[28] Oxygen-evolving photosystem II particles from Phormidium laminosum

Bendall, Derek S.; Bowes, Jane M.; Stewart, Ann; Taylor, M.

doi:10.1016/0076-6879(88)67031-5

Cited by 15 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pelleted thylakoid membranes were gently resuspended in ice-cold glycine betaine-containing MCM buffer [20 mM MES-NaOH (pH 6.0), 20 mM CaCl 2 , 10 mM MgCl 2 , and 0.5 M glycine betaine for T. elongatus and 50 mM MES-NaOH (pH 6.0), 10% (v/v) glycerol, 1.2 M glycine betaine, 20 mM CaCl 2 , and 5 mM MgCl 2 for for Synechococcus sp. PCC 7002] to a chlorophyll concentration of 1−1.5 mg mL −1 before being snap-frozen in liquid nitrogen and stored at −80 °C (acetone-based chlorophyll assay 64 ). All steps of the PSII preparations, handling, and storage of the samples were performed under dim green safety light or in complete darkness.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

et al. 2017

View full text Add to dashboard Cite

The identity and rearrangements of substrate water molecules in photosystem II (PSII) water oxidation are of great mechanistic interest and addressed herein by comprehensive analysis of NH/NH binding. Time-resolved detection of O formation and recombination fluorescence as well as Fourier transform infrared (FTIR) difference spectroscopy on plant PSII membrane particles reveals the following. (1) Partial inhibition in NHCl buffer occurs with a pH-independent binding constant of ∼25 mM, which does not result from decelerated O formation, but from complete blockage of a major PSII fraction (∼60%) after reaching the Mn(IV) (S) state. (2) The non-inhibited PSII fraction advances through the reaction cycle, but modified nuclear rearrangements are suggested by FTIR difference spectroscopy. (3) Partial inhibition can be explained by anticooperative (mutually exclusive) NH binding to one inhibitory and one non-inhibitory site; these two sites may correspond to two water molecules terminally bound to the "dangling" Mn ion. (4) Unexpectedly strong modifications of the FTIR difference spectra suggest that in the non-inhibited PSII, ammonia binding obliterates the need for some of the nuclear rearrangements occurring in the S-S transition as well as their reversal in the O formation transition, in line with the carousel mechanism [Askerka, M., et al. (2015) Biochemistry 54, 5783]. (5) We observe the same partial inhibition of PSII by NHCl also for thylakoid membranes prepared from mesophilic and thermophilic cyanobacteria, suggesting that the results described above are valid for plant and cyanobacterial PSII.

show abstract

Section: ■ Materials and Methodsmentioning

confidence: 99%

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The cultures were kept in glass flasks thermostatically maintained at 28°C, illuminated with cool white fluorescent light (80 μmol photons m −2 s −1 ) and bubbled with sterile air. Growth of the cultures was monitored by measurement of chlorophyll a (Bendall et al , 1988), cell number and dry mass content. Cell number per mL was determined from 5 μL culture samples in triplicate (all cells of filaments were counted microscopically).…”

Section: Methodsmentioning

confidence: 99%

Alteration of cylindrospermopsin production in sulfate- or phosphate-starved cyanobacteriumAphanizomenon ovalisporum

Bácsi

Vasas

Surányi

et al. 2006

FEMS Microbiology Letters

View full text Add to dashboard Cite

The effect of sulfate and phosphate deprivation on cell growth and cylindrospermopsin level was studied in Aphanizomenon ovalisporum ILC-164. Sulfate starvation induced a characteristic reduction of cylindrospermopsin pool size on the basis of cell number and unit of dry mass of culture. Phosphorous starvation of A. ovalisporum cultures induced a lesser reduction of cylindrospermopsin pool size. This divergence in the pool size of cylindrospermopsin may be the consequence of different growth rate. To show the metabolic changes concomitant with reduction of cylindrospermopsin pool size were obtained by measurement of ATP sulfurylase and alkaline phosphatase activity. The present study is the first concerning the cylindrospermopsin content under sulfate starvation and discusses it in relation to phosphorous starvation.

show abstract

“…Between samples, the electrode was scrubbed with NaHCO3 powder and, if inhibitors had just been used, washed with ethanol. Spheroplasts were prepared as described by Mi et al (1994) based on the protocol developed by Bendall et al (1988).…”

Section: Methodsmentioning

confidence: 99%

Interaction of the photosynthetic and respiratory electron transport chains producing slow O2 signals under flashing light in Synechocystis sp. PCC 6803

1995

View full text Add to dashboard Cite

We investigated the slow signal of apparent O2 release under brief light flashes by using mutants of Synechocystis sp. PCC 6803 which lacked CP43 and D1. The slow signal was present at higher amplitudes in the mutants. It was inhibited by starving the mutants of glucose (>90%), by 10 mM NaN3 (85%) and by boiling samples for 2 min (100%). In the mutants and in the wild-type, the slow signal was 95% inhibited by the combination of DBMIB (2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone) and HQNO (2-n-heptyl-4-hydroxyquinoline-N-oxide). In the wild type, the addition of DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) or CCCP (carbonylcyanide m-chlorophenylhydrazone) completely inhibited photosynthetic O2 evolution, yet failed to inhibit the slow signal. We explain the kinetics of the wild-type signal as a positive deflection due to the inhibition of respiration by PS I activity, and a negative deflection due to the stimulation of respiration by electrons originating from PS II. We found no evidence of a 'meta-stable S3' in Synechocystis sp. PCC 6803 that could contribute to the slow signal of apparent O2 release. We present a calculation which involves only averaging, division and subtraction, that can remove the contribution of the slow signal from the true photosynthetic O2 signal and provide up to a 10-fold improved accuracy of the S-state models.

show abstract

[28] Oxygen-evolving photosystem II particles from Phormidium laminosum

Cited by 15 publications

References 18 publications

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

Alteration of cylindrospermopsin production in sulfate- or phosphate-starved cyanobacteriumAphanizomenon ovalisporum

Interaction of the photosynthetic and respiratory electron transport chains producing slow O2 signals under flashing light in Synechocystis sp. PCC 6803

Contact Info

Product

Resources

About

[28] Oxygen-evolving photosystem II particles from Phormidium laminosum

Cited by 15 publications

References 18 publications

Inhibitory and Non-Inhibitory NH3 Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

Inhibitory and Non-Inhibitory NH3 Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

Alteration of cylindrospermopsin production in sulfate- or phosphate-starved cyanobacteriumAphanizomenon ovalisporum

Interaction of the photosynthetic and respiratory electron transport chains producing slow O2 signals under flashing light in Synechocystis sp. PCC 6803

Contact Info

Product

Resources

About

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules

Inhibitory and Non-Inhibitory NH₃ Binding at the Water-Oxidizing Manganese Complex of Photosystem II Suggests Possible Sites and a Rearrangement Mode of Substrate Water Molecules