Abstract：
:The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase fromEuglena gracilis decays steadily when exposed to agents that induce oxidative modification of cysteine residues (Cu(2+), benzofuroxan, disulfides, arsenite, oxidized ascorbate). Inactivation takes place with a concomitant loss of cysteine sulfhydryl groups and dimerization of large subunits of the enzyme. 40% activity loss induced by the vicinal thiol-reagent arsenite is caused by modification of a few neighbor residues while the almost complete inactivation achieved with disulfides is due to extensive oxidation leading to formation of mixed disulfides with critical cysteines of the protein. In most cases oxidative inactivation is also accompanied by an increased sensitivity to proteolysis by trypsin, chymotrypsin or proteinase K. Both enzymatic activity and resistance to proteolysis can be restored through treatment with several thiols (cysteamine, cysteine, dithiothreitol and, more slowly, reduced glutathione). Redox effectors which are thought to regulate the chloroplast activity (NADPH, ferredoxin and thioredoxin) do not reactivate the oxidized enzyme. When ribulose-1,5-bisphoshate carboxylase/oxygenase is incubated with cystamine/cysteamine mixtures having different disulfide/thiol ratio (r), inactivation takes place around r=1.5 while proteolytic sensitization occurs under more oxidative conditions (r=4). It is suggested that oxidative modification may happen in vivo under exceptional circumstances, such as senescence, bleaching or different kinds of stress, leading to enzyme inactivation and triggering the selective degradation of the carboxylase that has been repeatedly observed during these processes.
journal_name
Photosynth Resjournal_title
Photosynthesis researchauthors
García-Ferris C,Moreno Jdoi
10.1007/BF02185411subject
Has Abstractpub_date
1993-01-01 00:00:00pages
55-66issue
1eissn
0166-8595issn
1573-5079journal_volume
35pub_type
杂志文章abstract：:The excitation energy transfer between carotenoid and chlorophyll (Chl) in the cytochrome b ( 6 ) f complex from Bryopsis corticulans (B. corticulans), in which the carotenoid is 9-cis-alpha-carotene, was investigated by means of fluorescence excitation and sub-microsecond time-resolved absorption spectroscopies. The ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-005-9020-1
更新日期：2006-04-01 00:00:00
abstract：:Recently, a number of techniques, some of them relatively new and many often used in combination, have given a clearer picture of the dynamic role of electron transport in Photosystem I of photosynthesis and of coupled cyclic photophosphorylation. For example, the photoacoustic technique has detected cyclic electron t...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00033035
更新日期：1993-06-01 00:00:00
abstract：:The chlorophyll content is an important experimental parameter in agronomy and plant biology research. In this report, we explore the feasibility of determining total concentration of extracts containing chlorophyll a and chlorophyll b by chlorophyll fluorescence. We found that an excitation at 457 nm results in the s...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-012-9777-y
更新日期：2012-10-01 00:00:00
abstract：:Phosphoenolpyruvate carboxylase from leaves of the C4 plant Setaria verticillata (L.) Beauv. is activated by light; day levels of activity are reached after 30 minutes of illumination. Photoactivation is prevented by inhibitors of photosynthetic electron flow or of photophosphorylation and by D,L-glyceraldehyde, which...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00028842
更新日期：1988-06-01 00:00:00
abstract：:Artificial aggregates of bacteriochlorophyllc (BChlc) were formed in an aqueous medium in the presence of a lipid, monogalactosyl diglyceride (MGDG), and the optical properties of those aggregates were studied by absorption and circular dichroism (CD) mainly. Four BChlc homologs, ([E,E]BChlc F, [P,E]BChlc F, [E,M]BChl...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF02184164
更新日期：1994-07-01 00:00:00
abstract：:Exposure of the red alga Porphyra perforata or leaves of Phytolacca americana and Echinodorus sp. to white light equivalent to full sunlight for short periods induced large decreases of variable fluorescence measured at 695 nm at 77K. This change was not produced by photoinhibition but rather appeared to result from a...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00118298
更新日期：1986-01-01 00:00:00
abstract：:Soybean [Glycine max (L.) Merr. cv. Williams 82 and A3127] plants were grown in the field under long-term soil moisture deficit and irrigation to determine the effects of severe drought stress on the photosynthetic capacity of soybean leaves. Afternoon leaf water potentials, stomatal conductances, intercellular CO2 co...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00051735
更新日期：1990-07-01 00:00:00
abstract：:Oxygen may enhance CO2-saturated photosynthesis in intact leaves, which display the Warburg effect when illuminated at the current atmospheric level of CO2 and O2, of about 350 microl l(-1) and 21%, respectively. The magnitude of the stimulation depends on irradiance. The K(M)(O2) of the stimulation is 128 microM (10....
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-006-9050-3
更新日期：2006-06-01 00:00:00
abstract：:Marine macroalgae possess a range of mechanisms to increase the availability of CO2 for fixation by ribulose-1,5-bisphosphate carboxylase/oxygenase. Of these, possession of a periplasmic or external carbonic anhydrase and the ability to use bicarbonate ions is widely distributed. The mechanisms of carbon acquisition w...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-014-0003-y
更新日期：2014-09-01 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 detailed analysis of the periplasmic electron carriers of the photosynthetic bacterium Ectothiorhodospira sp. has been performed. Two low mid-point redox potential electron carriers, cytochrome c' and cytochrome c, are detected. A high potential iron-sulfur protein is the only high mid-point redox potential electron...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1023/A:1006486307473
更新日期：2000-01-01 00:00:00
abstract：:A protocol for the isolation of functional thylakoids from Arabidopsis thaliana leaves was developed. The critical factor in obtaining active, coupled and stable preparation is the inclusion of EDTA and EGTA in the grinding buffer. Preparations were characterized with respect to the whole or partial electron transport...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1023/A:1011818021875
更新日期：2001-01-01 00:00:00
abstract：:A comparative study of photosystem II complexes isolated from tobacco (Nicotiana tabacum L. cv. John William's Broadleaf) which contains normal stacked thylakoid membranes, and from two chlorophyll deficient tobacco mutants (Su/su and Su/su var. Aurea) which have low stacked grana or essentially unstacked thylakoids w...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00032264
更新日期：1987-01-01 00:00:00
abstract：:Little is known about the mechanistic basis for the movement of promiscuous nucleic acids across cell membranes. To address this problem we sought conditions that would permit the entry of plasmid DNA into isolated, intact pea chloroplasts. DNA uptake did not occur normally, but was induced by hypotonic treatments, by...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00020448
更新日期：1995-11-01 00:00:00
abstract：:This minireview summarizes the current state of knowledge concerning the role of Cl(-) in the oxygen-evolving complex (OEC) of photosystem II (PSII). The model that proposes that Cl(-) is a Mn ligand is discussed in light of more recent work. Studies of Cl(-) specificity, stoichiometry, kinetics, and retention by extr...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-006-9121-5
更新日期：2007-07-01 00:00:00
abstract：:A proton electrochemical potential across the membranes of photosynthetic purple bacteria is established by a light-driven proton pump mechanism: the absorbed light in the reaction center initiates electron transfer which is coupled to the vectorial displacement of protons from the cytoplasm to the periplasm. The stoi...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF02185435
更新日期：1993-07-01 00:00:00
abstract：:Two-component regulatory systems that respond to changes in redox potential have recently been discovered in bacteria. 'Redox sensors' are defined as electron carriers which initiate control of gene expression upon oxidation or reduction. 'Redox response regulators' are defined as DNA-binding proteins which modify gen...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00016274
更新日期：1993-05-01 00:00:00
abstract：:Isolated mesophyll cells from darkened leaves of the C(4) plant Digitaria sanguinalis keep functional plasmodesmata that allow the free exchange of low molecular mass compounds with the surrounding medium. This cell suspension system has been used to measure C(4) PEPC activity in situ using a spectrophotometric assay....
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1023/B:PRES.0000017179.31351.f0
更新日期：2004-01-01 00:00:00
abstract：:The xanthophyll cycle represents one of the important photoprotection mechanisms in plant cells. In the present review, we summarize current knowledge about the violaxanthin cycle of vascular plants, green and brown algae, and the diadinoxanthin cycle of the algal classes Bacillariophyceae, Xanthophyceae, Haptophyceae...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-010-9536-x
更新日期：2010-11-01 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：:Electron transfer pathways in photosynthesis involve interactions between membrane-bound complexes such as reaction centres with an extrinsic partner. In this study, the biological specificity of electron transfer between the reaction centre-light-harvesting 1-PufX complex and its extrinsic electron donor, cytochrome ...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-013-9812-7
更新日期：2014-05-01 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：:Historically, two main concepts guided research into possible mechanisms of light-induced atomic rearrangements in oxygenic photosynthesis: Photodecomposition of CO2 and photodecomposition of water. Both concepts envisioned photoinduced transfers of cumbersome whole atoms and not, as is currently held, photoinduced el...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00036216
更新日期：1991-09-01 00:00:00
abstract：:The biogenesis and oxygen-evolving activity of cyanobacterial Photosystem II (PSII) is dependent on a number of accessory proteins not found in the crystallised dimeric complex. These include Psb27, a small lipoprotein attached to the lumenal side of PSII, which has been assigned a role in regulating the assembly of t...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/s11120-011-9712-7
更新日期：2012-02-01 00:00:00
abstract：:This review focuses on our recent efforts in synthetic ruthenium-tyrosine-manganese chemistry mimicking the donor side reactions of Photosystem II. Tyrosine and tryptophan residues were linked to ruthenium photosensitizers, which resulted in model complexes for proton-coupled electron transfer from amino acids. A new ...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-005-9005-0
更新日期：2006-01-01 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：:The Mg-dechelating activity of extracts of Chenopodium album (goosefoot) was investigated using an artificial substrate, chlorophyllin a. The activity was measured spectrophotometrically by the formation of a reaction product, pheophorbin a (Mg-free chlorin), after release of the central Mg. The Mg-releasing protein w...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1023/A:1020915812770
更新日期：2002-01-01 00:00:00
abstract：:The dependence of chlorosome development on bacteriochlorophyll (BChl)c synthesis was studied with the phototrophic green bacteriumChloroflexus aurantiacus. By selecting defined culture conditions, three possibilities could be identified. Upon addition of 5-aminolevulinic acid, cells of resting cultures increased thei...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF02184154
更新日期：1994-07-01 00:00:00
abstract：:The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel usin...
journal_title：Photosynthesis research
pub_type： 杂志文章,评审
doi：10.1007/s11120-013-9828-z
更新日期：2013-11-01 00:00:00
abstract：:The factors governing quinone protein binding in the photosynthetic bacterium Rps. viridis are investigated via use of empirical intermolecular energy calculations using the GRID method (PJ Goodford (1985) J Med Chem 28: 849-854). A probe atom corresponding to a carbonyl oxygen atom is used to investigate regions exhi...
journal_title：Photosynthesis research
pub_type： 杂志文章
doi：10.1007/BF00027142
更新日期：1994-01-01 00:00:00
