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EVIDENCE fOR AMINO ACID-H+ COTRANSPORT IN LEMNA-GIBBA GIVEN BY EffECTS Of fUSICOCCIN

ZEITSCHRIfT fUR PfLANZENPHYSIOLOGIE 1981年第2期102卷 117-125页

作者： LUTTGE, U JUNG, KD ULLRICHEBERIUS, CI Institut für Botanik der Technischen Hochschule Darmstadt Schnittspahnstraße 3 D-6100 Darmstadt FRG

The fungal toxin fusicoccin (fC, 0.015–0.03 mol m -3 ) considerably hyperpolarizes the membrane of energy deficient Lemna gibba plants where Δψ initially is low, and to a lesser extent the higher Δψ of non-deficient plants. In both cases similar Δψ values are attained in the presence of fC. L-alanine uptake is enhanced by fC in relation to the fC-induced increase of Δψ, i. e., the effect is larger in deficient plants than in non-deficient ones. fC does not significantly affect the substrate constant (K S ) of amino acid uptake by Lemna . It decreases the amplitude of L-alanine triggered transient membrane depolarizations and inhibits repolarization in the presence of L-alanine. fC effects on membranes are not readily reversible by washing fC-treated plants with fC-free medium. It is known from the literature that fC is a specific stimulatory effector of an ATPase in the plasmalemma of higher plants, which actively extrudes protons. Therefore, the present results allow the conclusion that electrogenicity in Lemna is due to active H + extrusion. The proton pump of Lemna binds fC rather tightly and works near its maximum possible rate in the presence of fC. The H + -electrochemical gradient established by the pump drives amino acid uptake via cotransport with H + .

关键词： Lemna gibba fusicoccin amino acid transport C amino-acid carrier P proton pump ABA abscisic acid fC fusicoccin Δψ electrical membrane potential Δ µ ˜ H + electrochemical proton gradient R universal gas constant f faraday T absolute temperature

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INCORPORATION Of ISOPENTENYLDIPHOSPHATE-1-C-14, GERANIOL AND fARNESOL INTO CHLOROPHYLL IN PLASTID MEMBRANE-fRACTIONS Of AVENA-SATIVA L

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ZEITSCHRIfT fUR PfLANZENPHYSIOLOGIE 1981年第2期102卷 95-100页

作者： BENZ, J RUDIGER, W UNIV MUNICH INST BOT D-8000 MUNICH 19 FED REP GER

Incorporation of 1-14C -isopentenyldiphosphate (IPP) and related diprenyl and triprenyl substrates into chlorophyll of irradiated etioplast membranes of A. sativa L. was investigated. The etioplast membranes contain the enzyme chlorophyll synthetase which catalyzes the esterification of chlorophyllide with exogenous substrates like geranylgeranyl diphosphate or geranylgeraniol + ATP. The main product after incubation with IPP, IPP + geraniol/ATP, IPP + farnesol/ATP or IPP + farnesyl diphosphate was chlorophyll containing geranylgeraniol (ChlGG), followed by chlorophyll containing dihydrogeranylgeraniol (ChlH2GG), chlorophyll containing tetrahydrogeranylgeraniol (ChlH4GG) and chlorophyll containing phytol (ChlP). Increased yields of ChlP after incubation with farnesyl diphosphate with or without IPP were due to increased mobilization of endogenous substrates. The specific radioactivities of ChlGG after incubation with IPP + farnesol, IPP + geraniol or IPP alone indicated the incorporation of 1, 2 or 3 mol IPP, respectively, into 1 mol geranylgeraniol. Specific radioactivities of ChlH2GG were somewhat, and those of ChlH4GG and ChlP considerably, smaller than that of ChlGG. The results confirmed earlier observations on the following sequential steps for chlorophyll biosynthesis: Chlide .fwdarw. ChlGG .fwdarw. ChlH2GG .fwdarw. ChlH4GG .fwdarw. ChlP.

关键词： Avena sativa etioplasts chlorophyll synthetase prenyl transferase chlorophyllide a chlorophyll a geranylgeraniol phytol IPP isopentenyl diphosphate Chlide chlorophyllide a Chl GG , Chl H 2 GG , Chl H 4 GG , Chl p Chl f esterified chlorophyll a containing geranylgeraniol, dihydrogeranylgeraniol, tetrahydrogeranylgeraniol, phytol, or farnesol, respectively

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EffECT Of ATP ON THE TRANSLATIONAL DIffUSION-COEffICIENT Of THE ALPHA-SUBUNIT Of ESCHERICHIA-COLI f1-ATPASE

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fEBS LETTERS 1980年第2期120卷 289-292页

作者： PARADIES, HH Fachrichtung Biochemie der Pflanzen Freie Universität Berlin Königin-Luise-Str. 12-16a D-1000 Berlin 33 Germany

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IDENTIfICATION Of AN INTRAMOLECULAR CROSS-LINK IN TROPONIN-C AfTER CROSS-LINKING THE TROPONIN COMPLEX WITH 1,3-DIfLUORO-4,6-DINITROBENZENE

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第2期625卷 304-309页

作者： GUSEV, NB SAJGO, M fRIEDRICH, P HUNGARIAN ACAD SCI BIOL RES CTR INST ENZYMOL POB 7 H-1502 BUDAPEST HUNGARY

The troponin complex isolated from rabbit skeletal muscle was cross-linked with 1,3-difluoro-4,6-dinitrobenzene, subjected to tryptic hydrolysis, and the labeled peptides were separated. One peptide was purified to homogeneity;it was peptide Gly(89)-Arg(100) of troponin C on the basis of amino acid composition and N-terminal analysis. The absorption spectrum of this peptide between 300 and 500 nm was very similar to that of 1-(S-cysteinyl)-5-(***.-lysyl)-2,4-dinitrobenzene, which could only be due to cross-link formation between Lys-90 and Cys-98. This finding is interpreted in terms of the proposed tertiary structure of troponin C.

关键词： Troponin C cross-linking Side-chain topology Peptide analysis Difluorodinitrobenzene f 2 DNB 1,3-difluoro-4,6-dinitrobenzene EGTA ethylene glycol bis( β -aminoethyl ether)- N , N , N ′, N ′-tetraacetic acid

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LOCATION Of THE AROMATIC BINDING-SITE AND PREPARATION Of AN AROMATIC DERIVATIVE Of GLYCOGEN-PHOSPHORYLASE

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第2期613卷 370-380页

作者： THOMAS, TP PHILIP, G UNIV COCHIN DEPT MARINE SCI COCHIN 682016 INDIA

Rabbit muscle glycogen phosphorylase b (EC 2.4.1.1) was inactivated by 1,5-difluoro-2,4-dinitrobenzene at pH 7.6 at a rate much faster than by 1-fluoro-2,4-dinitrobenzene. The reaction was very specific at low concentration of 1,5-difluoro-2,4-dinitrobenzene. Glucose-1-phosphate, G-6-P, AMP and ATP afforded protection against inactivation by 1,5-difluoro-2,4-dinitrobenzene. These results and kinetic analyses of the modified enzyme were used to locate the binding site for aromatic compounds in phosphorylase. The above ligands and aromatic compounds bound on the enzyme in the same region which is located near the monomer/monomer interface. An apparently homogeneous dinitrodiphenylene derivative of phosphorylase b with only 1 group/dimeric enzyme and having 50% of the catalytic activity was prepared. This derivative, in which the subunits were not crosslinked by the reagent, was devoid of the homotropic cooperativity for the substrate or activator sites even in the presence of allosteric inhibitors. Glucose behaved quite differently from other ligands in its effect on modification and on the kinetics of the modified enzyme. The significance of the glucose site is discussed.

关键词： Aromatic binding site Glycogen phosphorylase Chemical modification f 2 DNB 1,5-difluoro-2,4-dinitrobenzene fDNB 1-fluoro-2,4-dinitrobenzene

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CA-2+-INDUCED CONfORMATIONAL-CHANGES IN THE TROPONIN COMPLEX DETECTED BY CROSSLINKING

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期626卷 106-116页

作者： GUSEV, NB fRIEDRICH, P HUNGARIAN ACAD SCI BIOL RES CTR INST ENZYMOL H-1502 BUDAPEST HUNGARY

To detect Ca2+-induced conformational changes by crosslinking, rabbbit muscle troponin complex was reacted with the bifunctional reagents 1,3-difluoro-4,6-dinitrobenzene, 4,4''-difluoro-3,3''-dinitrodiphenylsulfone and dimethyl suberimidate under various conditions and the products were analyzed by dodecyl sulfate gel electrophoresis. In the absence of divalent cations, with the 2 aromatic reagents at a low reagent:protein ratio, the main crosslink products were troponin T-I and I-C. With dimethyl suberimidate, the only major crosslink product was conjugate T-I. Ca2+, alone and in the presence of Mg2+, prevented the formation of I-C crosslinks with both aromatic reagents. It did not affect crosslinking with dimethyl suberimidate. Ca2+ decreased the number of NH2 groups of troponin that are highly reactive towards 2,4,6-trinitrobenzene sulfonate. Both effects of Ca2+ can be interpreted in terms of a conformational change in the troponin complex elicited by the binding of the specific divalent cation.

关键词： Troponin complex Crosslinking Ca 2+ binding Conformational change Amino group reactivity EGTA ethyleneglycol-bis(β-aminoethylether)- N,N,N ′, N ′-tetraacetic acid f 2 DB 1,3-difluoro-4,6-dinitrobenzene f 2 DPS 4,4′-difluoro-3,3′-dinitrodiphenylsulfone SDS sodium dodecyl sulfate TNBS 2,4,6-trinitrobenzenesulfonate

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fORMATION Of EXCITED-STATES BY ION IMPACT ON SURfACES

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PROGRESS IN SURfACE SCIENCE 1980年第4期10卷 383-489页

作者： THOMAS, EW GEORGIA INST TECHNOL SCH PHYSATLANTAGA 30332

Impact of energetic ions on surfaces gives rise to a variety of excited states in the sputtered particles, in the reflected projectiles and sometimes of molecular species bound to the surface. Where the outer shell of the system is excited the state will normally decay with emission of optical photons that may be detected with conventional spectroscopy. Where there are vacancies in the inner shells the species may be detected by subsequent emission of Auger electrons or x-rays. The review provides a comprehensive catalogue of the available data and attempts to correlate the various observations. Optical emissions from sputtered and recoil particles are strongly influenced by radiationless de-excitation processes and this is incorporated into models that describe both line shape and line intensity. There is, however, no well developed description of how the excited states are formed. Thermal excitation models that describe excitation in terms of a Local Thermodynamic Equilibrium plasma are shown to be poorly founded. Alternative models ascribing excitation to bi-particle collision events have not yet been quantitatively tested. Inner shell excitation certainly appears to be governed by electron promotion events in the transient quasi-molecule formed by a projectile and target atom. We review briefly the possible applications of ion induced optical emission to the analysis of surface composition.

关键词： AES Auger Electron Spectroscopy BEA Binding Energy Approximation IBSCA Ion Beam Spectrochemical Analysis LTE Local Thermodynamic Equilibrium SCANIIR Surface Composition Analysis By Neutral and Ion Impact Radiation SIMS Secondary Ion Mass Spectroscopy S/I Normalized Stokes Parameter (Difference between right and left hand circularly polarized intensities divided by the sum of these two intensities) f

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COMPONENTS AND ACTIVITY Of THE PHOTOSYNTHETIC ELECTRON-TRANSPORT SYSTEM Of INTACT HETEROCYSTS ISOLATED fROM THE BLUE-GREEN-ALGA NOSTOC-MUSCORUM

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期592卷 113-120页

作者： ALMON, H BOHME, H Lehrstuhl für Physiologie und Biochemie der Pflanzen Universität Konstanz D-7750 Konstanz F.R.G.

Heterocysts of the blue-green alga N. muscorum were isolated by prolonged treatment with lysozyme. Quantitative data are presented which show the occurrence of cytochromes c-553, f-557 and b-563 in heterocysts in amounts comparable to vegetative cells. Particularly the content of the water-soluble cytochrome c-553 can be used to evaluate the intactness of a heterocyst preparation. Cytochrome f-557 has been partially purified and found to be a c-type cytochrome corresponding to cytochrome f of higher plants and other algae. Cytochrome b-559 is present in vegetative cells but not in heterocysts. The content of plastoquinone in heterocysts is reduced to 42% of the amount present in vegetative cells. These data suggest a degradation of photosystem II during heterocyst differentiation. Measurements of photosynthetic electron transport in heterocysts proved the inability of the photosynthetic apparatus to carry out electron transport with electrons donated by water or diphenylcarbazide. In Tris-washed thylakoids from vegetative cells, however, diphenylcarbazide can act as an electron donor to photosystem II.

关键词： Heterocyst Photosynthesis Redox carrier Cytochrome f -557 Electron transport Photosystem II (Nostoc muscorum) DCMU N -(3,4-dichlorophenyl)- N ′, N ′-dimethylurea Hepes N -2-hydroxyethylpiperazine- N ′-2-ethanesulfonic acid Tricine N -tris(hydroxymethyl)-methylglycine Chl chlorophyll

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PROTEOLYSIS Of SKELETAL-MUSCLE ADENYLATE-CYCLASE - DESTRUCTION AND RECONSTITUTION Of fLUORIDE AND GUANYLNUCLEOTIDE SENSITIVITY

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第3期631卷 393-401页

作者： DRUMMOND, GI NAMBI, P UNIV CALGARY DEPT CHEM BIOCHEM UNIT CALGARY T2N 1N4 ALBERTA CANADA

Adenylate cyclase was measured in skeletal muscle plasma membranes incubated with subtilisin. Under specific conditions the protease preferentially inactivated fluoride and guanylnucleotide sensitivity. following protease treatment, membranes were solubilized with Lubrol 12A9 and subjected to ion-exchange chromatography. Adenylate cyclase was eluted with 200 mM NaCl;the enzyme recovered was unresponsive to Naf or guanylyl imidodiphosphate. Responsiveness to the 2 ligands was restored by adding a heart fraction in which basal activity had been destroyed by heating at ***. C or by adding a soluble skeletal muscle fraction in which basal activity had been destroyed by N-ethylmaleimide. The solubilized subtilisin-treated skeletal muscle preparation may serve as a source of catalytic activity for the study and purification of regulatory factors for adenylate cyclase.

关键词： Adenylate cyclase f − sensitivity Proteolysis Guanylnucleotide (Skeletal muscle) Gpp(NH)p guanyl-5′-yl imidodiphosphate

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PLANT INHIBITORS Of SERINE PROTEINASES - HAGEMAN-fACTOR fRAGMENT, KALLIKREINS, PLASMIN, THROMBIN, fACTOR-XA, TRYPSIN, AND CHYMOTRYPSIN

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THROMBOSIS RESEARCH 1980年第2期20卷 163-171页

作者： HOJIMA, Y PIERCE, JV PISANO, JJ Section on Physiological Chemistry Laboratory of Chemistry National Heart Lung and Blood Institute Bethesda Maryland 20205 U.S.A.

Numerous plants were tested for ihibitors of human Hageman factor fragment (Hff), plasma kallikrein, urinary kallikrein, plasmin, thrombin, porcine pancreatic kallikrein and bovine factor Xa, trypsin, and chymotrypsin. Pumpkin seeds and iris bulbs contain trypsin inhibitors which specifically inhibit Hff. flower *** those of tulip, lily, hyacinth, and *** unrecognized rich sources of inhibitors with different inhibitory spectrums and physicochemical properties.

关键词： Hageman factor fragment inhibitor kallikrein inhibitor trypsin inhibitor Hf f Hageman factor fragment TAME N α -tosyl-L-arginine methyl ester BTEE N-benzoyl-L-tyrosine ethyl ester IU inhibitor unit M r molecular weight

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