1016/S0006-3495(72)86134-4
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AN - SCOPUS:0015374728
SN - 0006-3495
VL - 12
SP - 922
EP - 929
JO - Biophysical Journal
JF - Biophysical Journal
IS - 7
ER -