bluuebunny/crossref_metadata_2025 huggingface dataset:
Herbicides which Inhibit Electron Transport or Produce Chlorosis and Their Effect on Chloroplast Development in Radish Seedlings II. Pigment Excitation, Chlorophyll Fluorescence and Pigment-Protein Complexes
Authors: Buschmann C. , Grumbach K. H.
Published: August 2018

DCMU, bentazon, amitrole and SAN 6706 affected the formation of the pigment-protein complexes and caused drastic alterations in the absorption of light and in the transfer of the absorbed energy in the antennae systems. Bentazon and DCMU, photosystem II inhibitors, did not change the pigment absorption and fluorescence excitation spectra. After application of both herbicides the long wavelength fluorescence emission band at 740 nm was reduced similar as in young developing leaves. Although DCMU and bentazon inhibit the photosynthetic electron transport at the same site, bentazon mainly suppressed the formation of the photosystem I complexes CP 1 a and CP 1 while DCMU mainly reduced the photosystem II complex CPa. Bentazon specifically enhanced the formation of LHCP3. This may be important for the increased grana stacking in plastids from bentazon treated plants.

The bleaching herbicides amitrole and SAN 6706 inhibited the formation of carotenoids leading to an accumulation of lycopene, phytofluene and phytoene, while the accumulation of chlorophylls was suppressed. This bleaching effect was most pronounced during growth under higher intensities of light. In weak light (100 lux) amitrole reduced the long wavelength fluorescence maximum but the fluorescence excitation was not affected. With amitrole at 2000 lux and SAN 6706 at 100 lux the long wavelength emission band was further decreased and the fluorescence excitation spectra point to a less efficient energy transfer to chlorophyll a. The fluorescence spectra changed due to herbicide treatment resembled those of not yet fully developed leaves. In contrast to the photosystem II herbicides the bleaching herbicides amitrole and SAN 6706 had a similar effect on the formation of pigment-protein complexes. After growth at 2000 lux both herbicides suppressed the formation of the photosystem I complex CP 1 a and the photosystem II complex CPa. At 100 lux only the formation of CPla was affected.

Except for DCMU all herbicides assayed primarily changed the formation of photosystem I.
Ellagitannine aus den Blättern von Vitis vinifera / Ellagitannins from the Leaves of Vitis vinifera
Authors: Karl Christian , Müller Gerhard , Pedersen Peter Alsted
Published: August 2018

From methanolic extracts of dried leaves of Vitis vinifera 3 ellagitannins were isolated: brevilagin 1, 1,3-digalloyl-4,6-dehydrohexahydroxydiphenoylglucose (=vitilagin), 3,4-digalloyl-1,6-de- hydrohexahydroxydiphenoylglucose (= iso-vitilagin).
Isoelectric Focusing of the NAD(P)H-Cytochrome c Reductase Subunit of Chlamydomonas reinhardii Nitrate Reductase
Authors: Fernández Emilio , Cárdenas Jacobo
Published: August 2018

Chlamydomonas reinhardii 104 mutant strain cells contain many NAD(P)H-cytochrome c reductase activities unrelated to nitrate reduction in addition to an NAD(P)H-cytochrome c reductase related to NAD(P)H-nitrate reductase, which have molecular weights from 37000 to 124000. By combining chromatographic procedures and preparative isoelectric focusing, three major fractions of NAD(P)H-cytochrome c reductase were isolated with pi at 7.1, 5.5 and 5.05, respectively. Of these fractions, only the last one was identified as the diaphorase subunit of the NAD(P)H-nitrate reductase by its ability to reconstitute in vitro the nitrate reductase native complex upon complementation with active terminal nitrate reductase of 305 mutant of C. reinhardii.
Oxygen-Evolving Extracts from a Thermophilic Cyanobacterium Synechococcus sp.
Authors: Miyairi Sachio , Schatz Günther H.
Published: August 2018

Spheroplast membranes of a thermophilic cyanobacterium Synechococcus sp. have been treated with the detergent lauryldim ethylam ine oxide (LDAO). The resulting extracts show (1) light-induced O2 evolution with artificial electron acceptors, (2) four-fold enhancement of the O2 evolution relative to chlorophyll, (3) parallel increase of both the molar ratios of PS 2/C hl and cyt b559/Chl in the extract, (4) dissociation of the auxiliary pigment phycocyanin upon treatment with LDAO, but still tight association of allophycocyanin to the photosystem 2 preparation.
Long Term Cultures of Neural Retina and Pigment Epithelium from Newborn Rabbits
Authors: Tsukamoto Tetsuro , Ludwig Hanns
Published: August 2018

In vitro cultures of neural retina, obtained after dispersion and trypsinization of tissue frag ments, were composed of 3 morphologically distinct types o f neural cells, as demonstrated by sil­ver impregnation. They resem bled ganglion or receptor cells, horizontal or amacrine cells, and bi­polar cells of the intact retina. Pigment epithelium was cultured without trypsinization. Both kinds o f techniques may prove helpful for long term experiments in neurobiology and neurovirology.
Antimicrobial Activity of N,N'-bis(decylmethyl)- α,ω-alkanediamine Dioxides [1]
Authors: Devínsky Ferdinand , Lacko Ivan , Krasnec Ludovít , Mlynarčík Dušan
Published: August 2018

Antimicrobial activity of N,N′-bis(decylmethyl)-α,ω-alkanediamine dioxides determined on Staphylococcus aureus, Escherichia coli, and Candida albicans is presented as minimal inhibitory concentration (MIC). The effect of the length of linking alkylene chain on this activity has been followed.
On the Origin of the Non-Haemic Iron Transferrin ESR Signal: ESR Investigations on Histidine-Iron-Citric Acid Systems
Authors: Lohmann W. , Holz D. , Kiefer B. , Schmidt D.
Published: August 2018

The nature o f the high spin ferric iron complex located at g = 4.3 has been investigated by means of electron spin resonance spectroscopy and polarography. It could be shown that two complexes each exist in the acid and alkaline pH region, and that the iron is bound to two histidines, three citric acids, and probably to one bicarbonate. These results agree well with previous findings according to which the ligand field o f iron should be com posed mainly o f oxygen and nitrogen atoms. Another low-field signal located at g = 3.6 appears in the pH range from 2 to 7 only and exhibits its maximum where the g = 4.3 signal has its minimum . Its exact nature is still unknown but it seems to represent some intermediate state of the ternary Fe3+- histidine-citric acid complex. When citric acid is used, the spin concentration seems to be always larger than in the case of ascorbic acid. Since the effect obtained with ascorbic acid and citric acid seems to be similar, it may be concluded that the biological function of both of the acids might be somehow related to each other
15N-Coprobiliverdin, a New Model Chromophore
Authors: Köst Hans-Peter , Benedikt Eva , Cmiel Edmund , Schneider Siegfried
Published: August 2018

The synthesis of 15N-labeled coprobiliverdin III, a bile pigment with four conjugated pyrrole nuclei and four carboxylic acid side chains, is described. Coprobiliverdin is structurally characterized by chemical and various spectroscopic methods (e.g. chromic acid degradation, UV-vis-, IR-, mass spectroscopy). The results of 15N NMR studies reveal the potential value of this compound as a probe for structural interactions in biliproteins and as a reference for the future investigation of natural bile pigments deriving from coproheme
Circular Dichroism of Chromopeptides from Phycocyanin
Authors: Schamagl C. , Köst-Reyes E. , Schneider S. , Köst H.-P. , Scheer H.
Published: August 2018

The circular dichroism of bilipeptides from Spirulina geitleri phycocyanin is strongly solvent and pH dependent. Maximum optical activity has been observed in aqueous solutions containing urea (8 ᴍ). In aqueous buffer, a sign reversal occurred upon the change from neutral to acidic pH; in methanolic solutions shows the optical activity a strong pH dependence both with respect to sign and magnitude. These findings have been rationalized by the presence of chrom ophorepeptide interactions, which are minimized in the presence of urea. M olecular orbital calculations indicate that the observed sign reversal is not necessarily due to a reversal of the chirality of the entire chromophore, but may also result from more localized conform ational changes
Molecular Properties of High Potential Iron Sulfur Protein of Chromatium warmingii
Authors: Wermter Ursula , Fischer Ulrich
Published: August 2018

High potential iron sulfur protein (HIPIP) of the purple sulfur bacterium Chromatium warmingii was purified to homogeneity by ion exchange chromatography, gel filtration and ammonium sulfate fractionation. The acidic protein was isolated in the reduced form. The best purity index (A280/A388) obtained was 2.52, and 3.8 μmol of the protein was isolated out of 100 g wet cell material. The molecular weights estimated by sodium dodecylsulfate polyacrylamide gel electrophoresis and gel filtration through Sephacryl S-200 were 8 900 and 10 500, respec­tively. The protein has an isoelectric point at pH 3.6 for the reduced form and at pH 3.8 for the oxidized form, and a midpoint redox potential of +355 mV. One mol of HIPIP contains 4 mol nonheme iron and 4 mol acid-labile sulfur
A Conformational Transition of the Sarcoplasmic Reticulum Calcium Transport ATPase Induced by Vanadate
Authors: Hasselbach Wilhelm , Medda Pankaj , Migala Andrea , Agostini Bruno
Published: August 2018

Vanadate binding to sarcoplasmic reticulum vesicles results in the loss of the externally located high affinity calcium binding sites of the calcium transport ATPase. Conversely the occupation by calcium of the internally located low affinity sites in the vanadate enzyme complex leads to the release of vanadate. Since the total number of calcium binding sites is not diminished by vanadate binding but slightly increases we conclude that vanadate binding induces a transition of the enzymes external high to internal low affinity calcium binding sites. The transposition of external to internal calcium binding sites is accompanied by a definite change in the structure of the sarcoplasmic reticulum membranes. On vanadate binding the asymmetrically arranged electron dense protein particles become symmetrically distributed
Variation in cephalic volatile substances in relation to worker age and behavior in the stingless bee, scaptotrigona postica
Authors: Francke W. , Schröder W. , Engels E. , Engels W.
Published: August 2018

Head extracts of adult workers of the Brazilian stingless bee Scaptotrigona postica (Trigonini, Meliponinae: Apidae) were analysed for volatile substances by gas chrom atography/ mass spectroscopy. Individual worker bees performing clearly defined tasks and representing five age groups were collected. A total of 36 compounds was identified, 22 of which had not been previously described for a Trigona species.

The major components are 2-heptanol, 2-tridecanone, 2-pentadecanone, Z-5-tetradecenylbutanoate and Z-7-hexadecenylbutanoate. 11 of the 36 compounds increase in concentration with age, but only 2 decrease. The other substances are present in more or less constant concentrations. These data are discussed assuming more complicated pheromone-m ediated interactions within an age-dependent polyethism between old workers acting inside and outside the nest than between young house bees
Ein verbessertes verfahren zur isolierung und quantitativen bestimmung von vincaleukoblastin aus intakten pflanzen und gewebekulturen von catharanthus roseus g. don. / An im proved method of isolation and titative determination of vincaleucoblastine from intact plants and tissue cultures of catharanthus roseus g. don.
Authors: Hofmann W. , Kubeczka K.-H. , Czygan Franz-C.
Published: August 2018

Improved methods of extracting vincaleucoblastin from leaves and tissue cultures of Catharanthus

roseus and of the quantitative determination of this dimeric indole-alkaloid by reflectance densitometry of TLC-plates have been established. Approximately 0.05% VLB were found in the leaves and, using high-performance-thin-layer-chromatography, 0.00013% VLB in callus cultures (not in suspension cultures!) derived from this plant
Mechanisms of Inhibition by Mevinolin (MK 803) of Microsome- Bound Radish and of Partially Purified Yeast HMG-CoA Reductase (E C .l.1.1.34)
Authors: Bach Th. J. , Lichtenthaler H. K.
Published: August 2018

1) In kinetic studies, mevinolin proved to be a highly specific inhibitor of partially purified yeast HMG-CoA reductase (Ki = 3.5 nᴍ towards HMG-CoA) and of microsomal HMG-CoA reductase from etiolated radish seedlings (Ki = 2.2 nᴍ). At low concentrations of NADPH, the inhibitor counteracts the sigmoidal response of plant HMG-CoA reductase activity towards the cosubstrate. At higher concentrations of NADPH, the inhibition pattern is of non-competitive type.

2) Our results are extensively compared with that obtained by the use of animal tissue and yeast as an enzyme source in order to discuss model systems probably valid to evaluate properties and regulation of plant as well as yeast HMG-CoA reductase
L-Usnate-Urease Interactions: Binding Sites for Polymerization
Authors: Cifuentes B. , García I. , Vicente C.
Published: August 2018

ʟ-usnic acid inactivates urease through a process which implicates the blockade of - SH groups in parallel to the formation of inactive polymers. Both ʟ-alanine and ʟ-proline partially reverses the inactivation and effectively diminishes the amount of highly polymerized protein. The amino acids also prevent the linkage of ʟ-usnic acid on the sites of low affinity for the ligand, being then related to the sites of polymerization
Prostaglandin Synthesis Inhibitors Reduce Cannabis and Restraint Stress Induced Increase in Rat Brain Serotonin Concentrations
Authors: Bhattacharya S. K. , Bhattacharya D.
Published: August 2018

Cannabis resin (Cl) produced a dose-related increase in rat brain serotonin concentrations, whereas restraint stress produced maximal rise of the neurotransmitter concentrations at 1 h, followed by a tendency to normalise by 4 h. The prostaglandin (PG) synthesis inhibitors, diclofenac and paracetamol, antagonized Cl and restraint stress induced rise in serotonin concentrations. The findings lend credence to earlier reports that PG synthesis inhibitors antagonize serotonin-mediated neuropharmacological actions of Cl and restraint stress in rats
Geranyl Derivatives as Inhibitors of the Carotenogenesis in Synechococcus PCC 6911 (Cyanobacteria)
Authors: Jüttner Friedrich , Bogenschütz Ottmar
Published: August 2018

The ability of several geranyl derivatives to inhibit carotenoid synthesis in Synechococcus (Cyanobacteria) was measured using a cyanobacterial bioassay. The inhibitory activity of differ­ent molecules varied according to chain length and substituents. Pseudoionone, farnesyl acetate, geranyl acetate, geranial and farnesol proved to be the most active derivatives tested. 6-Methylhept-5-en-2-one, farnesyl acetone, linalool and geranyl linalool exhibited no effect when employed in concentrations as high as 100 ppm. Besides phytofluene, ζ-carotene was accumu­lated after application of sublethal amounts of active geranyl derivatives. Cell growth and chlorophyll a synthesis were only slightly affected under conditions were carotenoid synthesis was markedly inhibited.
Electromagnetic Modulation of Biological Processes: ATPase Function and DNA Production by Raji Cancer Cells in vitro
Authors: Colacicco Giuseppe , Pilla Arthur A.
Published: August 2018

Addition of either ATP or ouabain to the culture medium markedly depressed thymidine incorporation into DNA in Raji cells. The electromagnetic field, pulsating at very low frequency, did not affect DNA synthesis in normal culture media nor did it alter its ouabain-inhibition, but it partially reversed the ATP-inhibition. In spite of the presence of ATP, ouabain prevented stimulation of ATPase and DNA synthesis by the field. Although no mechanism is known for the action of either ATP or the field, the results may be interpreted in light of existing speculations. In the absence of the field, external ATP may go into an ATP pool that either blocks ATPase or feeds adenyl cyclase, which hinders DNA synthesis. In contrast, the electromagnetic field may either turn off adenyl cyclase or simply stimulate the ATP-depressed ATPase.
Crystal Packing of Odd-Chain Saturated Triglycerides
Authors: Dorset Douglas L.
Published: August 2018

Single crystal electron diffraction data from an odd-chain triglyceride, glycerol triheptadecanoate, are compared with the known structure of the even-chain homo-acid triglycerides. Both class­es of triglycerides are found to resemble one another in chain packing: they both have the same chain tilt (61 °) for the β-polymorph and, further, the orientation of the T∥ subcell in the crystal structure is identical. The existence of the T∥ subcell is quantitatively verified for the first time with the diffraction intensities from suitably tilted crystals. Given these similarities in β-poly­morph structure, the major difference between triglycerides with even or odd chains (indicated by published long spacing and melting point alternation) must be due to the methyl end group pack­ing - i.e., the end group packing volume for the odd-chain glycerides must be larger than found for the even-chain materials.
New Cembranoids from Tobacco, II
Authors: Bylov Anne-Marie , Brümmer Ursula , Hass Werner , Seehofer Friedlieb , Heemann Volker
Published: August 2018

The methylethers 4-O,8-O-dimethyl-(1S, 2E, 4R, 6E, 8S, 11E)-2,6,11-cembratriene-4,8-diol (9), 4-O-methyl-(1S, 2E, 4R, 7E, 11E)-2,7,11-cembratriene-4,6-diol (4) und 4-O,6-O-methyl-(1S, 2E, 4R, 7E, 11E)-2,7,11-cembratriene-4,6-diol (8) were identified as new natural products from tobacco. They were isolated from processed tobacco as well as from leaf surface gum of fresh tobacco.

The spectral data of all six methylethers of (1S, 2E, 4S, 6R, 7E, 11E)- and (1S, 2E, 4R, 6R, 7E, 11E)-2,7,11-cembratrienen-4,6-diol are given.
Relationship between Flower Development, Anthocyanin Accumulation and Activity o f Enzymes Involved in Flavonoid Biosynthesis in Matthiola incana R. Br
Authors: Dangelmayr B. , Stotz G. , Spribille R. , Forkmann G.
Published: August 2018

The activity of five enzymes concerning anthocyanin biosynthesis as well as the anthocyanin accumulation were studied during the development of buds and flowers of Matthiola incana. The investigations included the first three enzymes in the anthocyanin pathway, chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase, and the flavonoid-modifying enzymes, flavonoid 3'-hydroxylase and flavonoid 3-O-glucosyltransferase. The bud and flower development was subdivided into eight stages with respect to morphological criteria. On a fresh weight basis, a substantial correlation between anthocyanin content and the activities of all of the five enzymes were found in the various developmental stages. Furthermore, the anthocyanins formed are obviously not or only less subject to degradation. Although all maxima of activity proved to be in buds, clear differences were observed between the five enzymes with regard to increase and stage of maximum activity. The isolation of other enzymes involved in flavonoid biosynthesis is likely to be most successful in the bud stages.
Biosynthesis of Cyanogenic Glycosides in Butterflies and Moths: Incorporation of Valine and Isoleucine into Linamarin and Lotaustralin by Zygaena and Heliconius Species (Lepidoptera)
Authors: Wray V. , Davis R. H. , Nahrstedt A.
Published: August 2018

C -13 NMR data for linamarin and lotaustralin, obtained after feeding of either Zygaena Jilipendulae or Heliconius melpomone (Lepidoptera) with C-13 enriched valine and isoleucine respectively, indicate that intact units of amino acid with loss of the carboxyl group are incorporated during the biosynthesis of these cyanogenic glycosides.
Hydrogen Bond Indices and Tertiary Structure of Yeast tRNAPhe
Authors: Giambiagi M. S. de , Giambiagi M. , Esquivel D. M. S.
Published: August 2018

The rigidity and stability of the tertiary structure of yeast tRNAPhe is related to a bond index obtained in an IEHT (iterative extended Hückel theory) calculation. The index permits a quantitative estimate of the electron density along the hydrogen bond, having thus an appealing physical meaning. The results indicate that Hoogsteen-type bonds have, as expected, greater electronic population than Watson-Crick type ones. Other non-Watson-Crick pairs, the wobble pair and G15-C48, exhibit high values of the index for the NH ... O bond. In the triples, the electron density of the hydrogen bridges does not weaken (compared with the one of the pairs involved). Contour density maps are shown and dipolar moments of pairs and triples are qualitatively discussed.
Decreased Production of RNA-Streptolysin S in Streptococci Devoid of Extracellular RNase Activity
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

In cultures of certain streptococcal strains, RNA added as a carrier for streptolysin S (SLS) was hardly degraded, owing to deficiency of extracellular RNase activity. Production of RNA-SLS into culture supernatant was markedly reduced in the RNase-deficient streptococci. Even in these RNase-less strains, guanylic-acid rich oligonucleotides, polyG or trypan blue effectively induced SLS production, as in RNase-positive cells. These results demonstrate involvement of the streptococcal nuclease in manifestation of SLS-inducing effect of exogenous RNA. Additional data indicated that cellular growth was promoted by supplementation of RNA, in the nuclease-producing streptococci.
Uptake and Release of Abscisic Acid by Runner Bean Root Tip Segments
Authors: Hartung Wolfram , Dierich Barbara
Published: August 2018

Uptake of abscisic acid by 5 mm long decapped root tips is a linear function of the external ABA concentration in the range of 2.9 × 10-8m to 10-4м and decreases dramatically with in­creasing pH. At pH 8.0 uptake rate is extremely low, even at high ABA concentrations. This indicated that nearly all of the ABA is taken up as the undissociated molecule ABAH. Uptake of ABA is influenced by agents modifying the pH gradients between the medium and the tissue such as salts of weak acids incubated at low external pH (inhibition of uptake and stimulation of ABA release by abolishing the pH gradients), protonophores such as CCCP (inhibition of uptake) and fusicoccin (stimulation of uptake by increasing the pH between medium and cytoplasm). It is concluded that ABA distributes between the compartments of the root cells according to the pH gradients with the undissociated molecule as the only penetrating species. Uptake and release occur without participation of a saturable component by diffusion. In contrast IAA permeates the plasmalemma as both IAAH and IAA-.
Conformational Study of Catecholamines in Solution
Authors: Šolmajer P.
Published: August 2018

Conformations of noradrenaline, dopamine and ephedrine have been studied in aqueous solutions using high resolution PMR spectroscopy. We found that for dopamine the mole fraction of trans rotamer is increased if pH is changed from acidic to basic while for nor­adrenaline and ephedrine the opposite trend is observed: gauche rotamer forms of the side chain become more populated. These changes are discussed in relation to the role of the benzylic hydroxyl group for conformation and/or binding to a receptor site in the biophase.
Notizen: The Effect of Alcohol Oxidase on the Ascorbic Acid-Erythrocyte Interaction: ESR Investigations
Authors: Lohmann W. , Schreiber J. , Holz D.
Published: August 2018

Addition of alcohol oxidase to erythrocytes treated with ascorbic acid reverses the vitamin C effect, as expressed by the appearance of the semidehydroascorbate signal, and the increase in spin concentration. The original erythrocyte electron spin resonance (ESR) signal is, how ever, never restored completely, as it is in the case if ascorbate oxidase is used. Additional interaction between the enzyme alcohol oxidase and haemoglobin iron must occur, since both o f the iron ESR signals at g = 4.3 and g = 6 disappear and the erythrocyte ESR spectrum at g ≈ 2 is changed characteristically. The spin concentration of the latter spectrum increases again above a certain concentration of alcohol oxidase.
Notizen: Receptors for Di-Unsaturated Pheromone Analogues in the Male Summerfruit Tortrix Moth
Authors: Priesner Ernst
Published: August 2018

The antennal Sensilla trichodea in male Adoxophyes orana (F. v. R.) contain specialist receptor cells for 3 reported pheromone components (Z9- and Z11-tetradecenyl acetates and Z9-tetradecen -1-ol) and, additionally, the analogues Z9 ,E11- and Z9,E12-tetradecadienyl acetate. Possible behavioural functions of these dienes are briefly considered.
Notizen: Effect of Ecdysterone on Food Intake of Locusta migratoria Hoppers
Authors: Rao P. J. , Rembold H.
Published: August 2018

Ecdysterone administration at physiological concentra­tions (35 μg /hopper) on alternate days decreased the live weight gain and faecal production in both sexes of 5th instar nymphs of Locusta migratoria. All treated hoppers at this dose failed to moult. No such effects were observed when the hoppers were administered with half of the dose.
Aminoacyl-tRNA Synthetases in Liver, Spleen and Small Intestine of Aged Leukemic and Aged Normal Mice
Authors: Gabius Hans-Joachim , Gabius Sigrun , Graupner Gerhart , Cramer Friedrich , Rehm Sabine
Published: August 2018

The specific activities of 17 aminoacyl-tRNA synthetases in liver, lung, heart, spleen, kidney and small intestine of old female normal and leukemic (reticulum -cell sarcoma, type A) mice have been monitored. No difference appears for lung, heart and kidney; small increases with varying particular changes for liver and marked increases in spleen and small intestine of the tumor bearing mice have been found, following a similar pattern. This finding suggests a coordinated adaptation to modulation of the requirements of protein synthesis imposed by histiocytic sarcoma.
Interaction of Photosystem II Herbicides with Bicarbonate and Formate in Their Effects on Photosynthetic Electron Flow
Authors: Rensen J. J. S. van
Published: August 2018

The reactivation of the Hill reaction in CO2-depleted broken chloroplasts by various concentrations of bicarbonate was measured in the absence and in the presence of photosystem II herbicides. It appears that these herbicides decrease the apparent affinity of the thylakoid membrane for bicarbonate. Different characteristics of bicarbonate binding were observed in chloroplasts of triazine-resistant Amaranthus hybridus compared to the triazine-sensitive biotype. It is concluded that photosystem II herbicides, bicarbonate and formate interact with each other in their binding to the Qв-protein and their interference with photosynthetic electron transport.
Formate as an Inhibitor of Photosynthetic Electron Flow
Authors: Snel Jan F. H. , Naber Dirk , Rensen Jack J. S. van
Published: August 2018

The effects of formate on the Hill reaction in isolated broken pea chloroplasts were in­vestigated. Addition of formate to chloroplasts has two distinct effects: I. basal electron flow can be stimulated 3-fold; 2. uncoupled electron flow is inhibited. The stimulating effect is due to uncoupling by formate and appears instantaneous. Maximal inhibition by form ate is only observed after prolonged illumination. The inhibitory action of form ate on electron flow can be relieved by bicarbonate *.
The Molecular Basis of Triazine-Herbicide Resistance in Higher-Plant Chloroplasts
Authors: Hirschberg Joseph , Bleecker Anthony , Kyle David J. , McIntosh Lee , Arntzen Charles J.
Published: August 2018

Triazine herbicides inhibit photosynthesis by blocking electron transport in photosystem II. The target site of the herbicide was identified as a chloroplast thylakoid polypeptide (the Qв protein) of 32,000 daltons. Studies of triazine-resistant weed biotypes suggested that a subtle change in the Qв protein caused the resistance. We have cloned the chloroplast gene (psbA) that codes this protein from herbicide-resistant and herbicide-susceptible biotypes of Solanum nigrum. By DNA sequencing we detected a single base substitution in the psbA gene of the resistant plants, resulting in an amino acid change (serine to glycine for the susceptible to resistance conversion). This mutation is exactly the same one which we have described in a herbicide-resistant biotype of Amaranthus hybridus.
Herbicide-Binding Protein, Binding Sites and Electron-Transport Activity: Quantitative Relations
Authors: Herrmann Gerhard , Thiel Andreas , Böger Peter
Published: August 2018

In Bumilleriopsis filiformis, the thylakoid-membrane protein showing the highest turnover in the light has an apparent molecular weight of 35 kDa. Loss of this protein after chlor-amphenicol treatment leads to a corresponding reduction of herbicide-binding sites as well as photosystem-II activity (measured by e.g. H2O → silicomolybdate) and cellular photosynthesis. This correlation is quantitated by comparison of the amount of herbicide-binding protein (autoradiography), electron transport, and herbicide binding. An increase of the binding constant after chloramphenicol treatment is evident.
Herbicides which Interfere with the Biosynthesis of Carotenoids and Their Effect on Pigment Excitation, Chlorophyll Fluorescence and Pigment Composition of the Thylakoid Membrane
Authors: Grumbach K. H.
Published: August 2018

Plants grown in the presence of the herbicides assayed synthesized chlorophylls during growth at low fluence rates. Subsequent irradiation with higher fluence rates of red light induced a strong chlorosis with SAN 6706 being a much stronger herbicide than J 852 or amino-triazole. All herbicides assayed also changed the content and composition of chlorophylls, carotenoids and pigment-protein-complexes of the thylakoid membrane and therefore the pigment excitation and chlorophyll fluorescence emission spectra of the plastid. With increasing herbicide toxicity the main characteristic emission bands at 690 and 730 nm disappeared and new emission bands at 715 (J 852) and 700 nm (SAN 6706) appeared. Such “artificial” membranes with a changed pigment composition were very susceptible to light. Presented data may be taken as evidence, that the lack of photoprotective cyclic carotenoids caused by the specific action of a bleaching herbicide is the primary event that may lead to a disturbed formation of the thylakoid membrane and its destruction by light and oxygen.
Interaction of Herbicides with Pea Chloroplasts
Authors: Singh K. N. , Prakash J. , Agarwal A. K. , Singhal G. S.
Published: August 2018

We have studied the effect of three herbicides viz., triazole, pyrazon and metribuzin on total chlorophyll, carotenoids and cell protein in leaves, and PS II and PS I activity in the chloroplasts isolated from control and herbicide treated pea plants. Pyrazon and metribuzin at 10μм concentration affect these parameters resulting in the chlorosis of the leaves.
07g and D6a: Two Flavone Glycosylating Genes in Silene, which are Only Expressed in Cotyledons and Rosette Leaves
Authors: Steyns J. M. , Mastenbroek O. , Nigtevecht G. van , Brederode J. van
Published: August 2018

Two further loci can be added to the three already known (g, gl and fg) in Silene controlling the 7-O and 2″-O-glycosylation of the C-glycosylflavone isovitexin (6-C-glucosylapigenin). These loci, O7g for the 7-O-galactosylation and D6a for the 2″-O-arabinosylation, appear only to be expressed in cotyledons and rosette leaves and control the biosynthesis of isovitexin 7-O- galactoside and isovitexin 7-O-galactose 2″-O-arabinoside in these parts of plants in which the recessive alleles of the loci g, gl and fg are homozygous (Steyns et al. [9]).

The possibility that locus g, whose dominant alleles gG and gX control the 7-O-glucosylation and the 7-O-xylosylation of isovitexin respectively, controls the synthesis of isovitexin-7-O- galactoside was excluded by demonstrating the presence of isovitexin-7-O-galactoside and the 7-O-galactosyltransferase catalyzing its biosynthesis in addition to isovitexin-7-O-glucoside and the 7-O-glucosyltransferase in cotyledons of gGgG seedlings.

The synthesis of the 2″-O-arabinoside is neither controlled by locus gl, whose dominant alleles glR and glA control the 2″-O-rhamnosylation and 2″-O-arabinosylation of isovitexin respectively, nor by locus fg, whose dominant allele Fg controls the biosynthesis of isovitexin 2″-O-glucoside. This was shown by the presence of isovitexin-7-O-galactose 2″-O-arabinoside and the 2″-O-arabinosyltransferase catalyzing the synthesis of the 2″-O-arabinoside in addition to isovitexin-7-O-galactose 2″-O-rhamnoside in cotyledons of glRglR seedlings and by the presence of isovitexin-7-O-galactose 2″-O-arabinoside and the 2″-O-arabinosyltransferase in addition to isovitexin-7-O-galactose 2″-O-glucoside and the 2″-O-glucosyltransferase in cotyledons of Fg Fg seedlings.
Inhibition of Photosynthetic Reactions by Aureomycin
Authors: Ye Ji-yu , Heber U.
Published: August 2018

The effect of aureomycin on photosynthesis was investigated. This antibiotic which has been reported to stimulate photosynthesis at very low concentrations is an effective inhibitor at higher concentrations. In mesophyll protoplasts and isolated chloroplasts from spinach, 50% inhibition of CO2 reduction required about 20 μᴍ aureomycin. The reduction of 3-phosphoglycerate and of oxaloacetate by intact chloroplasts was also inhibited, but not that of nitrite and methylviologen which was actually stimulated. NADP reduction by broken chloroplasts and methylviologen- dependent photophosphorylation were also sensitive to aureomycin. The electrochromic shift at 518 nm which indicates formation of a light-dependent membrane potential was suppressed in the presence of 200 μᴍ aureomycin and the transthylakoid proton gradient was decreased. The data confirm reports that aureomycin has uncoupling properties, and they indicate that it also acts as an inhibitor of ferredoxin/NADP reductase.
HPLC Analysis of Alkaloids in Extracts of Callus Cultures of Cinchona Species
Authors: Verpoorte Robert , Mulder-Krieger Thea , Wijnsma Rommert , Verzijl Jacques M. , Svendsen Anders Baerheim
Published: August 2018

The quantitative analysis of the alkaloids in Cinchona tissue cultures by means of a reversed-phase ion pair HPLC method is reported.
Lysine-Enhanced Threonine-Inhibition of Bacterial Aspartokinase: Concerted or Synergistic Feedback Inhibition?
Authors: Klemme Jobst-Heinrich
Published: August 2018

The concept of concerted and synergistic feedback inhibition of the regulatory enzyme of a branched bio­synthetic pathway is critically discussed on the basis of data obtained with the threonine-lysine-sensitive asparto- kinase of Rhodospirillum rubrum. It is proposed that only one name (concerted feedback) should be used to specify allosteric feedback inhibitions where at least two end- products of the branched pathway are required for complete inhibition of the regulatory enzyme.
Neuartige Ceramide aus Cystobacter fuscus (Myxobacterales) / Novel Ceramides from Cystobacter fuscus(Myxobacterales)
Authors: Eckau H. , Dill D. , Budzikiewicz H.
Published: August 2018

From cell material of Cystobacter fuscus strain Cb 685 (Myxobacterales) the ceramides 2S ,3R-N-(2′R-hydroxy-15′-methylpalmitoyl)-17-methylsphinga-4E,8E-dienine (1), 2S.3R-N-(2′R-hydroxypalmitoyl)-17-methylsphinga-4E,8E-dienine (10), 2S ,3R-N-(2′R-hydroxy-15′-methyl)-17-methyl-4E-sphingenine (11) and 2S,.3R-N-(2′R-hydroxy-15′-methylpalmitoyl)-17-methylsphinganine ( 12) could be isolated, the structure elu cidation of which is being reported here. The carotenoid myxobactone could be identified as the main pigment.
The Influence of Amino Acid Ligands and Vitamin C on the Reduction Potential of Fe(III): Polarographie and Electron Spin Resonance Investigations
Authors: Kiefer Berthold , Sapper Helmut , Lohmann Wolfgang
Published: August 2018

The pH dependence of Fe(III)-amino acid complexes has been studied polarographically and by means of ESR spectroscopy.

It could be shown that, at least, two complexes exist: one with a low molecular weight, ESR detectable at acid pH. and one with a high molecular w eight at alkaline pH, ESR non detectable. The half wave potential of Fe (III) is lowered by amino acid ligands.

The redox interaction of the Fe(III)-amino acid complexes with vitamin C results in a decrease of the ascorbyl radical concentration. Ascorbic acid also forms a complex with Fe(III) as in­dicated by a polarographic half wave potential near -0.55 V vs. S.C.E. at pH 7.
Legume Root Response to Symbiotic Infection. Enzymes of the Peribacteroid Space
Authors: Mellor Robert B. , Mörschel Erhard , Werner Dietrich
Published: August 2018

Three of the major soluble partitioned pools in the symbiotic cell, namely the host cell cytoplasm, the cytoplasm of the bacterial symbiont and the space between the two partners (the peribacteroid space) were assayed for selected enzymes. Whilst alanine dehydrogenase was found almost totally in the bacterial cell cytoplasm, other enzymes were more widely spread. Amongst these a-mannosidase, previously described as a vacuolar marker enzyme in eukaryotes, was found largely in the peribacteroid space.

These results are discussed in relation to models of peribacteroid membrane biogenesis.
Conductivity of Normal and Pathological Human Erythrocytes (Homozygous β-Thalassemia) at Radiowave Frequencies
Authors: Ballario C. , Bonincontro A. , Cametti C. , Rosi A. , Sportelli L.
Published: August 2018

The conductivity of normal and homozygous β-thalassemic erythrocyte suspensions has been measured over the frequency range from 5 KHz to 100 MHz in the temperature interval from 5 to 45 °C.

The electrical parameters of the membrane, i.e., the capacitance CM and the conductance GM per unit surface have been calculated from an expression given by Hanai for the conductivity of a suspension of ellipsoidal particles covered with a shell.

Some interesting differences between the normal and pathological state are evidentiated.
ESR Investigations on Lyophilized Blood: Mixtures with Ascorbic Acid
Authors: Neubacher Harald
Published: August 2018

The main contribution to ESR spectra of lyophilized tissues of plant or animal origin usually is given by an anisotropic singlet, which is known to be caused at least in the majority of cases by the adsorption of an ascorbyl radical. Model systems have been in vestigated in order to discuss experimental parameters, which in fluence these spectra qualitatively and quantitatively.
Preparation of an Affinity Chromatographic System for the Separation of ADP Binding Proteins
Authors: Bieber Elke , Woenckhaus Christoph , Pauli Harald
Published: August 2018

[4-(3-Bromoacetylpyridinio)-butyl]adenosine pyrophosphate as a structural analog of NAD+ reacts covalently with the sulfhydryl groups of thiopropyl agarose. 10-20 μmol can be bound to 1 ml gel. Stabilization of the insoluble coenzym e is attained by treatment with sodium boro hydride (NaBH4). This complex when applied to column chromatography, allow s the separation of various dehydrogenases as a result of their different complex stability coefficients. Alcohol dehydrogenase from liver, lactate dehydrogenase, and adenylate kinase, which all bind to the ADP-analog residues of the gel matrix, can thus be separated by different salt gradients. Alcohol dehydrogenase from yeast, however, does not form a complex and can easily be eluted from the column with phosphate buffer. Glyceraldehyde-3 phosphate and aldehyde dehydrogenases can be eluted by the addition of NAD+ or NADH to the buffer. The uncharged 1,4-dihydropyridin ring of the reduced coenzyme produces a more stable complex with the dehydrogenases than the oxidized form.
A Simple Method to Prepare Affinity Resins on Cellulose Basis
Authors: Eisele Karl , Costa Fernando Dias , Pascual Carlos , Ofenloch-Hähnle Beatus
Published: August 2018

Affinity resins with different spacer arms were synthesized analogues to the solid phase peptide synthesis using aminoethyl cellulose or carboxymethyl cellulose as matrix. The spacer arms could be varied in length and rigidity. Especially spacer arms consisting of poly am ino acids can be synthesized with a defined amount of amino acid residues specifically in the low molecular weight ranges. The method is also applicable to other matrices w hich are not susceptible to 1 ɴ HCl in glacial acetic acid, trethylamine, methylene chloride and dimethylformamide.

The synthesis of affinity resins with different spacer arms for the purification of androgen receptors is described as an example of the method.
Isolation of the Adducts of Platinum Complexes and Nucleic Acid Bases on the Dowex 50 W Column
Authors: Olinski Ryszard , Walter Zofia
Published: August 2018

The method presented here enables the isolation of three monofunctional adducts. These are: platination of cytosine, adenine and guanosine. The three detected bifunctional complexes were: guanine N7 to N7, adenine N7 to N7 and adenine N7 to N1. A mixed bifunctional complex of guanine and adenosine and the product of polymerization of three adenines and two moieties of cis DDP were also detected.

In the peak eluted separately from the guanine standard, no Pt was detected. The sample eluted in this peak had UV spectrum different from the standard and may represent the degraded product of guanine and polymerized Pt.
Structural Studies on the Galactan from the Albumin Gland of Achatina fulica
Authors: Holst Otto , Mayer Hubert , Okotore Rufus O. , König Wilfried A.
Published: August 2018

The structure of the galactan isolated from the album in gland of Achatina fulica (African giant snail) was investigated by methylation analyses. The molecule is highly branched. The linkages of the exclusively present D-galactose are 1→3 and /or 1→6. From lectin binding studies it was learnt that the 1→3 linkages possess β-configuration. The anomeric configuration of the 1→6 linkage is unknown. A tentative structure of the galactan is proposed.
High Energy Radiation-Induced Crosslinking of Histone Octamer Complexes
Authors: Deeg K.-J. , Katsikas L. , Schnabel W.
Published: August 2018

Calf thymus histone octamer complexes were irradiated in the native state in N2O-saturated dilute aqueous solution (0.5 g/l, pH 9, [NaClO4] = 1-4 mol/1) with 50 or 100 ns pulses of 16 MeV electrons or 60Co-γ-rays. Tim e resolved light scattering measurem ents and optical ab­sorption measurements yielded the following: the octamers underwent a volume contraction due to intra-complex-crosslinking induced by the attack of OH-radicals. Crosslinking proceeded to a certain extent via 2 ,2′-biphenol coupling as inferred from product analyses.
Effects of Membrane-Acting Drugs and Aerobiosis on Production of Streptolysin S and Nuclease in Hemolytic Streptococci
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

Yield of streptolysin S (SLS) in streptococcal culture was considerably reduced by procaine, dibucaine, atropine or chlorpromazine at concentrations which scarecely affected production of an extracellular nuclease as well as the bacterial growth. Cerulenin was also inhibitory to SLS formation, but its effect was more pronounced on the nuclease production. By aerobiosis, amount of SLS produced into culture supernatant was increased significantly, whereas yield of the nuclease was rather unaffected.
Impaired Diffusion Coupling-Source of Arrhythmia in Cell Systems
Authors: Schreiber Igor , Kubíček Milan , Marek Miloš
Published: August 2018

A detailed analytical and numerical analysis of a simple reaction-diffusion model of the source of non-homogeneities and arrhythmias in an originally homogeneous reaction system is presented. Solution, bifurcation and evolution diagrams are used to describe the behaviour of the model. It is shown that under certain conditions steady and/or oscillatory nonhomogeneous states are the only stable solutions of the model. These phenomena are essentially not dependent on a particular reaction kinetics. A possible relevance to some biological situations is discussed.
Stimulierung der Immunreaktivität gegen endogene Retroviren und Schutz gegen Leukämie bei älteren AKR-Mäusen nach Impfung mit Antikörpern gegen Virusoberflächen-Komponenten. Rolle des Antikörpers gegen p15(E) / Stimulation of Immunoreactivity against Endogenous Retroviruses and Protection against Leukem ia of Older AKR Mice by Treatment with Antibodies against Retroviral Surface Components. Role of p15 (E) Antibody
Authors: Schwarz Heinz , Thiel H.-J. , Weinhold Kent J. , Bolognesi Dani P. , Schäfer Werner
Published: August 2018

Antibody against viral gp71 is effective therapeutically for high leukemic AKR mice if injected immediately after birth [1], No corresponding effect could be observed after inoculation later in life when the endogenous virus burden is already high. However, if antibody treatment was supplemented by the injection of pi5(E) antibody, a thera­peutic effect was observed even in older mice first treated at an age of 21/2 months. Those mice produced antibodies against viral surface proteins and appeared to be able to survive longer than control mice. Thus pi5(E) antibody might be able to overcome retroviral associated immuno­deficiency. This therapy may have implications for the treatment of the apparently retroviral induced aquired immunodeficiency syndrome (AIDS) of man.
Aurintricarboxylic Acid and Polynucleotides as Novel Inhibitors of Ribonucleotide Reductases
Authors: Baumann Helga , Hofmann Rüdiger , Lammers Manfred , Schimpff-Weiland Gabrile , Follmann Hartmut
Published: August 2018

Ribonucleoside diphosphate reductases isolated from Escherichia coli, baker’s yeast, Ehrlich ascites tumor cells, and a unicellular green alga (Scenedesmus obliquus) are inhibited strongly and uniformly by the polymeric triphenylmethane dye, aurintricarboxylic acid. The molecule appears to interact simultaneously with the enzyme’s various nucleotide and catalytic (iron-organic radical) sites. Oligo- and polyribonucleotides are also inhibitory. These reactions serve as models of the probably physiologic regulation of ribonucleotide reduction exerted by natural inhibitors. Partial characterization of an inhibitor fraction found in wheat seed embryo is described
Activation Volumes of the Calcium Dependent para-Nitrophenyl Phosphate Hydrolysis of the Sarcoplasmic Reticulum Calcium Transport Enzyme
Authors: König Klaus Georg , Hasselbach Wilhelm
Published: August 2018

The effect of pressure on the calcium dependent hydrolysis of para-nitrophenyl phosphate by the calcium transport enzyme of the sarcoplasmic reticulum was studied under different conditions: temperature, solutes, substrate and ion concentrations. The calcium transport enzyme exhibits a large positive activation volume which does neither depend on the enzyme’s inhibition by high salt concentrations nor its activation by ethylene glycol. The activation volume further proves to be pressure-independent but exhibits a pronounced negative temperature coefficient. The volume changes connected with the entrance of para-nitrophenyl phosphate, calcium or magnesium ions into the substrate ion complex are quite small, indicating that the transfer of water connected with the binding of these ligands is compensated by volume changes of the protein, accompanying the transition of the enzyme from its activated into its ground state
Alteration of Acylphosphate Formation of Cardiac Sarcoplasmic Reticulum ATPase by Calmodulin-Dependent Phosphorylation
Authors: Pifl Christian , Plank Brigitte , Hellmann Gertrude , Wyskovsky Wolfgang , Suko Josef
Published: August 2018

The calcium-dependent acylphosphate formed by the calcium transport ATPase of cardiac sarcoplasmic reticulum and the calcium-, calm odulin-dependent phosphoester(s) of sarcoplasmic reticulum fractions formed by a calcium-, calmodulin-dependent membrane-bound protein kinase can be distinguished by removal of calcium and/or magnesium by EDTA or hydroxylamine treatment of the acid denaturated membranes. Both procedures decompose the acylphosphate with little effect on the phosphoester(s).

Calmodulin-dependent phosphorylation (2.44 nmol/mg SR protein) reduces the apparent K(Ca) of the acylphosphate steady state level of the calcium transport ATPase from 0.56 to 0.34 μM free calcium, without affecting the maximum phosphoenzyme level (0.93 versus 0.89 nmol/mg protein), and has little, if any, effect on the Hill-coefficient (1.32 versus 1.54)