Abstract：
:The early suggestion by Lozier and Butler (Photochem. Photobiol. 17, 133-137 (1973)) that EPR Signal II arises from radicals associated with the water-splitting process in PSII has been confirmed and extended over the intervening years. Recent work has identified the Signal II radicals, [Formula: see text] and [Formula: see text], with plastosemiquinone cation species. In the experiments presented here we have used ENDOR spectroscopy and D2O/H2O exchange to characterize these paramagnets in more detail. The ENDOR matrix region, which arises from protons which interact weakly with the unpaired electron spin, is well-resolved at 4 K and at least seven resonances are apparent. A number of hyperfine couplings in the 3-8 MHz range are observed and are suggested to arise from methyl or hydroxyl protons which occur as substituents on the plastosemiquinone cation ring or from amino acid protons hydrogen-bonded to the 1,4-hydroxyl groups. Orientation selection experiments are consistent with these possibilities. D2O/H2O exchange shows that the D(+)/Z(+) site is accessible to solvent. However, the exchange occurs slowly and is not complete even after 72 hours which suggests that the free radicals are functionally isolated from solvent water.
journal_name
Photosynth Resjournal_title
Photosynthesis researchauthors
Chandrashekar TK,O'malley PJ,Rodriguez I,Babcock GTdoi
10.1007/BF00118308subject
Has Abstractpub_date
1986-01-01 00:00:00pages
423-9issue
3eissn
0166-8595issn
1573-5079journal_volume
10pub_type
杂志文章abstract：:Using 77 K chlorophyll a (Chl a) fluorescence spectra in vivo, the development was studied of Photosystems II (PS II) and I (PS I) during greening of barley under intermittent light followed by continuous light at low (LI, 50 mumol m(-2) s(-1)) and high (HI, 1000 mumol m(-2) s(-1)) irradiances. The greening at HI inte...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1023/A:1020943107318
更新日期：2002-01-01 00:00:00
abstract：:The storage of light energy in chemical form through photosynthesis is the key process underlying life as we know it. To utilize photosynthates efficiently as structural materials or as fuel to drive endergonic processes, they have to be transported from where they are produced to where they are needed. In this primer...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-013-9867-5
更新日期：2013-11-01 00:00:00
abstract：:Two species-invariant tryptophan residues at positions 109 and 250 of tobacco Rubisco activase were identified by site-directed mutagenesis as being responsible for the increase in intrinsic fluorescence upon addition of ATP, which has been previously attributed to increased self-association. Substitution of W109, whi...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-006-9051-2
更新日期：2006-05-01 00:00:00
abstract：:A combination of inhibitor and (15)N studies were used to investigate the photorespiratory nitrogen cycle in maize, a C4 plant. Inhibitors used included isonicotinyl hydrazide which blocks the conversion of glycine to serine, methionine sulfoximine an inhibitor of GS and azaserine an inhibitor of GOGAT. Results from l...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00041796
更新日期：1983-01-01 00:00:00
abstract：:Bill Arnold's concept of photosynthesis as a solid state, as opposed to solution, phenomenon led him to an amazing series of fundamental discoveries. ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00040990
更新日期：1996-05-01 00:00:00
abstract：:Water vapor was added differentially to the gas streams entering the cells of three makes of differential infrared carbon dioxide analysers. Analyser deflections were compared with those expected from dilution of the carbon dioxide by the additional gas. Tests were made at 0, 365, and 730 cm(3) m(-3) concentrations of...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00054104
更新日期：1985-12-01 00:00:00
abstract：:Time-resolved (TR) infrared (IR) spectroscopy in the nanosecond to second timescale has been extensively used, in the last 30 years, in the study of photosynthetic systems. Interesting results have also been obtained at lower time resolution (minutes or even hours). In this review, we first describe the used technique...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-016-0305-3
更新日期：2017-02-01 00:00:00
abstract：:Moderate heat stress and fluctuating light are typical conditions in summer in tropical and subtropical regions. This type of stress can cause photodamage to photosystems I and II (PSI and PSII). However, photosynthetic responses to the combination of heat and fluctuating light in young leaves are little known. In thi...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-020-00754-7
更新日期：2020-06-01 00:00:00
abstract：:The genome of the purple non-sulphur photosynthetic bacterium Rhodopseudomonas acidophila has been found to contain multiple copies of puc light-harvesting (LH2) peripheral antenna complex genes. Three wild-type isolates each exhibiting dissimilar peripheral antenna complex phenotypes in response to growth at reduced ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00034783
更新日期：1996-09-01 00:00:00
abstract：:The picture presently emerging from studies on the mechanism of photosystem II electron transport is discussed. The reactions involved in excitation trapping, charge separation and stabilization of the charge pair in the reaction center, followed by the reactions with the substrates, plastoquinone reduction and water ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00032785
更新日期：1985-01-01 00:00:00
abstract：:Phycobilisomes, comprised of both chromophoric (phycobiliproteins) and non-chromophoric (linker polypeptides) proteins, are light-harvesting complexes present in the prokaryotic cyanobacteria and the eukaryotic red algae. Many cyanobacteria exhibit complementary chromatic adaptation, a process which enables these orga...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00047680
更新日期：1988-07-01 00:00:00
abstract：:Oxygenic photosynthesis requires chlorophyll (Chl) for the absorption of light energy, and charge separation in the reaction center of photosystem I and II, to feed electrons into the photosynthetic electron transfer chain. Chl is bound to different Chl-binding proteins assembled in the core complexes of the two photo...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-015-0154-5
更新日期：2015-12-01 00:00:00
abstract：:Thylakoids are complex sub-organellar membrane systems whose role in photosynthesis makes them critical to life. Thylakoids require the coordinated expression of both nuclear- and plastid-encoded proteins to allow rapid response to changing environmental conditions. Transport of cytoplasmically synthesized proteins to...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-018-0567-z
更新日期：2018-12-01 00:00:00
abstract：:NADP:ferredoxin oxidoreductase (EC. 1.6.7.1.) isolated from a thermophilic blue-green alga, Synechococcus sp., was stable at temperatures up to 65°C. The diaphorase and cytochrome c reductase activities of the enzyme were low at 25°C but increased with elevated temperature to reach a maximum at about 60°C. The pH-prof...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00020595
更新日期：1980-09-01 00:00:00
abstract：:This review describes the progress in our understanding of the structure of the Mn complex in Photosystem II over the last two decades. Emphasis is on the research from our laboratory, especially the results from X-ray absorption spectroscopy, low temperature electron paramagnetic resonance and electron spin echo enve...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00046751
更新日期：1993-01-01 00:00:00
abstract：:Chlorophyll fluorescence imaging has been used to analyse the response elicited in Phaseolus vulgaris after inoculation with Pseudomonas syringae pv. phaseolicola 1448A (compatible interaction) and P. syringae pv. tomato DC3000 (incompatible interaction). With the aim of modulating timing of symptom development, diffe...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-007-9278-6
更新日期：2008-04-01 00:00:00
abstract：:This article summarizes knowledge on genes and their respective proteins in the field of green algal hydrogen research. Emphasis is placed on recently cloned genes from the unicellular green alga Chlamydomonas reinhardtii, including HydA1 and HydA2, which encode homologous [Fe]-hydrogenases, Tla1, which encodes a chlo...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-004-2050-2
更新日期：2004-01-01 00:00:00
abstract：:Acaryochloris marina is a unique cyanobacterium that contains chlorophyll (Chl) d as a major pigment. Because Chl d has smaller excitation energy than Chl a used in ordinary photosynthetic organisms, the energetics of the photosystems of A. marina have been the subject of interest. It was previously shown that the red...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-014-0073-x
更新日期：2015-08-01 00:00:00
abstract：:Upon a sudden transition from high to low light, the rate of CO2 assimilation (AN) in some plants first decreases to a low level before gradually becoming stable. However, the underlying mechanisms remain controversial. The activity of chloroplast ATP synthase (gH+) is usually depressed under high light when compared ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-020-00725-y
更新日期：2020-04-01 00:00:00
abstract：:Chlorosomes, the light-harvesting apparatus of green bacteria, are a unique antenna system, in which pigments are organized in aggregates rather than associated with proteins. Isolated chlorosomes from the green sulphur bacterium Chlorobium tepidum contain 10 surface-exposed proteins. Treatment of chlorosomes from Chl...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-005-3757-4
更新日期：2005-11-01 00:00:00
abstract：:We investigated several photosynthetic parameters of a virescent mutant of durum wheat and of its wild-type. Electron transport rate to ferricyanide was the same in the two genotypes when expressed on leaf area basis while O2 evolution of the leaf tissue in saturating light and CO2 was slightly higher in the yellow ge...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00033365
更新日期：1989-08-01 00:00:00
abstract：:The localization of isoprenoid lipids in chloroplasts, the accumulation of particular isoprenoids under high irradiance conditions, and channelling of photosynthetically fixed carbon into plastidic thylakoid isoprenoids, volatile isoprenoids, and cytosolic sterols are reviewed. During leaf and chloroplast development ...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-007-9204-y
更新日期：2007-05-01 00:00:00
abstract：:Bioenergetic properties of thylakoids from plants submitted to a water stress stress (watering stopped for 6-15 days) have been measured in two lupin genotypes characterized as resistant or susceptible to drought. This energy coupling was assessed by flow-force relationships relating the phosphorylation rate to the ma...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00035944
更新日期：1992-05-01 00:00:00
abstract：:With this Tribute, we remember and honor Thomas John (Tom) Wydrzynski. Tom was a highly innovative, independent and committed researcher, who had, early in his career, defined his life-long research goal. He was committed to understand how Photosystem II produces molecular oxygen from water, using the energy of sunlig...
journal_title：Photosynthesis research
pub_type： 传,历史文章,杂志文章
doi：10.1007/s11120-018-0606-9
更新日期：2019-06-01 00:00:00
abstract：:Minimal photosynthetic catalytic F1(αβ) core complexes, containing equimolar ratios of the α and β subunits, were isolated from membrane-bound spinach chloroplast CF1 and Rhodospirillum rubrum chromatophore RrF1. A CF1-α3β3 hexamer and RrF1-α1β1 dimer, which were purified from the respective F1(αβ) complexes, exhibit ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00020418
更新日期：1995-11-01 00:00:00
abstract：:Significance of molecular crowding in grana thylakoids of higher plants on photosystem II function was studied by 'titrating' the naturally high protein density by fusing unilamellar liposomes of the native lipid mixture with isolated grana membranes (BBY). The incorporation of lipids was monitored by equilibrium dens...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-007-9253-2
更新日期：2008-02-01 00:00:00
abstract：:An immunological method for quantitative determination of photosynthetic fructose-1,6-bisphosphatase in crude extracts of leaves is proposed. It is based on the ELISA technique, and offers two modifications. A non-competitive technique has a higher sensitivity and is the right option for samples of low fructose-1,6-bi...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00032710
更新日期：1987-01-01 00:00:00
abstract：:The linear, four-step oxidation of water to molecular oxygen by photosystem II requires cooperation between redox reactions driven by light and a set of redox reactions involving the S-states within the oxygen-evolving complex. The oxygenevolving complex is a highly ordered structure in which a number of polypeptides ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00037001
更新日期：1985-01-01 00:00:00
abstract：:Chlorobium tepidum is a Gram-negative bacterium of the green sulfur phylum (Chlorobia). Chlorobia are obligate anaerobic photolithoautotrophs that are widely distributed in aquatic environments where anoxic layers containing reduced sulfur compounds are exposed to light. The envelope of C. tepidum is a complex organel...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-010-9544-x
更新日期：2010-06-01 00:00:00
abstract：:The origin of the extraordinary high redox potential of P680, the primary electron donor of Photosystem II, is still unknown. Photochemically induced dynamic nuclear polarisation (photo-CIDNP) 13C magic-angle spinning (MAS) NMR is a powerful method to study primary electron donors. In order to reveal the electronic st...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-005-0411-0
更新日期：2005-06-01 00:00:00
