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1.
Rapid and simple isolation of pure photosystem II core and reaction center particles from spinach 总被引:2,自引:2,他引:0
Peter J. van Leeuwen Maaike C. Nieveen Erik Jan van de Meent Jan P. Dekker Hans J. van Gorkom 《Photosynthesis research》1991,28(3):149-153
Pure and active oxygen-evolving PS II core particles containing 35 Chl per reaction center were isolated with 75% yield from spinach PS II membrane fragments by incubation with n-dodecyl--D-maltoside and a rapid one step anion-exchange separation. By Triton X-100 treatment on the column these particles could be converted with 55% yield to pure and active PS II reaction center particles, which contained 6 Chl per reaction center.Abbreviations Bis-Tris
bis[2-hydroxyethyl]imino-tris[hydroxymethyl]methane
- Chl
chlorophyll
- CP29
Chl a/b protein of 29 kDa
- Cyt b
559
cytochrome b
559
- DCBQ
2,5-dichloro-p-benzo-quinone
- LHC II
light-harvesting complex II, predominant Chl a/b protein
- MES
2-[N-Morpholino]ethanesulfonic acid
- Pheo
pheophytin
- PS H
photosystem II
- QA
bound plastoquinone, serving as the secondary electron acceptor in PS II (after Pheo)
- SDS
sodiumdodecylsulfate 相似文献
2.
The Chl-protein complexes of three maize (Zea mays L.) mutants and one barley (Hordeum vulgare L.) mutant were analyzed using low temperature Chl fluorescence emissions spectroscopy and LDS-polyacrylamide gel electrophoresis. The maize mutants hcf-3, hcf-19, and hcf-114 all exhibited a high Chl fluorescence (hcf) phenotype indicating a disruption of the energy transfer within the photosynthetic apparatus. The mutations in each of these maize mutants affects Photosystem II. The barley mutant analyzed was the well characterized Chl b-less mutant chlorina-f2, which did not exhibit the hcf phenotype. Chlorina-f2 was used because no complete Chl b-less mutant of maize is available. Analysis of hcf-3, hcf-19, and hcf-114 revealed that in the absence of CP43, LHC II can still transfer excitation energy to CP47. These results suggest that in mutant membranes LHC II can interact with CP47 as well as CP43. This functional interaction of LHC II with CP47 may only occur in the absence of CP43, however, it is possible that LHC II is positioned in the thylakoid membranes in a manner which allows association with both CP43 and CP47.Abbreviations
hcf
high chlorophyll fluorescence
- LDS
lithium dodecyl sulfate
- LHC II
light-harvesting complex of Photosystem II
- LHC I
light-harvesting complex of Photosystem I
- CPIa
chlorophyll-protein complex consisting of LHC I and the PS I core complex
- CPI
chlorophyll-protein complex consisting of the PS I core complex
- CP47
47 kDa chlorophyll-protein of the Photosystem II core
- CP43
43 kDa chlorophyll-protein of the Photosystem II core
- CP29
29 kDa chlorophyll-protein of Photosystem II
- CP26
26 kDa chlorophyll-protein of Photosystem II
- CP24
24 kDa chlorophyll-protein of Photosystem II
- fp
free pigments 相似文献
3.
Chimaeric mutants of the cyanobacterium Synechocystis sp. PCC 6803 have been generated carrying part or all of the spinach psbB gene, encoding CP47 (one of the chlorophyll-binding core antenna proteins in Photosystem II). The mutant in which the entire psbB gene had been replaced by the homologous gene from spinach was an obligate photoheterotroph and lacked Photosystem II complexes in its thylakoid membranes. However, this strain could be transformed with plasmids carrying selected regions of Synechocystis psbB to give rise to photoautotrophs with a chimaeric spinach/cyanobacterial CP47 protein. This process involved heterologous recombination in the cyanobacterium between psbB sequences from spinach and Synechocystis 6803; which was found to be reasonably effective in Synechocystis. Also other approaches were used that can produce a broad spectrum of chimaeric mutants in a single experiment. Functional characterization of the chimaeric photoautotrophic mutants indicated that if a decrease in the photoautotrophic growth rates was observed, this was correlated with a decrease in the number of Photosystem II reaction centers (on a chlorophyll basis) in the thylakoid membrane and with a decrease in oxygen evolution rates. Remaining Photosystem II reaction centers in these chimaeric mutants appeared to function rather normally, but thermoluminescence and chlorophyll a fluorescence measurements provided evidence for a destabilization of QB
–. This illustrates the sensitivity of the functional properties of the PS II reaction center to mild perturbations in a neighboring protein.Abbreviations diuron
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- Fv
variable chlorophyll a fluorescence
- HEPES
N-(2-hydroxyethyl)piperazine-N-(2-ethanesulfonic acid)
- (k)bp
(kilo)base pairs
- PS II
Photosystem II
- QA
primary electron-accepting plastoquinone in Photosystem II
- QB
secondary electron-accepting plastoquinone in Photosystem II
- SDS
sodium dodecyl sulfate 相似文献
4.
The structure and heterogeneity of LHC II were studied by in vitro reconstitution of apoproteins with pigments (Plumley and Schmidt 1987, Proc Natl Acad Sci 84: 146–150). Reconstituted CP 2 complexes purified by LDS-PAGE were subsequently characterized and shown to have spectroscopic properties and pigment-protein compositions and stoichiometries similar to those of authentic complexes. Heterologous reconstitutions utilizing pigments and light-harvesting proteins from spinach, pea and Chlamydomonas reinhardtii reveal no evidence of specialized binding sites for the unique C. reinhardtii xanthophyll loroxanthin: lutein and loroxanthin are interchangeable for in vitro reconstitution. Proteins modified by the presence of a transit peptide, phosphorylation, or proteolytic removal of the NH2-terminus could be reconstituted. Evidence suggests that post-translational modification are not responsible for the presence of six electrophoretic variants of C. reinhardtii CP 2. Reconstitution is blocked by iodoacetamide pre-treatment of the apoproteins suggesting a role for cysteine in pigment ligation and/or proper folding of the pigment-protein complex. Finally, no effect of divalent cations on pigment reassembly could be detected.Abbreviations
cab
chlorophyll a/b-binding protein genes
- Chl
chlorophyll
- CP2
light-harvesting chlorophyll A+b-protein complex fractionated by mildly denaturing LDS-PAGE from Photosystem II in thylakoids
- CP 43 and CP 47
chlorophyll a-antenna complexes fractionated from Photosystem II in thylakoids by mildly denaturing LDS-PAGE at 4°C
- IgG
gamma immunoglobulin
- LDS
lithium dodecyl sulfate
- LDS-PAGE
lithium dodecyl sulfate polyacrylamide gel electrophoresis at 4°C
- LHC I and LHC II
thylakoid light-harvesting chlorophyll a+b-protein holocomplexes associated with Photosystems I and II, respectively
- PS II
Photosystem II
- TX100
Triton X-100
- TX100-derived LHC
light-harvesting complexes enriched in LHC II following fractionation of thylakoids by TX100 相似文献
5.
Eva Šetlíková Stephan Ritter Rainer Hienerwadel Jiří Kopecký Josef Komenda Wolfram Welte Ivan Šetlík 《Photosynthesis research》1995,43(3):201-211
Oxygen-evolving PS II particles from the thermophilic cyanobacterium Synechococcus elongatus are partially purified by centrifugation on a sucrose gradient and are bound to a Chelating Sepharose column loaded with Cu2+ ions. Bound particles are then transformed into PS II RC complexes by two washing steps. First, washing with a phosphate buffer (pH=6.5) containing 0.02% of SB 12 removes the rest of phycobilins and leaves pure PS II core particles on the column. Second, washing with a phosphate buffer (pH=6.2) containing 0.2 M LiClO4 and 0.05% of DM removes CP 47 and CP 43 and leaves bare PS II RC complexes on the column. These are then eluted with a phosphate buffer containing 1% of dodecylmaltoside (DM). The molar ratio of pigments in the eluate changes with the progress of elution but around the middle of the elution period a nearly stable ratio is maintained of Chl a: Pheo a: Car: Cyt b 559 equal to 2.9: 1: 0.9: 0.8. In these fractions the photochemical separation of charges could be demonstrated by accumulation of reduced pheophytin (A of 430–440 nm) and by the flash induced formation of P680+ (A at 820 nm). The relatively slow relaxation kinetics of the latter signal (t1/2 1 ms) may suggest that in a substantial fraction of the RCs QA remains bound to the complex.Abbreviations Car
-carotene
- Chl a
chlorophyll a
- CP43, CP47
chlorophyll-proteins, with Rm 43 and 47 kDa
- DBMIB
dibromothymoquinone,2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone
- DM
-dodecyl-d-maltoside
- HPLC
high-performance liquid chromatography
- OG
n-octyl--d-glucopyranoside
- IMAC
immobilied metal affinity chromatography
- Pheo a
pheophytin a
- PQ-9
plastoquinone-9
- P680
primary electron donor in PS II
- PS II RC
Photosystem II reaction centre
- QA
primary electron acceptor in PS II
- SB-12
N-dodecyl-N,N-dimethyl-3-amino-1-propanesulphonate, (sulphobetain 12) 相似文献
6.
A highly purified oxygen evolving Photosystem II core complex was isolated from PS II membranes solubilized with the non-ionic detergent n-octyl--D-thioglucoside. The three extrinsic proteins (33, 23 and 17 kDa) were functionally bound to the PS II core complex. Selective extraction of the 22, 10 kDa, CP 26 and CP 29 proteins demonstrated that these species are not involved in the binding of the extrinsic proteins (33, 23 and 17 kDa) or the DCMU sensitivity of the Photosystem II complex.Abbreviations Chl
chlorophyll
- DCBQ
2,6-dichloro-p-benzoquinone
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- LHC
light-harvesting complex
- MES
2-(N-morpholino)ethanesulfonic acid
- OGP
n-octyl--d-glucoside
- OTG
n-octyl--d-thioglucoside
- PAGE
polyacrylamide gel electrophoresis
- PS II
Photosystem II
- SDS
sodium dodecyl sulfate 相似文献
7.
Stefan Falk Guy Samson Doug Bruce Norman P. A. Huner David E. Laudenbach 《Photosynthesis research》1995,45(1):51-60
Under conditions of iron-stress, the Photosystem II associated chlorophyll a protein complex designated CP 43, which is encoded by the isiA gene, becomes the major pigment-protein complex in Synechococcus sp. PCC 7942. The isiB gene, which is located immediately downstream of isiA, encodes the protein flavodoxin, which can functionally replace ferredoxin under conditions of iron stress. We have constructed two cyanobacterial insertion mutants which are lacking (i) the CP 43 apoprotein (designated isiA
–) and (ii) flavodoxin (designated isiB
–). The function of CP 43 was studied by comparing the cell characteristics, PS II functional absorption cross-sections and Chl a fluorescence parameters from the wild-type, isiA
– and isiB
– strains grown under iron-stressed conditions. In all strains grown under iron deprivation, the cell number doubling time was maintained despite marked changes in pigment composition and other cell characteristics. This indicates that iron-starved cells remained viable and that their altered phenotype suggests an adequate acclimation to low iron even in absence of CP 43 and/or flavodoxin. Under both iron conditions, no differences were detected between the three strains in the functional absorption crossection of PS II determined from single turnover flash saturation curves of Chl a fluorescence. This demonstrates that CP 43 is not part of the functional light-harvesting antenna for PS II. In the wild-type and the isiB
– strain grown under iron-deficient conditions, CP 43 was present in the thylakoid membrane as an uncoupled Chl-protein complex. This was indicated by (1) an increase of the yield of prompt Chl a fluorescence (Fo) and (2) the persistence after PS II trap closure of a fast fluorescence decay component showing a maximum at 685 nm.Abbreviations Chl
chlorophyll
- CP 43, CP 47 and CP 43
Chl a binding protein complexes of indicated molecular mass
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- Fm and Fm
fluorescence when all PS II reaction centers are dosed in dark- and light-acclimated cells, respectively
- Fo
fluorescence when all PS II reaction centers are open in dark acclimated cells
- Fv
variable fluorescence after dark acclimation (Fm–Fo) 相似文献
8.
LHC II isolated from carnation leaves has been solubilized and resolved by a newly developed, vertical-bed non-denaturing isoelectric focusing in polyacrylamide slab gels to yield three trimeric subcomplexes focusing at pH 4.52, 4.42 and 4.37 (designated a, b and c, respectively), comprising approximately 38%, 24% and 38% of the chlorophyll. The spectroscopic data demonstrated a close similarity among LHC II subcomplexes concerning their chlorophyll content and organization. The most alkaline and the most acidic subcomplex contained the 27 kDa polypeptide of LHC II while the intermediate pI fraction contained both LHC II polypeptides, i.e. 27 kDa and 26 kDa ones associated at 2:1 stoichiometry. The 27 kDa polypeptide could be resolved by denaturing isoelectrofocusing into 10 pI molecular isoforms covering 5.90–4.20 pH range. Three of the isoforms were found in the subcomplexes a and b and eight in the subcomplex c. The 26 kDa polypeptide comprised the unique pI molecular isoform focusing at pH 5.61.Abbreviations CBB G-250
Coomassie Brilliant Blue G-250
- chl
chlorophyll
- DM
n-dodecyl--d-maltoside
- EDTA
ethylendiaminotetraacetic acid
- IEF
isoelectric focusing
- LHC II
the main light-harvesting chlorophyll a/b-protein complex of Photosystem II
- LHCP II
apoprotein of the main light-harvesting chlorophyll a/b-protein complex of Photosystem II
- NP-40
polyethyleneglycol-p-isooctylphenyl ether
- pI
isoelectric point
- OG
octyl--d-glucopyranoside
- PS II
Photosystem II
- SDS-PAGE
sodium dodecylsulphate polyacrylamide gel electrophoresis
- TCA
trichlorooacetic acid 相似文献
9.
Maria Rova Lars-Gunnar Franzén Per-Olof Fredriksson Stenbjörn Styring 《Photosynthesis research》1994,39(1):75-83
The psbP gene product, the so called 23 kDa extrinsic protein, is involved in water oxidation carried out by Photosystem II. However, the protein is not absolutely required for water oxidation. Here we have studied Photosystem II mediated electron transfer in a mutant of Chlamydomonas reinhardtii, the FUD 39 mutant, that lacks the psbP protein. When grown in dim light the Photosystem II content in thylakoid membranes of FUD 39 is approximately similar to that in the wild-type. The oxygen evolution is dependent on the presence of chloride as a cofactor, which activates the water oxidation with a dissociation constant of about 4 mM. In the mutant, the oxygen evolution is very sensitive to photoinhibition when assayed at low chloride concentrations while chloride protects against photoinhibition with a dissociation constant of about 5 mM. The photoinhibition is irreversible as oxygen evolution cannot be restored by the addition of chloride to inhibited samples. In addition the inhibition seems to be targeted primarily to the Mn-cluster in Photosystem II as the electron transfer through the remaining part of Photosystem II is photoinhibited with slower kinetics. Thus, this mutant provides an experimental system in which effects of photoinhibition induced by lesions at the donor side of Photosystem II can be studied in vivo.Abbreviations Chl
chlorophyll
- DCIP
2,6-dichlorophenolindophenol
- DPC
2,2-diphenylcarbonic dihydrazide
- HEPES
4-(2-hydroxyethyl)-1-piperazinethanesulfonic acid
- P680
the primary electron donor to PS II
- PpBQ
phenyl-p-benzoquinone
- PS II
Photosystem II
- QA
the first quinone acceptor of PS II
- QB
the second quinone acceptor of PS II
- SDS
sodium dodecyl sulfate
- Tris
tris(hydroxymethyl)aminomethane
- TyrD
accessory electron donor on the D2-protein
- TyrZ
tyrosine residue, acting as electron carrier between P680 and the water oxidizing system 相似文献
10.
Kiriakos Kotzabasis Constantina Fotinou Kalliopi A. Roubelakis-Angelakis Demetrios Ghanotakis 《Photosynthesis research》1993,38(1):83-88
The three main polyamines putrescine (Put), spermidine (Spd) and spermine (Spm) were characterized by HPLC in intact spinach leaf cells, intact chloroplasts, thylakoid membranes, Photosystem II membranes, the light-harvesting complex and the PS II complex. All contain the three polyamines in various ratios; the HPLC polyamine profiles of highly resolved PS II species (a Photosystem II core and the rection center) suggest an enrichment in the polyamine Spm.Abbreviations Chl
chlorophyll
- HPLC
high performance liquid chromatography
- LHC
light-harvesting complex
- PS II
Photosystem II
- PS II-RC
Photosystem II reaction center
- Put
putrescine
- Spd
spermidine
- Spm
spermine
- 10%S-core
D1-D2-Cyt b559-47 kD-43 kD complex 相似文献
11.
Photosystem II (PS II) reactions of chloroplast particles show the same variations during the synchronous life cycle of Scenedesmus obliquus, strain D3 (Gaffron Biol. Zbl. 59, 302 1939), as the whole cells they derived from. Photosystem I (PS I) reactions of whole cells and of subchloroplast particles show little or no variation in their activity, whereas PS I reactions of chloroplast particles vary like PS II reactions during the life cycle. The variation in chloroplast particles could be attributed to the change in the reoxidation capacity of plastoquinone still attached to PS I. Digitonin-treatment of chloroplast particles from Scenedesmus and subsequent sucrose density gradient separation yielded 3 distinct fractions: Fraction I contained pure PS I particles with the most efficient PS I-mediated methylviologen (MV) reduction with subsequent oxygen uptake (3 mmol O2/mg Chl·h); no Hill reaction; and a high chlorophyll a/b ratio, and a vast amount of unbound protein xanthophyll complexes. Fraction II is enriched in PS II particles, with little PS I activity (less than 10% of the PS I particles) and a low chlorophyll a/b ratio. The activity of the water-splitting system was completely lost. This fraction must also contain most of the light-harvesting pigment system. Fraction III is also enriched in PS II with even less PS I activity, but the ratio of chlorophyll a/b is slightly higher than in whole cells and the water-splitting system is intact. -carotene was part of all fractions whereas functional xanthophylls seemed to be restricted to the PS II particles. From the constant chlorophyll P/700 ratio we had to conclude that size of the photosynthetic unit does not change during the life cycle of a synchronized Scenedesmus obliquus culture.Abbreviations DBMIB
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethyl-urea
- DCPIP
dichlorphenolindophenol
- MV
methylviologen (paraquat)
- PS I
photosystem I
- PS II
photosystem II
- DPC
diphenyl-carbazide 相似文献
12.
Reelectrophoresis of the oligomer form (CP II1) of the chlorophyll light-harvesting complex (LHC) from the green alga Acetabularia yields two green bands which run at the position typical of the monomer (CP II). The upper green band (CP II1) is enriched in the 27 kDa polypeptide of the LHC, while the lower is enriched in the 26 kDa polypeptide. The fact that both bands have both chlorophyll (Chl) a and b, and in the same ratio, implies that the LHC is made up of two Chl proteins. Neither of these bands can be attributed to the Chl complex ‘CP 29’ (Camm, E.L. and Green, B.R. (1980) Plant Physiol. 66, 428–432). Resolution of CP II1 and CP II2 of spinach can be obtained if sucrose gradient fractions of an octylglucoside extract are subjected to SDS-polyacrylamide gel electrophoresis. CP II1 and CP II2 are interpreted as being fundamental subunits of the light-harvesting complex as it is defined on SDS-polyacrylamide gels. 相似文献
13.
Synechocystis sp. PCC 6803 when grown in the presence of sublethal (M) levels of cobalt chloride shows an enhancement of Photosystem II (PS II) catalyzed Hill reaction. This stimulation seems to be induced by cobalt ions as other metal ions inhibit para-benzoquinone catalyzed Hill reaction. At saturating white light intensity, this enhancement is two times over that of the control cells on unit chlorophyll basis. Analysis of the PS II electron transport rate at varying intensities of white, blue or yellow light suggests an increased maximal rates but no change in the quantum yield or effective antenna size of CoCl2-grown cells. There were no structural and functional changes in the phycobilisome as judged by the absence of changes in the phycocyanin/allophycocyanin ratio, fluorescence emission spectra, second derivative absorption spectra at 77 K and SDS-PAGE analysis of isolated phycobilisomes. The 77 K fluorescence emission spectra of the cells showed a decrease in the ratio of Photosystem I emission (F725) to Photosystem II emission (F685) in CoCl2-grown cells compared to the control cells. These observations indicate three possibilities: (1) there is an increase in the number of Photosystem II units; (2) a faster turnover of Photosystem II centers; or (3) an alteration in energy redistribution between PS II and PS I in CoCl2-grown cells which causes stimulation of Photosystem II electron transport rate.Abbreviations APC
allophycocyanin
- Chl a
chlorophyll a
- DBMIB
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone
- EDTA
ethylene diamine tetraacetic acid
- PBS
phycobilisome
- PC
phycocyanin
- PSI
Photosystem I
- PS II
Photosystem II
- pBQ
p-benzoquinone
- PMSF
phenyl methyl sulfonyl fluoride 相似文献
14.
Tanya G. Falbel L. Andrew Staehelin William W. Adams III 《Photosynthesis research》1994,42(3):191-202
Three light intensity-dependent Chl b-deficient mutants, two in wheat and one in barley, were analyzed for their xanthophyll cycle carotenoids and Chl fluorescence characteristics under two different growth PFDs (30 versus 600 mol photons·m–2 s–1 incident light). Mutants grown under low light possessed lower levels of total Chls and carotenoids per unit leaf area compared to wild type plants, but the relative proportions of the two did not vary markedly between strains. In contrast, mutants grown under high light had much lower levels of Chl, leading to markedly greater carotenoid to Chl ratios in the mutants when compared to wild type. Under low light conditions the carotenoids of the xanthophyll cycle comprised approximately 15% of the total carotenoids in all strains; under high light the xanthophyll cycle pool increased to over 30% of the total carotenoids in wild type plants and to over 50% of the total carotenoids in the three mutant strains. Whereas the xanthophyll cycle remained fairly epoxidized in all plants grown under low light, plants grown under high light exhibited a considerable degree of conversion of the xanthophyll cycle into antheraxanthin and zeaxanthin during the diurnal cycle, with almost complete conversion (over 90%) occurring only in the mutants. 50 to 95% of the xanthophyll cycle was retained as antheraxanthin and zeaxanthin overnight in these mutants which also exhibited sustained depressions in PS II photochemical efficiency (Fv/Fm), which may have resulted from a sustained high level of photoprotective energy dissipation activity. The relatively larger xanthophyll cycle pool in the Chl b-deficient mutant could result in part from the reported concentration of the xanthophyll cycle in the inner antenna complexes, given that the Chl b-deficient mutants are deficient in the peripheral LHC-II complexes.Abbreviations A
antheraxanthin
- Chl
chlorophyll
- Fo and Fm
minimal yield (at open PS II reaction centers) and maximal yield (at closed centers) of chlorophyll fluorescence in darkness
- F
level of fluorescence during illumination with photosynthetically active radiation
- Fm
maximal yield (at closed centers) of chlorophyll fluorescence during illumination with photosynthetically active radiation
- (Fm–F)/Fm
actual efficiency of PS II during illumination with photosynthetically active radiation
- Fv/Fm+(Fm–Fo)/Fm
intrinsic efficiency of PS II in darkness
- LHC_II
light-harvesting chlorophyll-protein complex of Photosystem II
- PFD
photon flux density (between 400 and 700 nm)
- PS I
Photosystem I
- PS II
Photosystem II
- V
violaxanthin
- Z
zeaxanthin 相似文献
15.
Tim D. Davis 《Photosynthesis research》1987,14(3):201-209
Photosystem II particles from spinach and barley contained 2.5 and 4.2 Cu per 300 chlorophylls respectively. This Cu was resistant to removal by EDTA. A large percentage of the PSII Cu in both plants is associated with the light-harvesting chlorophyll a/b protein, LHCII; 46% in barley and 76% in spinach. Several experiments have been performed to rule out the possibility that the Cu was introduced during the isolation procedures and to ensure that the Cu is associated with PSII. Since the PSII Cu is mainly associated with LHCII, it is unlikely that it is involved in O2 evolution.Abbreviations BBY
PSII particles prepared as in [4] with modifications
- LHCII
Light Harvesting Chlorophyll a/b protein
- MMN
50mM Mes-NaOH, 5 mM MgCl2, 15 mM NaCl
- SOD
Superoxide Dismutase
- TEMED
N,N,N,N-tetramethylethylenediamine
Some of the results in this paper appeared in preliminary form in the Proceedings of the VIIth International Congress on Photosynthesis [24]. 相似文献
16.
Hidenori Hayashi Yoko Fujimura Prasanna S. Mohanty Norio Murata 《Photosynthesis research》1993,36(1):35-42
In order to identify the domain within Photosystem II complexes that functions in the evolution of oxygen, we performed limited proteolysis with lysylendopeptidase of the core complex of Photosystem II which had been depleted of the extrinsic 33-kDa protein (Mn-stabilizing protein). The cleavage sites were estimated from the amino-terminal sequences of the degradation fragments, their apparent molecular masses and amino-acid compositions. Under certain conditions, the D2 protein was cleaved at Lys13; and a chlorophyll a-binding protein, CP 47, was cleaved at Lys227 and Lys389. Another chlorophyll a-binding protein, CP 43, was degraded more rapidly than CP 47. The oxygen-evolving activity and the capacity for rebinding of the 33-kDa protein to the core complex of Photosystem II decreased in parallel, with kinetics very similar to those of the cleavage of CP 47 at Lys389. These observations strongly suggest that the hydrophilic domain around Lys389 of CP 47, which are located on the lumenal side, is important in the binding of the 33-kDa protein and in maintaining the oxygen-evolving activity of the Photosystem II complex.Abbreviations CP 47 and CP 43-
intrinsic chlorophyll a-binding proteins with apparent molecular masses of 47 and 43 kDa, respectively
- PBQ-
phenyl-p-benzoquinone
- TLCK-
N--p-tosyl-L-lysine chloromethyl ketone 相似文献
17.
An improved, non-detergent, method for preparative isolation of PS II membrane vesicles from spinach chloroplasts is presented. Thylakoids (chlorophyll (Chl) a/b ratio 2.8, Chl/P700 435) were fractionated by Yeda press treatment and aqueous two-phase partition to yield inside-out vesicles (1) (chl a/b 2.2, chl/P700 700). These vesicles were subjected a sonication — phase partitioning procedure; steps of sonication of inside-out vesicles, while still present in a dextran-polyethylene glycol two-phase system were alternated by phase partition. These steps selectively removed P700-containing membrane fragments from the inside-out vesicles and yielded a membrane fraction with improved PS II purity (Chl a/b ratio 1.9, Chl/P700 1500) and retained oxygen evolving capacity (295 mol O2 mg Chl-1 h-1). 相似文献
18.
Svetlana M. Kochubey Victor V. Shevchenko Olga I. Volovik 《Photosynthesis research》1993,38(2):153-157
Chloroplast proteins were phosphorylated under two test conditions: white light irradiance alone and white light irradiance with the addition of glucose and glucose oxidase, used to produce an anaerobic medium. The interaction of phospho-LHC II with Photosystem 1 (PS 1) was studied for two types of PS I preparation. Changes in the chlorophyll a/b ratio and the ratio of 650 and 680 nm band intensities (E650/E680) in fluorescence excitation spectra were used in calculating the phospho-LHC II portion which became associated with PS 1. It is shown that the associated portion of phospho-LHC II varies for each of the PS 1 preparations and phosphorylation procedures. Possible conclusions as regards the transfer of various sets of LHC II subpopulations under different phosphorylation procedures and the differences of interaction with PS 1 are discussed.Abbreviations PS 1
Photosystem 1
- PS 2
Photosystem 2
- LHC II
light-harvesting chlorophyll a/b protein complex II
- Chl
chlorophyll
-
fluorescence quantum yield
- f
life time of fluorescence at =685 nm
- F735
fluorescence band with a maximum at 735 nm
- F685
fluorescence band with a maximum at 685 nm
- E650/E680
ratio of amplitudes in excitation fluorescence spectrum at 650 and 680 nm 相似文献
19.
Phosphatase activities in spinach thylakoid membranes-effectors, regulation and location 总被引:1,自引:0,他引:1
The dephosphorylation of seven phosphoproteins associated with Photosystem II or its chlorophyll a/b antenna in spinach thylakoids, was characterised. The rates were found to fall into two distinct groups. One, rapidly dephosphorylated, consisted of the two subunits (25 and 27 kD) of the major light harvesting complex of Photosystem II (LHC II) and a 12 kD polypeptide of unknown identity. A marked correlation between the dephosphorylation of these three phosphoproteins, strongly suggested that they were all dephosphorylated by the same enzyme. Within this group, the 25 kD subunit was consistently dephosphorylated most rapidly, probably reflecting its exclusive location in the peripheral pool of LHC II. The other group, only slowly dephosphorylated, included several PS II proteins such as the D1 and D2 reaction centre proteins, the chlorophyll-a binding protein CP43 and the 9 kD PS II-H phosphoprotein. No dephosphorylation was observed in either of the two groups in the absence of Mg2+-ions. Dephosphorylation of the two LHC II subunits took place in both grana and stroma-exposed regions of the thylakoid membrane. However, deposphorylation in the latter region was significantly more rapid, indicating a preferential dephosphorylation of the peripheral (or mobile) LHC II. Dephosphorylation of LHC II was found to be markedly affected by the redox state of thiol-groups, which may suggest a possible regulation of LHC II dephosphorylation involving the ferredoxin-thioredoxin system.Abbreviations CP 43
43 kD chlorophyll a- binding protein
- D1 and D2
reaction centre proteins of PS II
- LHC II
light-harvesting complex of PS II
- LHC II-25
25 kD subunit of LHC II
- LHC II-27
27 kD subunit of LHC II
- NEM
N-ethylmaleimide
- PP2C
protein phosphatase 2C
- PS II-H
psb H gene product 相似文献
20.
Formation of thermoluminescence signals is characteristics of energy- and charge storage in Photosystem II. In isolated D1/D2/cytochrome b-559 Photosystem II reaction centre preparation four thermoluminescence components were found. These appear at -180 (Z band), between -80 and -50 (Zv band), at -30 and at +35°C. The Z band arises from pigment molecules but not correlated with photosynthetic activity. The Zv and -30°C bands arise from the recombination of charge pairs stabilized in the Photosystem II reaction centre complex. The +35°C band probably corresponds to the artefact glow peak resulting from a pigment-protein-detergent interaction in subchloroplast preparations (Rózsa Zs, Droppa M and Horváth G (1989) Biochim Biophys Acta 973, 350–353).Abbreviations Chl
chlorophyll
- Cyt
cytochrome
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- D1
psbA gene product
- D2
psbD gene product
- P680
primary electron donor of PS II
- Pheo
pheophytin
- PS II
Photosystem II
- QA
primary quinone acceptor of PS II
- QB
secondary quinone acceptor of PS II
- RC
reaction centre of PS II
- TL
thermoluminescence 相似文献