检索结果-内蒙古大学图书馆

CYANOBACTERIAL AND CHLOROPLAST f1-ATPASES - CROSS-RECONSTITUTION Of PHOTOPHOSPHORYLATION AND SUBUNIT IMMUNOLOGICAL RELATIONSHIPS

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第2期851卷 217-222页

作者： HICKS, DB NELSON, N YOCUM, Cf UNIV MICHIGAN DEPT BIOL ANN ARBOR MI 48109 USA ROCHE INST MOLEC BIOL DEPT BIOCHEM NUTLEY NJ 07110 USA

The photosynthetic f1-ATPase from the cyanobacterium Spirulina platensis was recently purified in a five-subunit, reconstitutively active form (Hicks, D. B. and Yocum, C. f. (1986) Arch. Biochem. Biophys, 245, 220-229). Here we report on the similarities of the cyanobacterial f1 to the higher plant chloroplast f1 (Cf1), as judged by two distinct methods. The ability of each coupling factor to reconstitute photophosphorylation in photosynthetic membranes depleted of f1 content by 2 M NaBr treatment was tested. Addition of either the homologous enzyme (e.g., Spirulina f1, Spirulina membranes) or the heterologous enzyme (e.g., spinach Cf1 Spirulina membranes) to depleted membranes increased the rate of phenazine methosulfate-dependent cyclic photophosphorylation from nearly zero to up to 70 .*** ATP/h per mg Chl. Antibodies against four subunits of Cf1 (.alpha., .gamma., .delta. and .epsilon.) and against .beta. of Escherichia coli f1 were reacted with the Spirulina enzyme by protein blotting. The .alpha., .beta. and .gamma. subunits of Spirulina f1 cross-reacted with antibodies against the corresponding subunits from spinach. The cross-reactivity of the .gamma. subunit correlated with previous observations that Spirulina membrane ATPase activity can be modulated by light and dithiothreitol, in a similar fashion to their effect on the enzyme from spinach chloroplasts. The ability of cyanobacterial and chloroplast enzymes to restore activity to heterologous membranes in the absence of immunological similarities between their respective .delta. and .epsilon. subunits may suggest that structural features other than particular amino acid sequences of these subunits are paramount in their roles in binding f1 to the membrane and in sealing proton leaks.

关键词： Coupling factor Photophosphorylation ATPase Reconstitution (Spirulina, Spinach, Chloroplast) f 1 factor 1 or ATP synthase Cf 1 chloroplast f 1 Chl chlorophyll f 0 hydrophobic membrane polypeptide assembly

来源：评论

学校读者我要写书评

暂无评论

PROTON PUMPING AND ELECTRON-TRANSfER IN THE CYTOCHROME B/f COMPLEX Of ALGAE

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第2期849卷 211-222页

作者： JOLIOT, P JOLIOT, A Institut de Biologie Physico-Chimique 13 rue Pierre et Marie Curie 75005 Paris France

The electron-transfer reactions and the slow transmembrane electrogenic phase (phase b) have been studied in Photosystem-II-depleted mutant strains of Chlorella sorokiniana under anaerobic conditions. The dark reduction of cytochrome b previously oxidized by a strong illumination is a biphasic process. The first phase, completed in about 20 s, is associated with the reduction of the high-potential form of cytochrome b;a slower phase, completed in about 10 min, is associated with the reduction of the low-potential form of cytochrome b. The .alpha.-bands of these two forms differ slightly. Under repetitive weak flash illumination, i.e., when a fraction of cytochrome b is oxidized prior to each flash, phase b is associated with minor changes in cytochrome b redox changes. In the presence of 2-n-nonyl-4-hydroxyquinoline N-oxide (NQNO), a large reduction of cytochrome b (t1/2 .apprxeq. 2 ms) is followed by a slow reoxidation. Under these conditions, phase b becomes biphasic, a first phase, insensitive to the inhibitor, is associated with cytochrome b reduction while the second phase, dependent upon the inhibitor concentration, is related to cytochrome b oxidation. These results are interpreted in terms of a modified Q-cycle model. A single weak flash given to dark-adapted algae, i.e., when the two b cytochromes are in their reduced state, induces a large cytochrome b oxidation with which is associated a phase b of longer duration but larger amplitude than the one observed under repetitive-flash illumination. Addition of 2-n-nonyl-4-hydroxyquinoline N-oxide inhibits neither the oxidation of cytochrome b nor phase b. These results suggest that a proton pump is coupled to the redox changes of plastoquinone occurring at a site, Z, close to the inner face of the membrane. This model implies that site Z is connected to the outer face of the thylakoid by a proton channel. Thus, depending upon the experiment conditions, two different mechanisms might be involved in the process o

关键词： Proton pump Electron transfer Cytochrome b f complex Plastoquinone Cytochrome b (Chlorella) PS Photosystem PQ plastoquinone PQH 2 plastoquinol PQ − plastosemiquinone cytochrome b or Cyt b cytochrome b 6 Cyt f cytochrome f HQNO 2- n -heptyl-4-hydroxyquinoline N -oxide NQNO 2- n -nonyl-4-hydroxyquinoline N -oxide

来源：评论

学校读者我要写书评

暂无评论

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第1期854卷 102-108页

作者： MORIYAMA, Y TAKANO, T OHKUMA, S TEIKYO UNIV FAC PHARMACEUT SCI DEPT MICROBIOL & MOLEC PATHOL SAGAMIKO KANAGAWA 19901 JAPAN

Lysosomal H+-translocating ATPase (H+-ATPase) was solubilized with lysophosphatidylcholine and reconstituted into liposomes (Moriyama, Y., Takano, T. and Ohkuma, S. (1984) J. Biochem. (Tokyo) 96, 927-930). In this study, the sensitivities of membrane-bound, solubilized and liposome-incorporated ATPase to various anions and drugs were measured in comparison with those of similar forms of mitochondria H+-ATPase (mitochondrial f0f1-ATPase) with the following results. (1) Bicarbonate and sulfite activated solubilized lysosomal H+-ATPase, but not the membrane-bound ATPase or ATPase incorporated into liposomes. All three forms of mitochondrial f0f1-ATPase were activated by these anions. (2) All three forms of both lysosomal H+-ATPase and mitochondrial f0f1-ATPase were strongly inhibited by SCN-, NO3- and f-, but scarcely affected by Cl-, Br- and SO42-. (3) The solubilized lysosomal H+-ATPase was strongly inhibited by azide, quercetin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl), 4-acetamido-4''-isothiocyanatostilbene-2,2''-disulfonic acid (SITS), 4,4''-diisothiocyanatostilbene-2,2''-disulfonic acid (DIDS) and oligomycin. Its sensitivity was almost the same as that of mitochondrial f0f1-ATPase. Neither membrane-bound ATPase nor ATPase incorporated into liposomes was affected appreciably by these drugs. These results indicate that the sensitivity to anions and drugs of lysosomal H+-ATPase depends on the form of the enzyme and that the sensitivity of the solubilized lysosomal H+-ATPase is very similar to that of mitochondrial f0f1-ATPase. On the other hand, the two ATPases differ in their sensitivity to N-ethylmaleimide and pyridoxal phosphate;only the mitochondrial ATPase is inhibited by pyridoxal phosphate whereas only the lysosomal ATPase is inhibited by N-ethylmaleimide.

关键词： f 0 f 1 -ATPase H + -ATPase Membrane reconstitution Anion sensitivity (Rat liver) Bicine N,N- bis (2- hydroxyethyl)glycine DCCD N,N′- dicyclohexylcarbodiimide DIDS 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid NBD-Cl 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole SITS 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid TMAH tetramethylammonium hydroxide

来源：评论

学校读者我要写书评

暂无评论

DEMONSTRATION Of 2 EXCHANGEABLE NONCATALYTIC AND 2 COOPERATIVE CATALYTIC SITES IN ISOLATED BOVINE HEART MITOCHONDRIAL f1, USING THE PHOTOAffINITY LABELS [2-H-3]8-AZIDO-ATP AND [2-H-3]8-AZIDO-ADP

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第1期850卷 121-130页

作者： VANDONGEN, MBM BERDEN, JA Laboratory of Biochemistry University of Amsterdam P.O. Box 20151 1000 HD Amsterdam The Netherlands

The photoreactive nucleotides [2- 3 H]8-azido-ATP and [2- 3 H]8-azido-ADP could be used to label the nucleotide binding sites on isolated mitochondrial f 1 -ATPase to a maximum of 4 mol of nucleotide per mol f 1 , also when the f 1 was depleted of tightly bound nucleotides. At a photolabel concentration of 300–1000 μM, label was found on both α and β subunits in a typically 1:3 ratio, independent of the total amount bound. Under these conditions the covalent binding of two nucleotides is needed for full inactivation (Wagenvoord, R.J., Van der Kraan, I. and Kemp, A. (1977) Biochim. Biophys. Acta 460, 17–24). At lower concentrations of [2- 3 H]8-azido-ATP (20 μM), it was found that covalent binding of only 1 mol of nucleotide per mole f 1 was required for complete inactivation to take place indicating catalytic site cooperativity in the mechanism of ATP hydrolysis. Under those conditions, radioactivity was only found on the β subunits, which would indicate that the catalytic site is located on a β subunit and that a second site is located on the α/β interface. It is found that four out of the six nucleotide binding sites are exchangeable and can be labelled with 8-azido-AT(D)P, i.e., two catalytic sites and two non-catalytic sites.

关键词： 8-Azido-ATP 8-Azido-ADP f 1 -ATPase Photoaffinity labelling Cooperative catalytic site 8-N-ATP 8-nitreno-adenosine-5′-triphosphate Mes 4-morpholineethanesulphonic acid Mops 4-morpholine-propanesulphonic acid NAP 3 3′ O -[3-[ N -(4-azido-2-nitrophenyl)-amino]propionyl

来源：评论

学校读者我要写书评

暂无评论

STUDIES ON THE CYTOCHROME B6/f COMPLEX .2. LOCALIZATION Of THE COMPLEX IN THE THYLAKOID MEMBRANES fROM SPINACH AND CHLAMYDOMONAS-REINHARDTII BY IMMUNOCYTOCHEMISTRY AND fREEZE-fRACTURE ANALYSIS Of B6/f MUTANTS

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第2期851卷 239-248页

作者： OLIVE, J VALLON, O WOLLMAN, fA RECOUVREUR, M BENNOUN, P UNIV PARIS 07 INST JACQUES MONOD MICROSCOPIE ELECTR LAB CNRS 2 PL JUSSIEU F-75251 PARIS 05 FRANCE INST BIOL PHYS CHIM SERV PHOTOSYNTHESE F-75231 PARIS 05 FRANCE

The distribution of the b6/f complex among stacked and unstacked thylakoid membranes was studied by immunocytochemistry and freeze-fracture analysis of mutants of Chlamydomonas reinhardtii lacking the complex. Immunogold labeling demonstrates the presence of b6/f complex in both regions of the thylakoid membrane in spinach and in C. reinhardtii. Numerous modifications were observed in the ultrastructure of the thylakoid membranes of mutants from C. reinhardtii lacking the complex. These modifications are consistent with the presence of b6/f complexes in different states of association in the stacked and unstacked regions of the thylakoid membrane. In particular we present evidence for an association of some b6/f complexes with the reaction centers of Photosystem I and II in large Pfu and Efs particles, respectively.

关键词： Cytochrome b 6 / f complex freeze-fracture Immunocytochemistry Thylakoid membrane Membrane stacking ( C. reinhardtii ) Ef exoplasmic fracture face Pf protoplasmic fracture face s stacked u unstacked PS Photosystem Cyt cytochrome DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea TMBZ 3,3′,5,5′-tetramethylbenzidine

来源：评论

学校读者我要写书评

暂无评论

REMOVAL Of THE EPSILON-SUBUNIT fROM ESCHERICHIA-COLI f1-ATPASE USING MONOCLONAL ANTI-EPSILON ANTIBODY-AffINITY CHROMATOGRAPHY

引用

ANALYTICAL BIOCHEMISTRY 1986年第1期159卷 35-42页

作者： DUNN, SD UNIV WESTERN ONTARIO DEPT BIOCHEM LONDON N6A 5C1 ONTARIO CANADA

The usefulness of two monoclonal antibodies .epsilon.-1 and .epsilon.-4, which recognize the .epsilon. subunit of Escherichia coli f1-ATPase, for removing that subunit from ATPase was assessed. The .epsilon. subunit is a tightly bound, but dissociable, inhibitor of the ATPase. .epsilon.-1 binds .epsilon. with 10-fold higher affinity than .epsilon.-4. .epsilon.-1 recognizes a site on .epsilon. which is hidden by the quaternary structure of ATPase, while .epsilon.-4 can recognize .epsilon. when it is part of ATPase. Each antibody was purified and coupled to Sepharose to generate affinity columns. Solutions of ATPase in a buffer which was designed to reduce the affinity of .epsilon. for the enzyme were pumped through the columns and the degree of .epsilon. depletion was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by Western blotting. Neither column retained ATPase significantly. At low ATPase concentrations and low flow rates, the .epsilon.-1 column was more efficient than the .epsilon.-4 column, removing in excess of 95% of the .epsilon. in a single passage compared with 93% removal by the .epsilon.-4 column. At higher protein concentrations or flow rates, however, the performance of the .epsilon.-1 column was substantially poorer, while that of the .epsilon.-4 column was much less affected. Very little .epsilon. emerged from the .epsilon.-4 column before most of the measured .epsilon.-binding capacity was filled. A second passage through the .epsilon.-4 column reduced residual .epsilon. to less than 2% of that which was originally present. Pure, active .epsilon. was eluted from either column by 1 M NH4OH, pH 11. The relatively poor performance of .epsilon.-1 is discussed in terms of the low availability of the epitope and the tendency of the .epsilon.-depleted complex to compete with .epsilon.-1 for residual .epsilon. subunit. from consideration of these factors it appears likely that antibodies which recognize exposed epitopes will ge

关键词： f 1 -ATPase affinity chromatography monoclonal antibodies protein/enzyme purification subunit removal

来源：评论

学校读者我要写书评

暂无评论

SPATIAL-ORGANIZATION Of THE CYTOCHROME B6-f COMPLEX WITHIN CHLOROPLAST THYLAKOID MEMBRANES

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1986年第1期849卷 94-103页

作者： ALLRED, DR STAEHELIN, LA UNIV COLORADO DEPT MOLEC CELLULAR & DEV BIOL BOULDER CO 80309 USA

The spatial distribution of the chloroplast thylakoid protein complex of cytochromes f and b-563, and the Rieske iron-sulfur protein (Cyt b6-f) has been controversial because of conflicting results obtained by different techniques. We have combined the following biochemical and immunochemical techniques to approach this question: (1) french press disruption of thylakoids, followed by repeated two-phase aqueous polymer partitioning to separate inside-out grana from right-side-out stroma membrane fragments;(2) electrophoretic analysis followed by the 3,3'',5,5''-tetramethylbenzidine stain for cytochrome hemes;(3) electroblot analysis with anti-Cyt b6-f antibodies;(4) agglutination of membrane fragments with anti-Cyt b6-f antibodies;and (5) post-embedment thin-section immunolabeling of chemically fixed or ultrarapidly frozen chloroplasts with anti-Cyt b6-f antibodies. Our results indicate that the complex is present in both of the isolated membrane fragment populations in similar amounts, with the bulk of the immunoreactive sites exposed to the thylakoidal lumen. Direct immunolabeling of thin-sectioned chloroplasts resulted in localization of the complex throughout the thylakoids, without specialized compartmentation. These results provide both the temporal and spatial resolution necessary for accurate localization of the complex. We concur with models proposing distribution of Cyt b6-f throughout all thylakoid membranes.

关键词： Cytochrome b 6 - f complex Spatial distribution Cf 0 Cf 1 ATP synthase Thylakoid membrane Membrane organization (Pea, Spinach chloroplasts) Cyt cytochrome PS Photosystem TMBZ tetramethylbenzidine Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-glycine

来源：评论

学校读者我要写书评

暂无评论

TRANSPORT Of f1-ATPASE SUBUNIT-BETA INTO MITOCHONDRIA DEPENDS ON BOTH A MEMBRANE-POTENTIAL AND NUCLEOSIDE TRIPHOSPHATES

引用

fEBS LETTERS 1986年第2期209卷 152-156页

作者： PfANNER, N NEUPERT, W Institut für Physiologische Chemie Universität München Goethestr. 33 D-8000 München 2 FRG

Transport of cytoplasmically synthesized precursor proteins into or across the inner mitochondrial membrane requires a mitochondrial membrane potential. We have studied whether additional energy sources are also necessary for protein translocation. Reticulocyte lysate (containing radiolabelled precursor proteins) and mitochondria were depleted of ATP by pre-incubation with apyrase. A membrane potential was then established by the addition of substrates of the electron transport chain. Oligomycin was included to prevent dissipation of delta psi by the action of the f0f1-ATPase. Under these conditions, import of subunit beta of f1-ATPase (f1 beta) was inhibited. Addition of ATP or GTP restored import. When the membrane potential was destroyed, however, the import of f1 beta was completely inhibited even in the presence of ATP. We therefore conclude that the import of f1 beta depends on both nucleoside triphosphates and a membrane potential.

关键词： Mitochondria Protein import Membrane potential tATP f 1 -ATPase

来源：评论

学校读者我要写书评

暂无评论

VOLUME LOADING HYPOALGESIA IN SHR, WKY AND f1 OffSPRING Of A SHR X WKY CROSS

引用

BRAIN RESEARCH 1986年第1期363卷 178-182页

作者： RANDICH, A UNIV IOWA DEPT PSYCHOL IOWA CITY IA 52242 USA

The effects of volume loading on a nociceptive reflex, arterial blood pressure and heart rate were studied in spontaneously hypertensive rats (SHRs), Wistar Kyoto normotensive rats (WKYs) and the f1 offspring of a SHR .times. WKY cross. Volume loading resulted in significantly greater inhibition of the tail-flick reflex to painful radiant heat in SHRs compared to WKYs. The f1 offspring of a SHR .times. WKY cross showed levels of hypoalgesia to volume loading that were intermediate to those of SHRs and WKYs. There were no differences between these strains in their hypotensive and bradycardic responses to volume loading. These findings are discussed in terms of cardiovascular-somatosensory interactions.

关键词： volume loading hypoalgesia tail-flick spontaneously hypertensive rat (SHR) Wistar Kyoto normotensive rat (WKY) f 1 offspring of SHR × WKY

来源：评论

学校读者我要写书评

暂无评论

PUTATIVE AMINO-TERMINAL PRESEQUENCE fOR BETA-SUBUNIT Of PLANT MITOCHONDRIAL f1ATPASE DEDUCED fROM THE AMINO-TERMINAL SEQUENCE Of THE MATURE SUBUNIT

引用

fEBS LETTERS 1986年第2期203卷 144-148页

作者： KOBAYASHI, K IWASAKI, Y SASAKI, T NAKAMURA, K ASAHI, T NAGOYA UNIV BIOCHEM LABNAGOYAAICHI 464JAPAN NAGOYA UNIV FAC AGRPHYS CHEM LABNAGOYAAICHI 464JAPAN

The α- and β-subunits of sweet potato mitochondrial f 1 ATPase were purified from the f 1 complex by gel filtration and ion-exchange high-performance liquid chromatography. Isoelectric focussing and N-terminal amino acid sequencing indicated that the purified β-subunit contains at least two polypeptides similar to each other. The N-terminal 18 amino acid sequence of the β-subunit showed homology to the amino acid sequence of the tobacco mitochondrial f 1 ATPase β-subunit precursor deduced from the nucleotide sequence [(1985) EMBO J. 4, 2159-2165] between residues 56 and 73, suggesting that the N-terminal 55 amino acids of the tobacco precursor constitute the presequence required for mitochondrial targetting.

关键词： (Plant) Mitochondria Organelle biogenesis f 1 ATPase β-Subunit Nuclear-encoded subunit Presequence DEAE diethylaminoethyl

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：