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PH-DEPENDENCE Of OXYGEN EVOLUTION AND REDUCTION KINETICS Of PHOTOOXIDIZED CHLOROPHYLL-AII (P-680) IN PHOTOSYSTEM-II PARTICLES fROM SYNECHOCOCCUS SP

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第1期890卷 23-31页

作者： SCHLODDER, E MEYER, B Max-Volmer-Institut für Biophysikalische und Physikalische Chemie Technische Universität Berlin 1000 Berlin 12 F.R.G.

The oxygen flash yield and the kinetics of Chl a + II (P-680 + ) reduction have been measured under repetitive excitation as a function of pH between pH 4.0 and pH 9.0 in oxygen-evolving PS II particles from Synechococcus sp. (i) The optimum of oxygen yield is observed between pH 6.5 and pH 7.5. The inhibition in the acidic pH region is reversible and can be described by a monoprotic binding site with a p K value of about 4.5. In the alkaline pH region the inhibition is half maximal at pH 8.3 and might be described by the titration of three binding sites or more. The loss of oxygen evolution at pH 9.0 is caused by reversible inhibition and irreversible inactivation. (ii) Between pH 4.0 and pH 7.5 the fraction of Chl a + II decaying in the nanosecond time range and the oxygen yield follow the same pH dependence. (iii) Both in Photosystem II centers reversibly inhibited at low pH and in Photosystem II centers inactivated at high pH, Chl a + II is reduced by a donor Z, different from the normal immediate donor D 1 or a modified state of D 1 , and, in part, by back reaction. (iv) Below pH 5.0, the decay in the nanosecond range can be explained by the existence of two phases with t 1 2 ≈ 42 ns and t 1 2 ≈ 300 ns (ratio of amplitudes, 1.3:1). A reduction phase with t 1 2 = 20 ns that is the major phase around the pH optimum is not observed below pH 5.0.

关键词： Oxygen evolution Photosystem II pH effect P-680 ( Synechococcus ) Q A primary quinone acceptor of Photosystem II Chl chlorophyll Mes 4-morpholineethanesulphonic acid PS I Photosystem I PS II Photosystem II D 1 immediate electron donor to Chl a + II D 2 electron carrier between D 1 and the oxygen-evolving complex Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine Z electron donor to Chl a + II after inhibition of O 2 evolution characterized by EPR Signal II f SB 12 N -dodecyl- N , N -dimethyl-3-ammonio-1-propanesulfonate Mops 4-morpholinepropanesulphonic acid Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid

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LIPID-DEPENDENT DIffERENTIAL-EffECTS Of STEREOISOMERS Of ANESTHETIC ALCOHOLS

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第1期898卷 90-96页

作者： fIRESTONE, LL JANOff, AS MILLER, KW MASSACHUSETTS GEN HOSP DEPT ANESTHESIA BOSTON MA 02114 USA HARVARD UNIV SCH MED DEPT ANESTHESIA BOSTON MA 02115 USA HARVARD UNIV SCH MED DEPT PHARMACOL BOSTON MA 02115 USA

The cis- and trans-alkenols are equally potent general anesthetics but, respectively, lower and raise the gel-to-liquid crystalline phase transition temperature of saturated phosphatidylcholines (Pringle, M.J. and Miller, K.W. (1978) Biochem. Biophys, Res. Commun. 85, 1191-1198). Here we show that although this differential effect is somewhat reduced when a double bond is introduced into the sn-2 position of phosphatidylcholine, it is abolished when the ethanolamine head group is substituted for the choline head group in dimyristoyl lipids at neutral pH. At high pH, however, dimyristoylphosphatidylethanolamine assumes a negative charge, and its phase transition temperature drops to a value close to that for the corresponding phosphatidylcholine. Under these conditions the differential effect of the alkenol isomers is restored: the cis-alkenol lowers, while the trans-alkenol raises, the phase transition temperature of deprotonated dimyristoylphosphatidylethanolamine. Thus, the differential effects of cis- and trans-alkenols on the gel-to-liquid crystalline phase transition are dependent on the physical chemical characteristics of the polar region of the perturbed lipid species, but only weakly on that of the acyl region.

关键词： Phase transition pH Dimyristoylphosphatidylethanolamine Anesthesia Tetradecenol DMPC, 1,2-dimyristoyl- sn -glycero-3-phosphocholine DMPE, 1,2-dimyristoyl- sn -glycero-3-phosphoethanolamine DPPC, 1,2-dipalmitoyl- sn -glycero-3-phosphocholine DPPE, 1,2-dipalmitoyl- sn -glycero-3-phosphoethanolamine DSPC, 1,2-distearoyl- sn -glycero-3-phosphocholine SOPC, 1-stearoyl-2-oleoyl- sn -glycero-3-phosphocholine ESR, electron spin resonance f , spectroscopic solubility parameter Hepes, 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid T m , temperature of gel to liquid-crystalline phase transition Tempo, 2,2,6,6-tetramethylpiperidine-1-oxyl TLC, thin-layer chromatography W 1 2 , mean half-width of main transition

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MODIfICATION Of ROOM-TEMPERATURE PICOSECOND CHLOROPHYLL fLUORESCENCE KINETICS IN PHOTOSYSTEM-II ENRICHED PARTICLES BY PHOTOCHEMISTRY

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第1期892卷 42-47页

作者： HODGES, M MOYA, I Laboratoire de Photosynthèse C.N.R.S. Gif-sur-Yvette France

Room-temperature single photo timing measurements on Photosystem-II (PS II-) enriched thylakoid fragments at low excitation energies indicate the presence of three kinetic decay components of chlorophyll fluorescence arising from PS-II-associated pigments. Closing the PS II reaction centres produced three variable components, with lifetime values of 0.02-0.25, 0.15-0.90 and 0.35-2.0 ns, between the initial (fO) and maximal (fm) fluorescence levels. The yield of each component paralleled the changes in their respective lifetimes, indicating the presence of well-connected PS II reaction centres favouring energy transfer between each other. These changes show that variable chlorophyll fluorescence (fv) does not arise from one specific origin. The extent of the modifications and the observed relationship between component lifetime and yield, on closing PS II reaction centres, cannot be explained by either the delayed fluorescence (charge recombination) hypothesis of Klimov and co-workers (Klimov, V.V. et al. (1978) Dokl. Akad. Nauk. SSSR 242, 1204-1207) or the proposed changes and origins put forward by Holzwarth and co-workers (Holzwarth, A.R. (1986) Photochem. Photobiol. 43, 707-725;Holzwarth, A.R. et al. (1985) Biochim. Biophys. Acta 807, 155-167).

关键词： Photon counting Chlorophyll fluorescence lifetime Photosynthesis Charge recombination Photosystem II Chl chlorophyll PS Photosystem LHC light-harvesting Chl a b protein complex Q A primary stable electron acceptor of PS II Mes 4-morpholineethanesulphonic acid f m maximum chlorophyll fluorescence f 0 minimum chlorophyll fluorescence f v variable chlorophyll fluorescence

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STOICHIOMETRIES AND ENERGETICS Of PROTON TRANSLOCATION COUPLED TO ELECTRON-TRANSPORT IN CHLOROPLASTS

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第1期890卷 106-115页

作者： HANGARTER, RP JONES, RW ORT, DR WHITMARSH, J UNIV ILLINOIS USDA ARSDEPT PLANT BIOL289 MORRILL HALL 505 S GOODWIN AVE URBANA IL 61801 USA

We have investigated the stoichiometry of electron transport-driven proton uptake from the external medium and proton release into thylakoid vesicles of chloroplasts during single-turnover flash illumination. Proton uptake from the external medium was measured using a glass pH-electrode. for each electron originating from the oxidation of water by Photosystem II and ultimately forming H2O2 via the photoreduction of methyl viologen, approx. 2.7 proteons were taken up from the external medium. for each electron originating from the oxidation of duroquinol by the cytochrme b/f complex and ultimately forming H2O2 via methyl viologen under conditions in which water oxidation was inhibited by diuron, approx. 1.7 protons were taken up from the external medium. It is presumed that for each electron involved in the formation of H2O2 that one protein is taken up. Therefore, these results indicate that the electron-transfer reaction from H2O to Photosystem I involves the uptake of approx. 1.7 protons per electron, and that in the reaction from duroquinol to Photosystem I approx. 0.7 protons per electron are taken up. Proton release within the thylakoid vesicles was measured spectrophotometrically using the pH-sensitive dye neutral red. flash-induced absorbance changes due to neutral red indicated that for each proton released within the thylakoid vesicle due to water oxidation approx. 1.9 protons appear inside the vesicle as a result of quinol oxidation. The flash-induced formation of ATP was determined by the incorporation of 32Pi into ATP. The initiation of flash-induced ATP formation by Photosystem II operating alone required nearly twice as many flashes as were necessary when the Photosystem I-dependent turnover of the cytochrome b/f complex was responsible for proton accumulation, and nearly three times more than when Photosystem II and the cytochrome b/f complex operated together. This is taken to indicate that both of the reactions that result in proton accumulation wit

关键词： Proton translocation Electron transport Cytochrome b f complex Photosystem II Thylakoid vesicle Chl chlorophyll Cyt cytochrome DBMIB 2,5-dibromo-3-methyl-6-isopropyl- p -benzoquinone DCMU 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea DMQ 2,5-dimethylquinone DQH 2 duroquinol fCCP carbonylcyanide p -trifluoromethoxyphenylhydrazone feCN ferricyanide Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid Mes 4-morpholineethanesulfonic acid P i inorganic phosphate P-700 the primary donor of Photosystem I PS I Photosystem I PS II Photosystem II

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MODE Of INHIBITION Of SODIUM-AZIDE ON H+-ATPASE Of ESCHERICHIA-COLI

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fEBS LETTERS 1987年第2期213卷 381-384页

作者： NOUMI, T MAEDA, M fUTAI, M Department of Organic Chemistry and Biochemistry The Institute of Scientific and Industrial Research Osaka University Ibaraki Osaka 567 Japan

Sodium azide inhibited multi-site (steady-state) ATPase activity of E. coli f1 more than 90%, but did not affect uni-site (single-site) ATPase activity. Thus azide inhibited multi-site ATPase activity by lowering catalytic cooperativity. Consistent with this observation, azide changed the ligand-induced fluorescence response of aurovertin bound to f1.

关键词： H + -ATPase f 1 Uni-site catalysis Multi-site catalysis Sodium azide ( E. Coli ) p i , inorganic phosphate 32 P i , radioactive inorganic phosphate

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THE CLINICAL RELEVANCE Of MECHANICAL-PROPERTIES Of ELASTOMERS

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DENTAL MATERIALS 1987年第5期3卷 270-274页

作者： PAMENIUS, M OHLSON, NG Department of Dental Materials and Technology School of Dentistry The Karolinska Institute Box 4064 S-141 04 Huddinge Sweden

The removal of impression material from the patients's mouth is analyzed by use of the work required for separation. It is shown that this work is divided into several terms which may be elevated from the force-displacement curve by means of theory of elasticity. Experiments were made on 3 elastomers in a tensile testing machine. Authors propose that the work registered estimates the clinical feeling experienced. The adhesive strength between tooth and elastomer is derived as well.

关键词： elastomers dental impression material dental stress analysis mechanical stress photoelasticity Nomenclature W Total work W 1 = Work under peak (part one of curve) W 2 = Work under part two of curve W A = Work done against atmospheric pressure W S = Elastic work in shear against adhesion W f = Work done against friction W U = Elastic work for overcoming the undercut P A = atmospheric pressure A′= projected area of prepared tooth A 0 = area of the envelope surface of the undercut f= total tensile force f A = force due to p A 1 = peak force of part one of curve 2 = Maximum force of part two of curve d= displacement at peak force d′= total displacement during part one of curve τ 0 = interface shear stress at peak force E= Young's modulus G= shear modulus ν= Poisson's ratio μ= coefficient of friction (Ref. 3.)

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GROWTH-KINETICS AND DETERMINATION Of SHAPE AND SIZE Of SMALL AND LARGE AVOCADO fRUITS CULTIVAR HASS ON THE TREE

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SCIENTIA HORTICULTURAE 1987年第3-4期32卷 195-202页

作者： ZILKAH, S KLEIN, I Institute of Horticulture Agricultural Research Organization The Volcani Center Bet Dagan Israel

The shape and size of detached avocado fruit (Persea americana cultivar ''Hass'') were analysed throughout the growing season. formulae and procedures developed from this analysis were used to calculate growth kinetics of small and large fruits on the tree. The spatial shape factor (M) of the fruit was calculated from the volume ratios of the sampled fruit and its circumferential cylinder. This spatial shape factor of the fruit remained almost constant throughout all the stages of fruit growth, including the early one, when fruit length increased relatively more than fruit diameter. The growth of small and large fruits expressed on a logarithmic scale was found to be in close fit (coefficient of determination R2=0.99) to the hyperbolic function Y=(A+B)/X. Extrapolation of the growth curves indicated a few days difference in set of the small large fruits. The small and the large fruits were different in shape as well as in growth kinetics. The length/diameter (L/D) ratio of both large and small fruits increased gradually and reached an ultimate stationary level which was higher for the large fruits than for the small fruits.

关键词： avocado fruit shape fruit size growth kinetics Persea americana cultivar ‘Hass’ L fruit length D 1 fruit diameter measured between the maximally distant points on an imaginary plane which could be constructed by joining the stylar point and either the proximal or the distal ends of the stem D 2 fruit diameter measured perpendicular to D 1 R radius W fruit weight V f fruit volume V c circumferential cylinder volume of the fruit

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STEROID 21-HYDROXYLATION BY HUMAN PREOVULATORY fOLLICLES fROM STIMULATED CYCLES - A MASS-SPECTROMETRIC STUDY Of DEOXYCORTICOSTERONE, 21-HYDROXYPREGNENOLONE AND 11-DEOXYCORTISOL IN fOLLICULAR-fLUID

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JOURNAL Of STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY 1987年第3期26卷 337-343页

作者： DEHENNIN, L NAHOUL, K SCHOLLER, R FDN RECH HORMONOL 67-77 PASTEUR BLVD F-94260 FRESNES FRANCE

A highly specific technique based on gas chromatography-mass spectrometry associated with stable isotope dilution was applied to the analysis of follicular fluid aspirated from preovulatory follicles of women under ovarian stimulation prior to in vitro fertilization. Deoxycorticosterone, 21-hydroxypregnenolone and 11-deoxycortisol have been identified and quantified in the nanomolar concentration range. Significant positive correlations were found between these 21-hydroxy-steroids and their immediate precursors, thus indicating a probable common cellular origin. Corticosterone was tentatively identified and cortisol was evidenced at concentrations lower than peripheral plasma levels. The occurrence in human follicular fluid of cortisol, together with different high concentration intermediates, constitutes evidence for ovarian intra-follicular 21-hydroxylase activity, and probably slso for ***.-hydroxylation enzyme activity.

关键词： ff follicular fluid GC-MS gas chromatography-mass spectrometry M + molecular ion m / z mass-to-charge ratio MO-TMS O -methyloxime-trimethylsilyl ether EO-TMS O -ethyloxime-trimethylsilyl ether t BDMS t -butyldimethylsilyl ether PfP pentafluoropropionate HfB heptafluorobutyrate P progesterone 5P preg-nenolone 5P 3β-hydroxy-5-pregen-20-one 5PS pregneno-lone sulfate 5PS 3β-hydroxy-5-pregnen-20-one 3-sulfate 170HP 17-hydroxyprogesterone 170HP 17α-hydroxy-4-pregene-3,20-dione DOC deoxycorticosterone deoxycorticosterone 21-hydroxy-4-pregnene-3,20-dione 210HPr 21-hydroxy-pregnenolone 21-hydroxy-pregnenolone 3β,21-dihydroxy-5-pregnen-20-one 210HPrS 21-hydroxypregnenolone sulfate 21-hydroxypregnenolone sulfate 3β,21-dihydroxy-5-pregnen-20-one 3-sulfate S 11-deoxy-cortisol 11-deoxy-cortisol 17,21-dihydroxy-4-pregnene-3,20-dione B cor-ticosterone cor-ticosterone 11β,21-dihydroxy-4-pregnene-3,20-dione f cortisol cortisol 11β,17α,21-trihydroxy-4-pregnene-3,20-dione E 2 estradiol-17β hMG human menopausal gonad-otrophin SEM standard error of the mean

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CONNECTED AND DISCONNECTED fIELDS

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TOPOLOGY AND ITS APPLICATIONS 1987年第1期27卷 37-50页

作者： SHELL, N CUNY CITY COLL DEPT MATHNEW YORKNY 10031

Examples are sought of Hausdorff ring topologies on a field that are (i) arcwise connected; (ii) connected but not arcwise connected; (iii) totally disconnected but not ultraregular; (iv) ultraregular but not basically disconnected; (v) basically disconnected but neither a P -space nor extremally disconnected; (vi) P -spaces; (vii) extremally disconnected. Examples of type (i), (ii), (iv) and (vi) are given. for a field with a ring topology, properties of f -zerosets are considered. In particular, it is shown that the intersection of each pair of f -zerosets is again an f -zeroset if and only if {(0, 0)} is an f -zeroset of f 2 .

关键词： Primary 12J99 secondary 54C20, 54C40 arcwise connected field f -zeroset comparable connected ring topologies maximum ring topology extremally disconnected field P -space field

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INfLUENCE Of THE REDOX STATE AND THE ACTIVATION Of THE CHLOROPLAST ATP SYNTHASE ON PROTON-TRANSPORT-COUPLED ATP SYNTHESIS HYDROLYSIS

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第2期893卷 275-288页

作者： JUNESCH, U GRABER, P TECH UNIV BERLIN MAX VOLMER INST BIOPHYS & PHYS CHEM STR 17 JUNI 135 D-1000 BERLIN 12 FED REP GER

The membrane-bound ATP synthase from chloroplasts can occur in different redox and activation states. In the absence of reductants the enzyme usually is oxidized and inactive, Eiox. Illumination in the presence of dithiothreitol leads to an active, reduced enzyme, Eared. If this form is stored in the dark in the presence of dithiothreitol an inactive, reduced enzyme Eired is formed. The rates of ATP synthesis and ATP hydrolysis catalyzed by the different enzyme species are measured as a function of .*** (.DELTA..psi. = 0 mV). The .*** was generated with an acid-base transition using a rapid-mixing quenched flow apparatus. The following results were obtained. (1) The oxidized ATP synthase catalyzes high rates of ATP synthesis, vmaxox = 400 ATP per Cf0f1 per s. The half-maximal rate is obtained at .*** = 3.4. (2) The active, reduced ATP synthase catalyzes high rates of ATP synthesis, Vmaxred = 400 ATP per Cf0f1 per s. The half-maximal rate is obtained at .*** = 2.7. It catalyzes also high rates of ATP hydrolysis vmaxred = -90 ATP per Cf0f per s at .*** = 0. (3) The inactive species (both oxidized and reduced) catalyze neither ATP synthesis nor ATP hydrolysis. The activation/inactivation of the reduced enzyme is completely reversible. (4) The activation of the reduced, inactive enzyme is measured as a function of .*** by measuring the rate of ATP hydrolysis catalyzed by the active species. Half-maximal activation is observed at .*** = 2.2. (5) On the basis of these results a reaction scheme is proposed relating the redox reaction, the activation and the catalytic reaction of the chloroplast ATP synthase.

关键词： ATP synthesis ATP hydrolysis Cf 0 f 1 activation Redox-state Membrane Energization Chloroplast Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine Cf 0 f 1 proton-translocating ATP synthase from chloroplasts P i inorganic phosphate Chl chlorophyll DCMU 3-(3,4-dichlorophenyl)-1,1 dimethylurea

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