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INTERACTION BETWEEN f1-ATPASE AND ITS NATURALLY-OCCURRING INHIBITOR PROTEIN - STUDIES USING A SPECIfIC ANTI-INHIBITOR ANTIBODY

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BIOCHIMICA ET BIOPHYSICA ACTA 1985年第1期806卷 64-74页

作者： HUSAIN, I JACKSON, PJ HARRIS, DA UNIV LEEDS DEPT BIOCHEM MT PRESTON ST LEEDS LS2 9JT W YORKSHIRE ENGLAND

An antibody was raised to cross-linked ox-heart mitochondrial inhibitor protein, which cross-reacted with the free inhibitor but with no other mitochondrial membrane protein. This antibody yielded an immunoprecipitate with the cross-linked inhibitor protein, but a soluble antibody-antigen complex with free inhibitor. The antibody bound well to inhibitor protein whether the latter was complexed with f1-ATPase or not. Antibody binding had no effect on the ability of the inhibitor protein to inhibit the ATPase activity of f1. These findings suggest that the antibody does not block the site of interaction between the inhibitor and f1. The inhibitor protein content of submitochondrial membrane preparations was determined by radioimmunoassay, activity measurements and an immunochemical back titration technique. The inhibitor content of submitochondrial membrane preparations was determined by radioimmunoassay, activity measurements and an immunochemical back titration technique. The inhibitor content of the membranes was shown to decrease after energization, suggesting a loss of inhibitor from the membranes into solution. Binding antibody to the inhibitor protein on submitochondrial membrane preparations was determined by radioimmunoassay, activity measurements and an immunochemical back titration technique. The inhibitor content of the membranes was shown to decrease after energization, suggesting a loss of inhibitor for the membranes into solution. Binding antibody to the inhibitor protein on submitochondrial particles had no effect on the steady-state rate of phosphorylation, but it increased the lag phase preceding phosphorylation from 30-54 s. The rate constant for the approach to the steady state dropped from 0.078-0.052 s-1. This effect confirmed that the lag phase is due to inhibition of phosphorylation by the inhibitor protein. The increase in ATPase activity following energization takes place by a fast phase (80% maximal activity reached within 90 s) and a slower

关键词： ATPase inhibitor Oxidative phosphorylation Antibody f 1 -ATPase (Bovine heart mitochondria) IgG immunoglobulin G f 1 soluble portion of the coupling ATP synthase complex U (enzyme unit) quantity of enzyme hydrolysing 1 μ mol substrate/min fCCP carbonyl cyanide p -trifluoromethoxyphenylhydrazone Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid

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Irreductibility criteria for the principal series of GL_n(f) in p characteristic

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JOURNAL Of ALGEBRA 2006年第1期304卷 39-72页

作者： Ollivier, Rachel Univ Paris 07 Inst Math Jussieu F-75221 Paris 05 France

Soient p un nombre premier et f un corps p -adique. Parmi les f ¯ p -représentations lisses irréductibles de GL 2 ( f ) ayant un caractère central, L. Barthel et R. Livné ont classifié les sous-quotients d'induites paraboliques et montré qu'il en existe d'autres, qu'ils n'ont pas classifiées et qu'ils ont appelées supersingulières [L. Barthel, R. Livné, Irreducible modular représentations of GL 2 of a local field, Duke Math. J. 75 (2) (1994) 261–292 ; L. Barthel, R. Livné, Modular représentations of GL 2 of a local field : The ordinary, unramified case, J. Number Theory 55 (1995)]. En 2001, C. Breuil a obtenu la classification de ces dernières, dans le cas particulier où f = Q p [C. Breuil, Sur quelques représentations modulaires et p -adiques de GL 2 ( Q p ) I, Compos. Math. 138 (2) (2003) 165–188]. Pour n ⩾ 3 , on ne connaît pas même la classification des f ¯ p -représentations lisses irréductibles de GL n ( f ) qui sont des sous-quotients d'induites paraboliques. Nous nous intéressons ici au cas des séries principales. Le cadre de la caractéristique p fait jouer un rôle particulier à l'unique pro- p -Sylow du sous-groupe d'Iwahori de GL n ( f ) : toute f ¯ p -représentation lisse non nulle de GL n ( f ) possède un vecteur non trivial fixé par ce pro- p -Iwahori. Il est ainsi naturel d'approcher les représentations lisses de GL n ( f ) via l'étude des modules sur la f ¯ p -algèbre de Hecke du pro- p -Iwahori de GL n ( f ) . Les travaux de M.-f. Vignéras sur la structure de cette algèbre ont permis de définir ses modules standards [M.-f. Vignéras, Pro- p -Iwahori Hecke ring and supersingular f ¯ p -représentations, Math. Ann. 331 (3) (2005) 523–556, Erratum in : Math. Ann. 333 (3) (2005) 699–701]. A l'aide des modules standards dits réguliers , nous étudions l'espace des invariants sous l'action du pro- p -Iwahori des séries principales de GL n ( f ) en caractéristique p . Nous en déduisons un critère d'irréductibilité pour ces séries principales.

关键词： Anneau de Hecke du pro- p -Iwahori de GL n ( f ) Modules standards Entrelacements

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PURIfICATION AND PROPERTIES Of THE LATENT f1-ATPASE Of MICROCOCCUS-LYSODEIKTICUS

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BIOCHIMICA ET BIOPHYSICA ACTA 1979年第2期547卷 230-240页

作者： HUBERMAN, M SALTON, MRJ NYU HOSP SCH MED DEPT MICROBIOL NEW YORK NY 10016 USA

The latent coupling factor (f1)-ATPase of M. lysodeikticus [luteus] was purified to homogeneity as determined by a number of criteria including non-denaturing polyacrylamide gel electrophoresis, crossed immunoelectrophoresis and analytical ultracentrifugation. By inclusion of 1 mM phenylmethyl sulfonyl fluoride, a serine protease inhibitor, in the shock-wash step of release of f1 from the membranes, the spontaneous activation of both crude and purified ATPase by endogenous membrane protease(s) could be prevented, thereby yielding a highly latent ATPase preparation. Equilibrium ultracentrifugation of the latent ATPase gave a MW of 400,000. The ATPase contained 5 different subunits .alpha., .beta., .gamma., .delta. and .epsilon. and their MW determined by SDS[sodium dodecyl sulfate]-polyacrylamide gel electrophoresis were 60,000, 54,000, 37,000, 27,000 and 9000, respectively. The subunit composition was determined with 14C-labeled, f1-ATPase prepared from cells grown on medium containing [U-14C]-labeled algal protein hydrolysate. Within the limitations of this method the results tentatively suggest a subunit composition of 3:3:1:1:3.

关键词： f 1 -ATPase Coupling factor (Micrococcus lysodeikticus)

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BAHADUR EffICIENCY Of THE f-TEST

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JOURNAL Of STATISTICAL PLANNING AND INfERENCE 1982年第3期6卷 301-304页

作者： BARKER, L SETHURAMAN, J FLORIDA STATE UNIV DEPT STATTALLAHASSEEFL 32313

Extremal problems in large deviations of the f -statistic are considered. It is shown that the slowest rate of convergence over a specified class of distributions of the f -statistic is slower than exponential, and that the Bahadur efficiency of the f -statistic with respect to some distribution-free competitors is identically zero.

关键词： 60f10 62G10 Ansari-Bradley Statistic Bahadur Efficiency f -statistic Large deviations Moses Ranklike Statistic

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ELECTRON-TRANSPORT fROM CYTOCHROME-B6-f COMPLEXES TO PHOTOSYSTEM-I REACTION CENTER COMPLEXES IN SYNECHOCOCCUS SP IS CYTOCHROME-C-553 A MOBILE ELECTRON CARRIER

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BIOCHIMICA ET BIOPHYSICA ACTA 1985年第1期808卷 39-45页

作者： NANBA, M KATOH, S UNIV TOKYO COLL ARTS & SCI DEPT PURE & APPL SCI MEGURO KU TOKYO 153 JAPAN

Numbers of the Photosystem I reaction center complexes and the cytochrome b6-f complexes with which a cytochrome c-553 molecule can interact within the limiting time of photosynthetic electron transport were examined by measuring flash-induced absorption changes of P-700, cytochrome c-553 and cytochrome f in the thermophilic cyanobacterium Synechococcus sp. The addition of 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) did not affect the common 2 ms half-time of P-700, cytochrome c-553 and cytochrome f reduction, which is ascribed to electron transfer from the plastoquinone pool. The inhibitor decreased amounts of the 3 electron carriers which underwent the 2 ms reduction in the order of cytochrome f, cytochrome c-553 and P-700.. On excitation with weak flashes which oxidized only a small fraction of cytochrome c-553 molecules present in cells, P-700 remained in the oxidized state after the flashes were reduced with electrons from the Rieske center or plastoquinone but not from cytochrome c-553. The ratios of cytochrome c-553 to cytochrome f oxidized at various flash intensities were constant and similar to the ratio of the 2 cytochromes present in cells. Thus, cytochrome c-553 cannot exchange electrons with large numbers of the Photosystem I reaction center complexes and the cytochrome b6-f complexes in the limiting time, but has a mobility sufficient to mediate electron transfer between the 2 complexes, which are present at an unbalanced ratio in Synechococcus cells.

关键词： Cytochrome c -553 Cytochrome f Photosystem I Electron transport ( Synechococcus sp.) Hepes 4-(2-hydroxyethyl)-1-piperazineethane-sulfonic acid DBMIB 2,5-dibromo-3-methyl-6-isopropyl- p -benzoquinone (dibromothymoquinone) DCMU 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea PS Photosystem

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THROMBOXANE-B2 UPTAKE AND METABOLISM IN ISOLATED PERfUSED LUNG IDENTIfICATION AND COMPARISON WITH PROSTAGLANDIN-f2-ALPHA

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BIOCHIMICA ET BIOPHYSICA ACTA 1982年第2期712卷 315-325页

作者： ROBINSON, C PEERS, SH WADDELL, KA BLAIR, IA HOULT, JRS UNIV LONDON KINGS COLL DEPT PHARMACOL LONDON WC2R 2LS ENGLAND

Thromboxane B2 was metabolized in isolated perfused guinea-pig lungs to a product identified by negative ion chemical ionization mass spectrometry as 13,14-dihydro-15-ketothromboxane B2. Conversion was measured by radio TLC and was greater in guinea pig than rat lungs (29.1 vs. 13.8% at 10 ng/ml), but similar in lungs from normal and sensitized guinea pigs. Thromboxane B2 metabolism was less than that of prostaglandin ***. but, like it, was prevented at ***. C and reduced by cycloheximide pretreatment. Tissue to medium ratio in perfused guinea pig lungs was 3.4 for thromboxane B2, but 0.2 for inulin (showing that thromboxane B2 is accumulated within the lung) and was altered after experimental manipulations. Neither lung slices, crude homogenates, cytosolic and microsomal fractions nor purified prostaglandin 15-hydroxydehydrogenase metabolized thromboxane B2 in vitro, although prostaglandin ***. was extensively inactivated. Quantitative partition coefficient and albumin-binding data confirm that thromboxane B2 lacks prominent lipophilicity, implying that cellular uptake in lung must be carrier-mediated. Thromboxane B2 is a substrate for pulmonary degradation which may form a route for the biological inactivation of thromboxane A2. Its resistance to prostaglandin 15-hydroxydehydrogenase as conventionally tested remains paradoxical and is discussed.

关键词： Prostaglandin f 2 α Thromboxane B 2 (Lung)

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Interaction between activated chemokine receptor 1 and fcεRI at membrane rafts promotes communication and f-actin-rich cytoneme extensions between mast cells

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INTERNATIONAL IMMUNOLOGY 2010年第2期22卷 113-128页

作者： fifadara, Nimita H. Beer, freddy Ono, Shoichiro Ono, Santa J. Emory Univ Sch Med Emory Eye Ctr Dobbs Ocular Immunol LabsDept Ophthalmol Atlanta GA 30322 USA Emory Univ Sch Med Dept Pathol & Lab Med Atlanta GA 30322 USA

Chemokines play important regulatory roles in immunity, but their contributions to mast cell function remain poorly understood. We examined the effects of fc epsilon RI-chemokine receptor (CCR) 1 co-stimulation on receptor localization and cellular morphology of bone marrow-derived mast cells. Whereas fc epsilon RI and CCR1 co-localized at the plasma membrane in unsensitized cells, sensitization with IgE promoted internalization of CCR1 molecules. Co-stimulation of fc epsilon RI and CCR1 with antigen and macrophage inflammatory protein-1 alpha was more effective than fc epsilon RI stimulation alone in causing leading edge formation, flattened morphology, membrane ruffles and ganglioside (GM1(+)) lipid mediator release. Co-stimulation resulted in phalloidin-positive cytoneme-like cellular extensions, also known as tunneling nanotubes, which originated at points of calcium accumulation. This is the first report of cytoneme formation by mast cells. To determine the importance of lipid rafts for mast cell function, the cells were cholesterol depleted. Cholesterol depletion enhanced degranulation in resting, sensitized and co-stimulated cells, but not in fc epsilon RI-cross-linked cells, and inhibited formation of filamentous actin(+) cytonemes but not GM1(+) cytonemes. Treatment with latrunculin A to sequester globular-actin abolished cytoneme formation. The cytonemes may participate in intercellular communication during allergic and inflammatory responses, and their presence in the co-stimulated mast cells suggests new roles for CCRs in immunopathology.

关键词： co-stimulation f G actin lipid raft MIP-1 alpha tunneling nanotubes

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INHIBITION Of ELECTRON-TRANSfER AND THE ELECTROGENIC REACTION IN THE CYTOCHROME B/f COMPLEX BY 2-NORMAL-NONYL-4-HYDROXYQUINOLINE N-OXIDE (NQNO) AND 2,5-DIBROMO-3-METHYL-6-ISOPROPYL-P-BENZOQUINONE (DBMIB)

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BIOCHIMICA ET BIOPHYSICA ACTA 1988年第2期933卷 258-268页

作者： JONES, RW WHITMARSH, J UNIV ILLINOIS DEPT PLANT BIOL USDA ARS URBANA IL 61801 USA

We investigated the interaction between the cytochrome b/f complex and plastoquinone by determining the effect of the electron transport inhibitors 2-n-nonyl-4-hydroxy-quinoline N-oxide (NQNO) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) on the flash-induced turnover of cytochromes b6 and f, on the slow phase of the electrogenic reaction (515s) and on steady-state electron transport. The experiments were performed using thylakoid membranes in the presence of duroquinol, methyl viologen, and diuron, conditions in which electron transport is driven by Photosystem I and includes the cytochrome b/f complex. The data from these experiments indicate that NQNO and DMBIB inhibit at two different sites on the cytochrome b/f complex. The data can be accommodated by a modified Q-cycle in which the primary site of inhibition by NQNO is the quinone reductase site (Qc) and the primary site of DBMIB inhibition is the quinol oxidase site (Qz). NQNO is envisioned to inhibit the oxidation of the cytochrome b6-heme located nearest the outer aqueous phase, as well as to slow electron transfer between the two b-hemes. The effect of NQNO on the 515s supports the notion that the slow electrogenic reaction is due to electron transfer between the two cytochrome b6-hemes, followed by a reaction associated with plastoquinone reduction at the Qc-site (Jones and Whitmarsh (1985) Photobiochem. Photobiophys. 9, 119-127). The results indicate that the Qz-site and Qc-site are likely separated by 70% of the dielectrically weighted distance across the membrane. At low concentrations of DBMIB the kinetics of the 515s and cytochrome b6 reduction are monophasic, indicating that DMBIB moves from one inhibitory site to another within the turnover time of the cytochrome b/f complex. This observation suggests that the debinding rate of DBMIB on the extent of cytochrome f oxidation and the rate of cytochrome f reduction, raises the possibility that DBMIB has a second lower affinity binding sit

关键词： Cytochrome b f complex Electron transport inhibition Slow electrogenic step Binding site C 50 the concentration of inhibitor required to give 50% of the maximum inhibitory effect cytochrome b f complex plastoquinol-plastocyanin oxidoreductase complex DBMIB 2,5-dibromo-3-methyl-6-isopropyl- p -benzoquinone DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea DQH 2 duroquinol HQNO 2- n -heptyl-4-hydroxyquinoline N -oxide I 50 the concentration of inhibitor required for 50% inhibition of the control signal NQNO 2- n -nonyl-4-hydroxyquinoline N -oxide P-700 + the oxidized primary electron donor of Photosystem I Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)-ethyl]glycine UHDBT 5-( n -undecyl)-6-hydroxy-4,7-dioxobenzothiazole Q c putative quinone binding site on the cytochrome b f complex located near the outer aqueous phase (stroma) Q z putative quinol binding site on the cytochrome b f complex located near the inner aqueous phase (lumen) 515 s the slow phase of the electrochromic shift (rise time 3–5 ms) Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine

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Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activity

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NATURAL PRODUCT RESEARCH 2022年第20期36卷 5311-5318页

作者： Kamdoum, Blaise Cedric Simo, Ingrid Wouamba, Steven Collins Njonte Tchatat Tali, Brice Mariscal Ngameni, Bathelemy fotso, Ghislain Wabo Ambassa, Pantaleon fabrice, fekam Boyom Lenta, Bruno Ndjakou Sewald, Norbert Ngadjui, Bonaventure Tchaleu Univ Yaounde I Dept Organ Chem Fac Sci Yaounde Cameroon Univ Dschang Dept Chem Fac Sci Dschang Cameroon Univ Yaounde I Higher Teacher Training Coll Dept Chem Yaounde Cameroon Univ Yaounde I Dept Biochem Fac Sci Yaounde Cameroon Univ Yaounde I Fac Med & Biomed Sci Dept Pharm Yaounde Cameroon Bielefeld Univ Organ & Bioorgan Chem Fac Chem Bielefeld Germany

An extensive phytochemical investigation of the EtOH/H2O (7:3) extracts of Sida rhombifolia L. and Sida acuta Burm. f., yielded a previously undescribed ceramide named rhombifoliamide (1) and a xylitol dimer (2), naturally isolated here for the first time, as well as the thirteen known compounds viz, oleanolic acid (3), beta-amyrin glucoside (4), ursolic acid (5), beta-sitosterol glucoside (6), tiliroside (7), 1,6-dihydroxyxanthone (8), a mixture of stigmasterol (9) and beta-sitosterol (10), cryptolepine (11), 20-Hydroxyecdysone (12), (E)-suberenol (13), thamnosmonin (14) and xanthyletin (15). Their structures were elucidated by the analyses of their spectroscopic and spectrometric data (1 D and 2 D NMR, and HRESI-MS) and by comparison with the previously reported data. The crude extracts, fractions, and some isolated compounds were tested against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum strains. All the tested samples demonstrated moderate and/or significant activities against 3D7 (IC50 values: 0.18-20.11 mu g/mL) and Dd2 (IC50 values: 0.74-63.09 mu g/mL).

关键词： Sida rhombifolia L Sida acuta Burm f Malvaceae rhombifoliamide xylitol dimer antiplasmodial activities

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

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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

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