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ELECTRON-TRANSfER BETWEEN THE 2 PHOTOSYSTEMS .1. fLASH EXCITATION UNDER OXIDIZING CONDITIONS

BIOCHIMICA ET BIOPHYSICA ACTA 1984年第2期765卷 210-218页

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

The redox changes of cytochrome b-563 (cytochrome b), cytochrome f, plastocyanin and P-700 were measured on dark-adapted chloroplasts [spinach] after illumination by a series of flashes in oxidizing conditions (0.1 mM ferricyanide). In these conditions, the plastoquinone pool is fully oxidized and the only available plastoquinol are those formed by Photosystem (PS) II reaction. According to the 2-electron gate mechanism proposed by Bouges-Bocquet plastoquinol is mainly formed after the 2nd and the 4th flashes. After the 2nd flash, the reoxidation of plastoquinol occurs by a concerted reaction which reduces most of the cytochrome b present and a fraction of PS I donors. Most of these electrons are stored on P-700, which implies a large equilibrium constant between the secondary PS I donors and P-700. One electron is stored on cytochrome b during a time (t1/2 .apprxeq. 1 s) much longer than the dark interval between flashes. After the 4th flash, a new plastoquinol molecule is formed, which induces the reduction of PS I donors with no corresponding further reduction of cytochrome b. The number of electrons transferred after the 4th flash is larger than that transferred after the 2nd flash although the rate of transfer is lower. To interpret these data, we assume that the plastoquinol formed after the 4th flash is reoxidized by a 2nd concerted reaction: 1 electron is directly transferred to PS I donors while the other cooperates with the electron stored on cytochrome b to reduce a plastoquinone molecule localized on a site close to the outer face of the membrane. This newly formed plastoquinol crosses the membrane and transfers a second electron to PS I donors. This interpretation resembles a model proposed by Velthuys and which belongs to the modified Q-cycle class of models.

关键词： Electron transfer Cytochrome b -563 Cytochrome f Plastoquinone Photosynthesis (Spinach chloroplast) PS Photosystem PQ plastoquinone cyt b or cytochrome b cytochrome b -563 cyt f cytochrome f PC plastocyanin HQNO 2-heptyl-4-hydroxyquinoline N -oxide DCMU 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea

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ASSESSMENT Of ELASTIC-MODULUS Of CONCRETE AND ITS INfLUENCE ON STRUCTURAL DESIGN

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CEMENT AND CONCRETE RESEARCH 1984年第5期14卷 705-716页

作者： PASCALE, G DILEO, A Institute of Scienza delle Costruzioni University of Bologna Italy

The present work reports the results of an experimental research on the correlation between the modulus of elasticity and the compressive strength of concrete, which considerably disagrees with the indications provide... 详细信息

关键词： R c ,f c cubic and cylindric compressive strength N · mm −2 R c mean value of R c R ck ,f ck characteristic values of R c and f c respectively E c modulus of elasticity N · mm −2 E o , E d , E s initial tengent, dynamic static modulus of elasticity respectively N · mm −2 E s mean value of E s s standard deviation C v coeffecient of variation f frequency density e percent error of experimental results with regard to the proposed correlation d deflection of mideline cross-section mm g σ critical load N · m −1 σ s normal stress for steel N · mm −2

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PHYCOBILISOME - A MACROMOLECULAR COMPLEX OPTIMIZED fOR LIGHT ENERGY-TRANSfER

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BIOCHIMICA ET BIOPHYSICA ACTA 1984年第1期768卷 29-51页

作者： GLAZER, AN Department of Microbiology and Immunology University of California Berkeyley CA94720U.S.A.

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THE BIOENERGETICS Of METHANOGENESIS

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BIOCHIMICA ET BIOPHYSICA ACTA 1984年第2期768卷 113-163页

作者： DANIELS, L SPARLING, R SPROTT, GD NATL RES COUNCIL CANADA DIV BIOL SCI OTTAWA K1A 0R6 ONTARIO CANADA

The reduction of CO2 or any other methanogenic substrate to methane serves the same function as the reduction of oxygen, nitrate or sulfate to more reduced products. These exergonic reactions are coupled to the production of usable energy generated through a charge separation and a protonmotive-force-driven ATPase. for the understanding of how methanogens derive energy from C-1 unit reduction one must study the biochemistry of the chemical reactions involved and how these are coupled to the production of a charge separation and subsequent electron transport phosphorylation. Data on methanogenesis by a variety of organisms indicates ubiquitous use of CH3-S-CoM as the final electron acceptor in the production of methane through the methyl CoM reductase and of 5-deazaflavin as a primary source of reducing equivalents. Three known enzymes serve as catalysts in the production of reduced 5-deazaflavin: hydrogenase, formate dehydrogenase and CO dehydrogenase. All three are potential candidates for proton pumps. In the organisms that must oxidize some of their substrate to obtain electrons for the reduction of another portion of the substrate to methane (e.g., those using formate, methanol or acetate), the latter two enzymes may operate in the oxidizing direction. CO2 is the most frequent substrate for methanogenesis but is the only substrate that obligately requires the presence of H2 and hydrogenase. Growth on methanol requires a B12-containing methanol-CoM methyl transferase and does not necessarily need any other methanogenic enzymes besides the methyl-CoM reductase system when hydrogenase is present. When bacteria grow on methanol alone it is not yet clear if they get their reducing equivalents from a reversal of methanogenic enzymes, thus oxidizing methyl groups to CO2. An alternative (since these and acetate-catabolizing methanogens possess cytochrome b) is electron transport and possible proton pumping via a cytochrome-containing electron transport chain. Several of

关键词： CCCP carbonyl cyanide m -chlorophenylhydrazone HS-CoM 2-mercaptoethanesulphonate DCCD N , N ′-dicyclohexylcarbodiimide fCCP carbonyl cyanide p -trifluoromethoxyphenylhydrazone f 342 degradation product of carboxymethanopterin that fluoresces at 342 nm f 420 a 8-hydroxy 5-deazaflavin f 430 nickel tetrapyrrole cofactor of the methyl reductase ΔG O ′ Gibbs free energy TCS tetrachlorosalicylanilide TPB − tetraphenylboron anion TPMP + triphenylmethylphosphonium cation Y ATP g cell produced per mol ATP YfC yellow fluorescing compound YfC carboxymethanopterin YfC formylmethanopterin fAf formaldehyde activating factor CDR methanofuran CDR carbon dioxide reduction factor X i intracytoplasmic X X o exocellular X

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ACTIONS Of AMANTADINE AT SYNAPTIC AND EXTRASYNAPTIC CHOLINERGIC RECEPTORS IN THE CENTRAL NERVOUS-SYSTEM Of THE COCKROACH PERIPLANETA-AMERICANA

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JOURNAL Of INSECT PHYSIOLOGY 1984年第3期30卷 185-190页

作者： ARTOLA, A CALLEC, JJ HUE, B DAVID, JA SATTELLE, DB UNIV CAMBRIDGE DEPT ZOOL ARC INSECT NEUROPHYSIOL & PHARMACOL UNIT CAMBRIDGE CB2 3EJ ENGLAND FAC MED ANGERS PHYSIOL LAB F-49045 ANGERS FRANCE UNIV RENNES 1 UER SCI VIE & ENVIRONM PHYSIOL ANIM LAB F-35042 RENNES FRANCE

The effects of amantadine were investigated on cercal afferent, giant interneuron synapses and on the cell body membrane of the fast coxal depressor motoneuron (Df), in P. americana. Bath-applied amantadine at concentrations above 2.0 .times. 10-5 M, significantly reduced the amplitude of urinary and compound epsps recorded by sucrose-gap methods from cercal afferent, giant interneuron synapses in the desheathed 6th abdominal ganglion. Complete block of synaptic transmission was achieved at 1.0 .times. 10-3 M amantadine. Synaptic blockade, which was not accompanied by changes in resting potential, was almost fully reversed by washing the ganglion in normal saline. from the dose-dependence of the synaptic blocking action, a Hill coefficient of 0.94 was estimated, indicating that there is no co-operativity in the binding of amantadine to its site of action. Bath-application of amantadine (5.0 .times. 10-5 M) resulted in a parallel shift to the right of the dose-response curve for the depolarizing postsynaptic actions of acetylcholine. Nevertheless, even at a concentration of 2.0 .times. 10-3 M, amantadine failed to protect the synaptic acetylcholine receptor/ion channel complex from the blocking action of .alpha.-bungarotoxin (5.0 .times. 10-7 M). In addition, the block by amantadine of the acetylcholine-induced current recorded from the cell body membrane of the fast coxal depressor motoneuron (Df), was strongly dependent on membrane potential in the range -120mV to -70mV. An action of amantadine at the open acetylcholine receptor/ion channel complex is proposed.

关键词： Amantadine acetylcholine receptor/ion channel cockroach central synapses fast coxal depressor motoneurone (D f ) oil-gap sucrose-gap voltage-clamp

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INfLAMMATORY MEDIATORS AND MECHANISMS Of RELEASE fROM PURIfIED HUMAN BASOPHILS AND MAST-CELLS

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JOURNAL Of ALLERGY AND CLINICAL IMMUNOLOGY 1984年第4期74卷 473-481页

作者： SCHLEIMER, RP MACGLASHAN, DW PETERS, SP NACLERIO, R PROUD, D ADKINSON, Nf LICHTENSTEIN, LM JOHNS HOPKINS UNIV GOOD SAMARITAN HOSPSCH MEDDIV CLIN IMMUNOLBALTIMOREMD 21239

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DROSOPHILA-MELANOGASTER ALCOHOL-DEHYDROGENASE - SUBSTRATE STEREOSPECIfICITY Of THE ADHf ALLELOENZYME

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INSECT BIOCHEMISTRY 1984年第3期14卷 345-351页

作者： HOVIK, R WINBERG, JO MCKINLEYMCKEE, JS Biochemical Institute University of Oslo P.O. Box 1041 Blindern Oslo 3 Norway

The substrate specificity and the stereospecificity of the Adhf [fast alcohol dehydrogenase] alleloenzyme from D. melanogaster were investigated. These properties like the topology of the alcohol binding region and the mechanism of oxidation of primary and secondary alcohols are similar to that of the AdhS and Adhuf [slow and ultrafast, respectively] alleloenzymes. Adhf like Adhuf, binds the coenzyme-competitive inhibitor Cibacron blue much more weakly than does the AdhS alleloenzyme. This shows that amino acid residue 192 affects coenzyme binding. It also accounts for the observed differences between the activities of these alleloenzymes with respect to their maximum velocity (Vm) with secondary alcohols as substrates.

关键词： Alcohol dehydrogenase Drosophila melanogaster substrate stereospecificity Adh alcohol dehydrogenase Adh f Adh S and Adh Uf , fast, slow and ultrafast alcohol dehydrogenase (EC 1.1.1.1) from the fruitfly Drosophila melanogaster

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PERSISTENCE Of THE IMMUNOPROTECTIVE EffECTS Of LEUKEMIA X fIBROBLAST HYBRID-CELLS TOWARD LEUKEMIA IN HISTOCOMPATIBLE MICE

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LEUKEMIA RESEARCH 1984年第2期8卷 255-&页

作者： GARBER, SL COHEN, EP CHANG, I UNIV ILLINOIS DEPT MICROBIOL & IMMUNOLCHICAGOIL 60612

Hybrids of ASL-1 murine leukemia cells and LM(TK-) cells, a cultured line of mouse fibroblast origin, stimulate partial immunity toward ASL-1 cells in (A/J X C3H/HeJ)f1 mice (f1 mice). Such mice ordinarily exhibit no resistance to the malignant proliferation of ASL-1 cells. Unprotected animals invariably die within 14-18 days after receiving as few as 200 ASL-1 cells. The hybrid cells, the mice used in the experimental studies and the leukemia cells used for challenge all share the same histocompatibility antigens. ASL-1 cells are H-2a; LM(TK-) cells are H-2k, both ASL-1 X LM(TK-) hybrid cells and A/J X C3H/HeJ)f1 mice are H-2a/k. The long-term persistence of the immunoprotective properties of the hybrid cells toward murine leukemia was investigated by using cells that had been in continuous culture for approx. 36 months. (A/J X C3H/HeJ)f1 mice injected previously with hybrid cells in continuous culture and then challenged with up to 10(7) ASL-1 cells survived longer (p less than 0.001) than mice who had not received hybrid cells previously. Some mice challenged with lesser number of ASL-1 cells survived indefinitely (greater than 200 days). The median survival time of f1 mice injected simultaneously with 10(7) hybrid cells and 200 or 2000 ASL-1 cells was significantly (p less than 0.001) prolonged as well, although the differences between experimental and control groups are less pronounced than if the hybrid cells were injected before challenge with ASL-1 cells. The hybrid cells like those freshly prepared continue to be rejected by histocompatible precipients. In no instance has there been evidence of a progressively growing tumor of hybrid cells in immunocompetent f1 mice. Hybrid cells like those investigated previously do form rapidly growing metastasizing tumors in immunodeficient nu/nu (BALB/c) or X-irradiated (550 R) f1 mice. The cells possess approx. 70 chromosomes (reduced from 85) including chromosomes identified as having originated in each parental sourc

关键词： Hybrid cells murine leukemia immunity toward survival histocompatible ASL -1 × LM ( TK -) hybrid cells hybrid cells ( A J × C3H HeJ )f 1 mice f 1 mice hypoxanthine, aminopterin, thymidine HAT

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THE EffECT Of PERIODIC DARK INTERRUPTIONS IN LONG PHOTOPERIODS ON fLORAL INDUCTION IN THE LONG-DAY PLANTS SILENE-ARMERIA L, ANNUAL LUNARIA-ANNUA L AND SAMOLUS-PARVIfLORUS RAf

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JOURNAL Of PLANT PHYSIOLOGY 1984年第3期117卷 257-265页

作者： WELLENSIEK, SJ Department of Horticulture Agricultural University P.O.B. 30 NL 6700 AA Wageningen The Netherlands Publication 510.

After a basic fluorescent and incandescent illumination, a period of incandescent illumination was interrupted by 3 h of darkness at different times, the total light period always being 16 h. After these Day Interruption (DI) treatments of various durations the plants were transferred to long day (LD) or continuous light (CL), where the numbers of days of flower-bud visibility were recorded. Compared with the uninterrupted controls, the DI-treatments generally accelerated flower formation to an extent which varied rhythmically with the moment in the photoperiod at which the DI was given. By involving the days to flower-bud visibility in LD or CL of originally vegetative plants in the evaluation of the results, the DI-effects could be explained as the reflection of rhythmically returning changes in the light requirement for flower formation in the course of the photoperiod. Relatively rapid flower formation after a certain DI treatment reflected a relatively low light requirement, and vice versa. Calculations of the inductive efficiencies of interrupted regions, defined as their inductive effect as percentages of the effect of LD or CL, confirmed this viewpoint. The rhythmic courses of the light requirement during the photoperiod could be distinguished as 2 types: the Silene type, to which also Lunaria belongs: photoperiodic light requirement starting relatively low, next not or slowly increasing, finally sharply increasing;the Salmolus type: photoperiodic light requirement starting relatively high, decreasing to a minimum, then sharply increasing, following a quadratic curve.

关键词： Day interruption inductive efficiency light requirement for flower formation Lunaria annua L. photoperiodism rhythmicity of flower formation Samolus parviflorus Raf. Silene armeria L. CL continuous light {ie257-1} days to flower-bud visibility, {ie257-2} being the symbol for a flower bud D darkness DI day interruption f fluorescent light h hour(s) I incandescent light LD long day SD short day tr treatment(s) w week(s)

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THE UNC OPERON - NUCLEOTIDE-SEQUENCE, REGULATION AND STRUCTURE Of ATP-SYNTHASE

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BIOCHIMICA ET BIOPHYSICA ACTA 1984年第2期768卷 164-200页

作者： WALKER, JE SARASTE, M GAY, NJ Laboratory of Molecular Biology The Medical Research Council Centre Hills Road Cambridge CB2 2QH U.K.

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