bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Role of the Qв Binding Protein in the Mechanism of Cyanobacterial Adaptation to Light Intensity?
Authors: Koenig Friederike 
Published: August 2018

Growth of the unicellular blue-green alga Anacystis nidulans in media containing sublethal concentrations of DCMU-type inhibitors of photosynthetic electron transport in strong white light gave rise to shade type appearance in this organism, as characterized by an increased ratio of phycocyanin to chlorophyll and reduced ratios, both, of carotenoids to chlorophyll and of total chlorophyll to P700. Shade type in Anacystis was caused neither by phenolic inhibitors tested nor by those known to bind to the cytochrome b6/f-complex. Surprisingly enough, the molar ratio of phycocyanin to chlorophyll in artificially shade adapted Anacystis1 grown in strong white light in the presence of 10-6 м atrazine, was found to increase with temperature for a given light intensity and with light intensity for a given temperature.
Mutants of Anaeystis with a reduced binding capacity for DCMU-type herbicides due to an amino acid exchange in the 32 kDa Qв-binding polypeptide, also called D-1 protein, were ob- served to show shade type appearance in strong light, to respond very little to changes in light intensity and to show a reduced capability to further change their appearance to shade type by binding of competitors of Ob to the 32 kDa polypeptide.
In Anaeystis a concentration of atrazine (10-7 м), ten times lower than the one causing the highest rate of shade adaptation (10-6 м), was shown to induce an optimum in cell density, which in turn resulted in an optimum in light-dependent O2 evolution. Both factors together might be responsible for the so-called greening effect observed in higher plants treated with sublethal concentrations of DCMU-type inhibitors of photosynthetic electron transport.
n-Alkylphenole aus Schinus terebinthifolius RADDI (Anacardiaceae) / n-Alkylphenols from Schinus terebinthifolius RADDI (Anacardiaceae)
Authors: Skopp G. , Opferkuch H.-J. , Schwenker G . 
Published: August 2018

Abstract
The isolation of n-alkylphenols from the drupes of Schinus terebinthifolius is described for the first time. The 1H -NMR parameters, especially those for the triolefinic and monoolefinic components, are presented. Structures were proved by calculated spectra. Skin irritating activities were determined
Reactions of Substituted Arenediazonium Chlorides with Methylamine- Formaldehyde Premix Revisited: Reactivity and Transformations of Methylolamine Intermediates and Their Biological Significance
Authors: Kolar George F. , Schendzielorz Michael 
Published: August 2018

Abstract
Modulation of the N-azo coupling betw een ring-substituted arenediazonium chlorides and premixed m ethylam ine-form aldehyde leads not only to 1-aryl-3-hydroxymethyl-3-methyltriazenes and their dimers, but also to unexpected cyclic and com plex products. The syntheses comprise reactions with arenediazonium chlorides bearing both - M and + M substituents at para and ortho/para positions of the phenyl ring. One of the major constituents isolated from a mixture of products is the O-acetate ot 3-hydroxymethyl-3-methyl-1-(2,4,6>-trichlorophenyl)triazene. This product was obtained from the reaction of 2,4,6-trichlorobenzenediazonium chloride and methylamine- formaldehyde mixture which was then stabilized by acetylation.
The structures of the isolated products could be derived from reactive methylolamines and electrophilic intermediates that possibly occur in vivo and thereby offer a plausible mechanistic explanation for the carcinogenic and tumour-inhibitory activity associated with the open-chain triazene com pounds in the living cell.
Protein Transport in Chloroplasts: ATP is Prerequisit
Authors: Schindler Christine , Hracky Ruth , Soll Jürgen 
Published: August 2018

Abstract
The energy requirement for protein transport into chloroplast was assayed under conditions that perm it to distinguish whether the posttranslational translocation is dependent on ATP or whether a membrane potential across the chloroplast envelope can drive this transport event.
A membrane potential is not required for translocation. ATP can support protein transport in the presence of protonophores and ionophores. Non-hydrolyzable ATP analogues and GTP, CTP, UTP cannot serve as ATP substitutes. Translocation could be observed when an ATP generating system was used to supply ATP. In contrast ATP degrading systems completely abolished translocation.
The inner envelope mem brane localized ATP-ase is probably not involved in the transport event. The results suggest that ATP is needed at the outer chloroplast envelope.
Inhibition of protein transport by ADP, pyrophosphate and NaF is studied and its consequences discussed.
The Separation of Two Different Enzymes Catalyzing the Formation of Hydroxycinnamic A dd Glucosides and Esters
Authors: Bäumker Paul Alfred , Jütte Michael , Wiermann Rolf 
Published: August 2018

Protein extracts from anthers of Tulipa cv. Apcldoorn catalyze the formation of glucosidcs and glucose esters of hydroxycinnamic acid with UDP-glucose as the glucosyl donor. By chromatofocusing and by HPLC (anion exchange chromatography) it could be demonstrated for the first time that two different enzymes are involved in these reactions. By using the molecular sieving (HPLC) a molecular weight of about 45000 D was determined for the GT (E) (= catalyz­ing the formation of esters) and of about 25000 D for the GT (G) (= catalyzing the formation of glucosidcs). Both enzymes exhibit a high spezificity for free hydroxycinnamic acids.
It is assumed that these transferases arc involved in the formation of feruloylglucose and ferulic acid glucoside, the latter of which can be isolated from anthers at early developmental stages. Furthermore, it is hypothesized that feruloylglucose functions as a starter molecule for the transacylation reaction by which di- and triferulovlsucrose are formed.
Major Flavanones from Lonchocarpus guatamalensis
Authors: Ingham John L. , Tahara Satoshi , Dziedzic Stanley 
Published: August 2018

Abstract
The flavanones 2 S-lupinifolin and 2R:3R-lupinifolinol have been isolated as major components from a methanolic extract of Lonchocarpus guatamalensis root bark. These known compounds occur together with a minor flavanone (2R:3R-3-O-methyl-lupinifolinol) not previously recognized as a natural product.
Glutaric Acid as a Catabolite of Nicotinic Acid in Parsley Cell Suspension Cultures
Authors: Komoßa Dieter , Barz Wolfgang 
Published: August 2018

Abstract
A degradation product of nicotinic acid representing the pyridine carbon skeleton was isolated and purified from parsley cell suspension cultures after incubation with [6-14C]nicotinic acid for 70 h. The catabolite was identified as glutaric acid by means of spectroscopic (GC-MS and 1H NMR) and chromatographic (TLC, HPLC) techniques. Glutaric acid when applied to parsley cell cultures was readily degraded to CO2 but intermediate products could not be identified.
Acetolactate Synthase from Barley (Hordeum vulgare L.): Purification and Partial Characterization
Authors: Durner Jörg , Böger Peter 
Published: August 2018

Abstract
Acetolactate synthase (EC 4.1.3.18; ALS) has been extracted from etiolated barley shoots (Hordeum vulgare L.) and purified to near homogeneity. Purification was made possible by a fivestep procedure using hydrophobic interaction, gel filtration, anion-exchange and hydroxylapatite chromatography, the last two steps performed with an HPLC- and FPLC-system, respectively. A 300-fold purification was achieved representing 13% of the initial activity in the crude extract; only small amounts of pure acetolactate synthase could be isolated. Although the enzyme was found labile during the chromatographic steps, purified ALS maintained its activity for several hours and could be stored at 70 K for weeks with a 15-30% loss.
The apparent molecular weights of the enzymatically active species as determined by gel filtration were about 440 kDa and 200 kDa, respectively. We assume these species are no isozymes but different polymeric forms of a basic unit of ALS. SDS-PAGE analysis showed one polypeptide with an apparent molecular weight of 58 kDa. Preliminary enzymatic characterization of the purified enzyme confirms a marked synergism in the feedback control by branched-chain amino acids. The combination of valine plus leucine exhibited the most co-operative inhibition.
Assessment of Persisting Chromosome Aberrations by Flow Karyotyping of Cloned Chinese Hamster Cells
Authors: Otto Friedrich J. 
Published: August 2018

Abstract
A preparation, staining and measuring protocol for high resolution flow cytometry of chromosomes was developed. This method allows us to identify all chromosome types and is suited for characterization of permanent cell lines and cell clones by establishing their flow karyotypes. In cell clones this procedure can be used for the detection of chromosomal aberrations which appear spontaneously or are induced by mutagen treatment and persist in the cell population.
The Effects of the Herbicide Sethoxydim on Transport Processes in Sensitive and Tolerant Grass Species II. Effects on Membrane-Bound Redox Systems in Plant Cells
Authors: Weber Angela , Lüttge Ulrich 
Published: August 2018

Leaf slices of sethoxydim-sensitive (Poa pratensis, Festuca ovina) and tolerant (Poa annua, Festuca rubra) grass species were found to be able to reduce extracellular ferricyanide by electron transport across the plasmalemma. This reduction was inhibited by the herbicide sethoxydim, and the sensitive species were much more strongly affected than the tolerant ones. The inhibition was concentration dependent. Sethoxydim affected the electron transport in isolated Poo chloroplasts. Polarographic and photometric measurements of ferricyanide reduction suggested photosystem II to be the site of action. Inhibition occurred only in the sensitive species Poa pratensis and was linearly dependent on concentration. In isolated mitochondria from sensitive Zea mays coleoptiles sethoxydim also acted as an inhibitor of electron transport. Only slight inhibition was measured with mitochondria from tubers of tolerant potato (Solanum tuberosum).
It is concluded that sethoxydim generally acts as inhibitor of membrane-bound redox systems. The specific inhibition of the plasmalemma-bound redox system of sethoxydim-sensitive plants could contribute to a selective action of the herbicide.
Lipid Composition of Photosystem I and II in the Tobacco Mutant Nicotiana tabacum NC 95
Authors: Bednarz J. , Radunz A. , Schmid G. H. 
Published: August 2018

The lipids of photosystem II particles, of chloroplasts and leaves are compared in the variegated tobacco mutant NC 95. The mutant differs from other N. tabacum mutants by the phenomenon that it has variegated leaves with green and with yellow-green leaf patches. Chloroplasts from the green leaf areas exhibit photosystem II and photosystem I reactions and have a normal lamellar system with grana and intergrana regions. Chloroplasts from the yellow-green leaf areas, however, yield only photosystem I reactions and have only single stranded isolated thylakoids. Hence, this mutant offers the unique possibility to compare without the use of detergents within the same plant the lipid composition of photosystem II particles with that in intact chloroplasts, exhibiting either photosystem II and I reactions or those exhibiting exclusively photosystem I reactions.
The lipids of photosystem II particles are composed of 37 % glycolipids, 4 % phospholipids, 5 % carotenoids and 54 % chlorophyll. Lipids of chloroplasts with grana stacking are composed of 75% glycolipids, 7 % phospholipids, 2 % carotenoids and 16% chlorophyll. Chloroplasts with single isolated thylakoids have a lipid composition consisting of 8 3 % glycolipids, 14% phospholipids and only 0.5% carotenoids and 2 % chlorophyll. The chloroplast lipid mixture is characterized in comparison to the respective leaf lipid mixture by a 16-17% higher glycolipid portion and by a 13-70% lower phospholipid content.
The main difference in the lipid composition of photosystem I and II consists in the observation that chloroplasts active in only photosystem I contain more than double the amount of glycolipids and the 4-fold amount of phospholipids in comparison to photosystem II active preparations. The amount of monogalactolipid is even 3 times higher in chloroplasts active only in photosystem I when compared to those in photosystem II particles. In photosystem II particles phosphatidylethanolamine is completely lacking and phosphatidylglycerol and phosphatidylinositol occur only in traces.
The fatty acids of the sulfolipid are by 45 % more saturated in the photosystem II particles and the digalactolipids of the photosystem II particles are by 28 % more saturated than in chloroplasts exhibiting photosystem I and II activity.
Metabolism of Ferulic Acid Sucrose Esters in Anthers of Tulipa cv. Apeldoorn: II. Highly Specific Degradation of the Esters by Different Esterase Activities
Authors: Bäumker P. A. , Arendt S. , Wiermann R. 
Published: August 2018

Abstract
Protein extracts from anthers of Tulipa cv. Apeldoorn catalyze the degradation of ferulic acid sucrose esters. Different products are generated when triferuloyl sucrose (TFS) and diferuloyl sucrose (DFS) were applied as substrates. By the aid of reversed-phase HPLC , TLC and spectroscopy the products could be identified as free ferulic acid, monoferuloyl sucrose ester [feruloylsucrose(mono)] and two different diesters of ferulic acid and sucrose [feruloylsucrose(di) and the endogenously occurring diferuloylsucrose (DFS)]. By means of protein fractionation (chromatofocusing, anion exchange HPLC and molecular sieving HPLC) , four different enzyme activities involved in the degradation process could be separated. According to their catalytic properties, they were characterized as esterases (= EA).
The partially purified esterase activity I (EAI) obtained after fractionation by chromatofocusing catalyzes the formation of feruloylsucrose(di) and ferulic acid when TFS is used as substrate. Incubations with EA la or EA Ib isolated in smaller portions lead to the same product pattern.
The esterase activity II (EA II) degrades TFS to ferulic acid and DFS . DFS as substrate is only accepted by the EA I activities, in all three cases ferulic acid and feruloyl sucrose(mono) are formed as products. The kinds of different degradation reactions clearly indicate that one enzyme (= the EA II activity) catalyzes exclusively the formation of DFS from TFS.
Both enzymes, EA I and EA II, exhibit a high specificity towards ferulic acid sucrose esters. Hydroxycinnamic sucrose esters with only sinapic acid moieties do not function as substrates. When enzymatically formed sucrose esters like feruloylsucrose(di), feruloylsucrose(mono) and monosinapoylsucrose were used as substrates, no product formation could be observed. Applying SFS as substrate, only the ferulic acid moiety was released by EA I. Further, naturally occurring esters (glucose- and CoA-esters of p-coumaric, caffeic, ferulic and sinapic acid; chlorogenic acid; BGM ) tested so far were not degraded by EA I and EA II. It is assumed that these esterase activities play a specific role in the ferulic acid metabolism in Tulipa anthers.
Accumulation of Protoporphyrin IX in the Presence of Peroxidizing Herbicides
Authors: Sandmann Gerhard , Böger Peter 
Published: August 2018

Abstract
Peroxidizing herbicides were assayed for their capacity to accumulate tetrapyrrole-like compounds in the liquid culture medium when growing the xanthophycean alga Bumilleriopsis filiformis. We have isolated and purified this compound by HPLC . For identification optical, fluorescence, NMR and mass spectroscopy were employed. All these techniques showed that the accumulation product is protoporphyrin IX. This tetrapyrrole was found, although to a different extent, using either chlorophthalim, oxadiazon, oxyfluorfen or LS 82-556. Accumulation of protoporphyrin IX caused by peroxidizing compounds was also found in light-grown Bumilleriopsis cells and heterotrophically (dark-)grown Scenedesmus cells, but neither in light-grown Scenedesmus cells nor in dark-grown Neurospora.
Characterization of Two Soluble Basic Cytochromes Isolated from the Anoxygenic Phototrophic Sulfur Bacterium Chlorobium phaeobacteroides
Authors: Fischer Ulrich 
Published: August 2018

Abstract
Chlorobium phaeobacteroides contains two soluble basic c-type cytochromes, a flavocytochrome c-552 and a small cytochrome c-555. Both electron transfer proteins were highly purified by ion exchange chromatography and gel filtration.
The flavocytochrome c-552 exhibits maxima at 552 nm, 523 nm and 416 nm in the reduced state and at 409.5 nm with two shoulders at 440 nm and 480 nm in the oxidized form. The best purity index (A280/A416)obtained was 0.65. The molecular properties of this flavocytochrome are as follows: isoelectric point, pH 9.5 - 10; redox potential, +63 mV; molecular weight, 56,000.
Cytochrome c-555 is a small basic hemoprotein with an isoelectric point of pH 9.5 - 10, a molecular weight of 9,500 and a midpoint redox potential of +105 mV. The best purity index {A280/A418) obtained was 0.176. The oxidized form of this cytochrome has a maximum at 411.5 nm, while the reduced state shows three maxima (α-band at 554.5 nm; β-band at 523 nm, and γ-band at 418 nm). The a-band is asymmetrical with a typical shoulder at 551 nm.
Different Porphobilinogenases in Cytoplasm and Isolated Chloroplasts from Light-Grown Euglena gracilis Z.
Authors: Juknat A. A. , Dörnemann D. , Senger H. 
Published: August 2018

Abstract
Lysed cells as well as different fractions of isolated, disrupted chloroplasts from light grown Euglena gracilis were tested for their capability of porphyrin biosynthesis. It is shown that the formation of the soluble porphobilinogenase (PBG-ase) fraction is inhibited by cycloheximide indicating its biosyntheses on 80S ribosomes, whereas the formation of the membrane bound chloroplast PBG-ase is chloramphenicol sensitive. Different pH-optima are demonstrated for the two enzymes. From the presented results it is deduced from those isolated from dark grown cells.
Acclimation of the Photosynthetic Apparatus to Photosystem I or Photosystem II Light: Evidence from Quantum Yield Measurements and Fluorescence Spectroscopy of Cyanobacterial Cells
Authors: Melis Anastasios , Mullineaux Conrad W. , Allen John F. 
Published: August 2018

Abstract
Cells of the cyanobacterium Synechococcus 6301 were grown under illumination whose spectral composition favoured absorption either by the phycobilisome (PBS) light-harvesting antenna of photosystem II (PS II) or by the chlorophyll (Chi) a light-harvesting antenna of photosystem I (PS I). Cells grown under PS I-light developed relatively high PS II/PS I and PBS/Chl ratios. Cells grown under PS II-light developed relatively low PS II/PS I and PBS/Chl ratios. Thus, the primary difference between cells in the two acclimation states appeared to be the relative concentration of PBS-PS II and PS I complexes in the thylakoid membrane. Measurements of the quantum yield of oxygen evolution suggested a higher efficiency of cellular photosynthesis upon the adjustment of photosystem stoichiometry to a specific light condition. The quantum yield of oxygen evolution was nevertheless lower under PBS than Chi excitation, suggesting quenching of excitation energy in the photochemical apparatus of PS II in Synechococcus 6301. This phenomenon was more pronounced in the PS II-light than in the PS I-light grown cells. Room temperature and 77 K fluorescence emission spectroscopy indicated that excess excitation energy in the PBS was not transferred to PS I, suggesting the operation of a non-radiative and non-photochemical decay of excitation energy at the PBS-PS II complex. This non-photochemical quenching was specific to conditions where excitation of PS II occurred in excess of its capacity for useful photochemistry.
HPLC-Determination of Apomorphine in a Mormyrid Fish, Gnathonemus petersii
Authors: Noe Angela , Kunze Peter 
Published: August 2018

Abstract
Uptake of apomorphine and elimination kinetics in brain and muscle tissue of the weakly electric fish Gnathonemus petersii (Mormyridae) was determined by HPLC. 20 min exposure of the fish to apomorphine in the aquarium water (0.4 mg/1) resulted in a concentration factor of 1.09 for brain and 0.55 for muscle tissue. Elimination from brain tissue can be described with first order kinetics (t1/2 = 2.4 h).
Modulation of Millisecond Chlorophyll Luminescence by Non-Photochemical Fluorescence Quenching
Authors: Bilger W. , Schreiber U. 
Published: August 2018

Abstract
By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring sys­tems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenching at photosystem II reaction centers, thus allowing determination of the non-photochemical quenching component. The saturation pulse induction curves of luminescence are well correlated with the corresponding curves of fluorescence, suggesting that luminescence yield is lowered by the same type of non-photochemical quenching (mostly “energy dependent quenching”) as fluorescence. Hence, in order to evaluate luminescence signals in terms of the rate of charge recombination at photosystem II reaction centers, knowledge of fluorescence quenching is required.
Immunological Identification of Polypeptides in Photosystem II Complexes from the Cyanobacterium Anacystis nidulans
Authors: Gau Achim E. , Wälzlein Gudrun , Gärtner Susanne , Kuhlmann Matthias , Specht Susanne , Pistorius Elfriede K. 
Published: August 2018

Abstract
Photosystem II complexes from the cyanobacterium Anacystis nidulans have been investigated by Western blots with antisera raised against four photosystem II peptides from plants and with an antiserum raised against the soluble L-amino acid oxidase protein from/1. nidulans to achieve an iden­tification of the polypeptides - especially of the L-amino acid oxidase related protein - in isolated photosystem II complexes. Anacystis photosystem II complexes which were solubilized with lauryldimethylamine N-oxide and purified by sucrose cushion and sucrose gradient centrifugation, contained as major Coomassie brilliant blue stained polypeptides a 71 kDa band of unknown identity, a 62 kDa band, which partly contained D-l, a 55 and 49 kDa band which were immuno-reactive with an antiserum to the 47 kDa peptide of tobacco PS II complexes, and three distinct bands in the 30 kDa region. These latter bands could be identified as the extrinsic Mn stabilizing peptide (27-30 kDa), D-l (30-33 kDa) and a 36 kDa peptide (35 - 38 kDa) which crossreacted with the antiserum raised against the soluble L-amino acid oxidase protein of 50 kDa. These results suggest that the 36 kDa peptide present in purified photosystem II complexes from A. nidulans might be a processed form of the soluble 50 kDa L-amino acid oxidase protein.
New Dihydrobiflavones from the Moss Plagiomnium cuspidatum
Authors: Anhut Siegbert , Seeger Tassilo , Zinsmeister H .-Dietmar , Geiger Hans 
Published: August 2018

Abstract
In Plagiomnium cuspidatum the three new dihydrobiflavones 2,3-dihydro-5′-hydroxyam entoflavone, 2,3-dihydro-5′,3‴-dihydroxyamentoflavone and 2,3-dihydro-5′-hydroxyrobustaflavone were detected.