bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding of Antibodies onto the Thylakoid Membrane. VI. Asymmetric Distribution of Lipids and Proteins in the Thylakoid Membrane
Authors: Radunz Alfons 
Published: August 2018

The maximal binding of antibodies out of monospecific antisera to proteins and lipids onto three different chloroplast preparations is compared. In these preparations different parts of the thylakoid membrane surface are accessible to antibodies. Whereas stroma-freed chloroplasts bind antibodies only at the outer surface, also the inner membrane surface is exposed in the two chloroplast preparations which were obtained by ultrasonication and subsequent fractionating centrifugation. In the ultrasonic sediment the inner surface is prevailing. In the ultrasonic supernatant antibodies do not only react with the inner and outer surface but also with con­siderable parties of the interior of the thylakoid membrane.
It was found that the thylakoid membrane surface exposed to the stroma consists preponder­antly of proteins whereas the surface directed towards the interior of the thylakoids consists mainly of lipids. All proteins involved in electron transport such as ferredoxin, ferredoxin- NADP+-reductase, plastocyanin, cytochrome f and the coupling factor of photophosphorylation are detectable in the outer surface. The molecules of the coupling factor span the thylakoid membrane from the outside to the inside. They hinder the binding of antibodies to mono- galactosyl diglyceride and to a polypeptide with the apparent molecular weight 24000. The polypeptide 24000 is a major component of the membrane proteins, and is detected on the outer and inner surface of the membrane. The major part of this polypeptide, however, is located in the interior of the thylakoid membrane.
The lipid mixture has a different composition in the outer surface than on the inside face of the membrane. The sulfoquinovosyl diglyceride and the phosphatides, phosphatidyl glycerol, phosphatidyl cholin and phosphatidyl inositol are stronger concentrated in the outer surface than in the inside face. The neutral monogalactosyl diglyceride and di- or trigalactosyl diglyceride, however, occur in the inner surface in higher concentrations than in the outer surface. The major part of the sulfoquinovosyl diglyceride and of the monogalactosyl diglyceride are located in the interior of the membrane.
Pyrophosphat-abhängige ᴅ-Fructose-6-phosphat Phosphotransferase in Rhodospirillaceae / Pyrophosphate-Dependent ᴅ-Fructose-6-phosphate-Phosphotransferase in Rhodospirillaceae
Authors: Pfleiderer Cornelia , Klemme Jobst-Heinrich 
Published: August 2018

Abstract
A pyrophosphate-dependent fructose-6 -phosphate phosphotransferase from the photosynthetic bacterium Rhodospirillum rubrum was partially purified and characterized in respect to kinetic and regulatory properties. The enzyme had a molecular weight of about 95 000 dalton and required Mg2+ -ions for catalysis and maintenance of activity. The phosphotransferase was specific for fructose-6 -phosphate (F-6 -P) and inorganic pyrophosphate (PP) as substrates of the fructose-1,6 -bisphosphate-forming reaction (forward reaction). In the phosphate (PO-dependent back reaction, the preferred substrate was fructose-1,6-bisphosphate (FBP). At optimal pH (7.2 for the forward, and 8.6 for the back reaction) the back reaction had a slightly higher Ʋmax than the forward reaction. The substrate-saturation curves of the enzyme were all hyperbolic with intersecting kinetic pattern. The Km-values (in mᴍ) at saturating MgCl2-concentration were: 0.38 (F-6-P); 0.025 (PP); 0.02 (FBP) and 0.82 (Pi). The forward reaction was inhibited by ADP and AMP. The inhibition by ADP (Ki = 0.18 mᴍ) was of the mixed type in respect to F-6-P, but independent of the PP-concentration. The inhibition by AMP (Ki = 0.017 mᴍ) was of a more complex type, because AMP not only decreased the Ʋmax of the F-6-P-or PP-saturation curve, but also increased the Hill-coefficient from nH = 1 to nH = 2.5 of the F-6-P-saturation curve. The inhibition of the back reaction by the two adenylates was less pronounced. ATP (at 2.5 mᴍ), like citrate, inhibited the back reaction only at low MgCl2 concentration (1 mᴍ) indicating that the inhibitory effect was due to the chela­tion of Mg2+. Out of 5 other species of the Rhodospirillaceae tested, the PP-dependent phospho-fructokinase was only shown to be present in Rhodopseudomonas gelatinosa.
Minor Phenolic Constituents of Grevillea robusta and Hakea saligna
Authors: Varma Manju , Varma R. S. , Parthasarathy M. R. 
Published: August 2018

Abstract
Three hitherto unknown phenolic constituents epilyoni-resinol, its glucoside and rhamnocitrin-3-O-rutinoside have been isolated from G. robusta wood and leaves besides kaempferol-3-O-rutinoside whereas 2,6-dimethoxybenzo-quinone, lyoniresinol and its rhamnoside are obtained from H. saligna wood. Their structures were assigned on the basis of chemical and spectral evidence.
Immobilization of Human Red Blood Cells
Authors: Pilwat Günter , Washausen Peter , Klein Joachim , Zimmermann Ulrich 
Published: August 2018

Abstract
Human red blood cells were immobilized in an alginate network which was cross-linked with Ca2+ ions. The immobilized cells were stored for longer than 5 weeks at 4 °C in an isotonic buffered NaCl solution containing glucose, inosine, adenine, and guanosine for energy supply. The immobilized cells were released from the alginate network by dissolving the matrix with citrate. Both the immobilized and released cells retain their biconcave shape over the storage period. Measurements of the released cell population in a hydrodynamically focussing Coulter Counter demonstrated that the mean size of the size distribution, the breakdown voltage, and the internal conductivity have not changed in contrast to control measurements on red blood cells stored conventionally in suspension indicating that immobilization preserves cellular functions.
Circular Dichroism of C-Phycoerythrin: A Conformational Analysis
Authors: Langer Elisabeth , Lehner Harald , Rüdiger Wolfhart , Zickendraht-Wendelstadt Barbara 
Published: August 2018

Abstract
An extensive study of the chiroptical properties of C-phycoerythrin and the α-and β-subunits in the spectral region from 700 -200 nm is presented.
Based on the VIS-circular dichroism inherently chiral conform ations are proposed for the co­ valently linked chromophores.
By means of mean residue ellipticities and the experimental circular dichroism spectra in the region of the n → π* peptide transition the a-helix contents of the apoproteins of the ac-and ß-subunits are estimated to amount to 60% and 40%, respectively. The circular dichroism spectrum of native C-phycoerythrin is congruent with a linear superposition of the α-and β-subspectra, in the whole spectral region studied. Since a-and β-subunits are associated in native C-phycoery-thrin as revealed by sedim entation analysis the interactions between the subunits in the native chromoprotein are not accom panied by substantial conform ational changes. In the temperature range 0°-40°C the thermally induced changes of the chrom ophores in native C-phycoerythrin are not associated with changes of the secondary structure of the apoprotein. Unfolding occurs at 60°-70°C but slowly leads to irreversible denaturation.
Protein unfolding starts at 3 M urea. The random coil secondary structure of the apoproteins is reached at 8 M urea. At this concentration the absorbance and the optical activity of the chrom o­ phores are reduced by a factor 3 and 10, respectively. The conformational changes in the peptide with increasing denaturant concentration are not synchronous with those induced in the Chromo­ phore indicating that a m ultistep process is operative during unfolding. The C D results on dena­ turation are supplem ented by absorption and em ission spectroscopy.
Fluorescence and Photochemical Properties of Plants with Defective Photosystem II
Authors: Menke Wilhelm , Schmid Georg H. 
Published: August 2018

Abstract
The mykotrophic orchid Neottia nidus-avis does not evolve oxygen in the light but is able to perform photophosphorylation. The low temperature fluorescence emission spectrum lacks the 680 and 690 nm bands. Hence, the spectroscopic chlorophyll a forms which are attributed to photosystem II do not occur in plastids of this orchid. The low temperature excitation spectrum of photosystem I fluorescence exhibits a maximum at 666 nm. The position of this maximum appears not to be influenced by energy transfer and corresponds to the absorption maximum of the chlorophyll form which emits the photosystem I fluorescence. Energy migration, however, occurs from carotenoids whose absorption spectrum is shifted to longer wavelengths and which cause the yellow-brown color of the Neottia plastids. Room temperature fluorescence emission shows after the onset of light no variable part.
Despite the fact that plastids of the tobacco mutant NC 95 at most evolve only traces of oxygen the low temperature emission spectrum shows the three bands which are usually observed with fully functioning chloroplasts. However, the two bands at 680 and 690 nm are distinctly lower than with the wild type. The variable portion of room temperature fluorescence is barely detectable. In line with the very low capacity for oxygen evolution, rates of electron transport partial reactions in the region of photosystem II are extremely low. In agreement with this observation no 690 nm absorption change signal is detected. However, a normal P+700 signal is seen. In the presence of electron donors like reduced phenazine methosulfate the decay time of the P+700 signal is faster than with the wild type.
The yellow tobacco mutant Su/su var. aurea which exhibits at high light intensities higher rates of photosynthesis than the wild type shows at low temperature an emission spectrum with stronger photosystem II bands than the wild type.
Further Oxygenated Compounds in the Essential Oil of Cistus ladanifer L. (Cistaceae)
Authors: Proksch Peter , Gülz Paul-Gerhard 
Published: August 2018

Abstract
Benzyl benzoate, cis-ocimenone and a new acetophenone derivative, 2-hydroxy-6-methyl acetophone, could be isolated by chromatographic methods from the essential oil of Cistus ladanifer. Structural elucidation by NMR and MS are described. In addition pinocarvone, campholene alde­hyde and tagetone were identified by their mass spectra.
Chlorophyll-Protein Complexes of Chlorella fusca
Authors: Wild Aloysius , Urschel Barbara 
Published: August 2018

Chlorophyll-protein complexes from thylakoids of the normal type and two mutants of Chlorella fusca were separated using sodium dodecyl sulfate acrylamide gel electrophoresis (PAGE). The properties of the chlorophyll-protein complexes of the three strains of Chlorella were compared. Standard curves were set up for the characterization of the chlorophyll-proteins. In every electrophoretic separation of chlorophyll-protein complexes, a certain amount of pigment is separated from the protein. We tried to keep that amount as low as possible by mild solubiliza­tion and by working in low temperature. Under these conditions, we obtained several new chlorophyll-proteins in addition to the P-700-chlorophyll a-protein (CP I) and the light-harvesting chlorophyll a/b-protein (CP II).
Thus, a small band (CP I a) was located between the top of the gel and the CPI after elec­trophoresis. Although it shows spectral qualities similar to CP I, it possesses a much lower chloro­phyll a/chlorophyll b ratio. It may be an aggregate of photosystem I and light-harvesting chloro­phyll.
We found and analyzed three other chlorophyll-proteins with electrophoretic mobilities inter­mediate between that of the P-700-chlorophyll a-protein and that of the light-harvesting chloro­phyll a/b-protein complex. Two of these chlorophyll-proteins, the LHCP1 and the LHCP2, have a low chlorophyll a/chlorophyll b ratio and spectral properties similar to that of the light-harvesting chlorophyll a/b-protein (LHCP3). They obviously represent dimers or oligomers of the latter com­plex.
A third, new complex (CPa) migrated between LHCP3 and its dimer. With the chlorophyll b deficient mutant G 36 of Chlorella fusca, this complex could be obtained in high purity and great enrichment (15% of total chlorophyll). It could be proved that this complex only contains chloro­phyll a. Its red absorption maximum is at 671 nm. Some indirect evidences suggest that it may be a good candidate for the PS II reaction center complex.
Anthocyanin Biosynthesis in Flowers of Matthiola incana Flavanone 3-and Flavonoid 3′-Hydroxylases
Authors: Forkmann G. , Heller W. , Grisebach H. 
Published: August 2018

Abstract
Enzyme preparations from flowers of defined genotypes of Matthiola incana contain two dif­ ferent hydroxylases for hydroxylation of naringenin in the 3-and 3′-position, respectively. The 3-hydroxylase is a soluble enzyme and requires as cofactors 2-oxoglutarate, Fe2+ and ascorbate. Besides naringenin eriodictyol is a substrate for the 3-hydroxylase. The 3′-hydroxylase is localized in the microsomal fraction and requires NADPH as cofactor. Naringenin and dihydro-kaempferol but not 4-coumarate or 4-coumaroyl-CoA are substrates for this enzyme. 3′-Hydroxylase activity is present only in genetic lines of M. incana with the wild-type allele b+.
Screening for Mutants of Rhizobium japonicum with Defects in Nitrogen Fixing Ability
Authors: Horcher Renate , Wilcockson John , Werner Dietrich 
Published: August 2018

Abstract
Mutants of Rhizobium japonicum with reduced ex planta nitrogenase activity could be isolated with high frequency by direct screening of ultra-violet mutagenized bacteria growing as spots on the surface of an appropriate agar medium permitting derepression of nitrogenase synthesis. Small glass chambers fitted with a serum cap were pushed into the agar around each spot of growth, forming a small enclosed gas space which was made to 10% acetylene, permitting assessment of nitrogenase activity by the acetylene reduction test. Four mutants were isolated from a total of 305 screened spots. Two mutants had almost no ex planta activity, one of which had no symbiotic activity despite normal nodulation (ineffective), the other had only somewhat reduced activity symbiotically. Two other mutants with less than half wild-type activity ex planta were normal in symbiosis.
Deoxyribonucleases in Herpes simplex Virus Type 1 and 2 Infected Primary Rabbit Kidney Cells
Authors: Zöllner E. Jürgen , Zahn Rudolf K. , Falke Dietrich 
Published: August 2018

Abstract
In primary rabbit kidney cells infected with herpes simplex virus four different neutral deoxyribonuclease activities can be detected by means of the deoxyribonuclease assay in DNA-containing polyacrylamide gels following their separation by discelectrophoresis. The method is suitable to follow independently the change in each activity of the different enzymes using only about 5 × 105 cells for each assay during the time-course of infection. Under these conditions one enzyme activity is constant, two disappear while the activity of a fourth one present only in infected cells, increases.
Cham onixin und Involutin, zwei chemosystematisch interessante Cyclopentandione aus Gyrodon lividus (B oletales) [1] / Chamonixin and Involutin, two Chemosystematically Interesting Cyclopentanediones from Gyrodon lividus (Boletales) [1]
Authors: Besl Helmut , Bresinsky Andreas , Herrmann Rupert , Steglich Wolfgang 
Published: August 2018

Abstract
The sporophores of Gyrodon lividus contain (-)-cha-monixin and (-)-involutin, indicating the close relationship of Gyrodon to the Paxillaceae and Gyroporus.
Accum ulation and Conversion o f 3-O -M ethyl-D -G lucose in Guard Cells o f Commelina communis L
Authors: Dittrich Peter , Fischer Klaus 
Published: August 2018

Abstract
Young plants of Commelina communis L. were allowed to take up [U-14C]-3-O-methyl-D-glucose through the cut stem via the transpiration stream. The distribution of this tracer carbohydrate in the plant was analyzed and its ac­ cumulation investigated in the epidermal tissue by micro­ autoradiography. Over feeding periods from 1 to 24 h 3-O-methyl-D-glucose accumulated predominantly in the guard cells of the stomata, whereas the other epidermal cells contained only minor amounts. Thus, guard cells, despite of the lack of plasmodesmata and the photosynthetic carbon reduction cycle, can easily obtain the carbohydrates from photosynthetic tissues necessary to drive the turgor mechanism of opening and closing. Depending upon the part of the plant, 3-O-methyl-D-glucose was converted during a period of 4 h up to 30% to the corresponding 6-phosphate despite the alledged inert nature in metabo­ lism of this artificial carbohydrate.
Paramagnetic Changes in Pulmonary Tumors
Authors: Lohmann Wolfgang , Bensch Klaus G. , Schreiber Jörg , Müller Elisabeth , Schwemmle Konrad , Feustel Herbert , Filler Rolf-Dieter 
Published: August 2018

Abstract
Electron spin resonance studies on healthy and tumerous human lung samples have been con­ducted in order to determine possible differences in free radical concentration and shape of the spectra between the different sections of the lung. It could be shown that in healthy lung tissue the signal caused by the sem idehydroascorbate (SDA) radical is not prominent because of the prevailing high partial oxygen pressure. On formation of a tumor, the spin concentration increases, possibly due to the higher metabolic rate; here, the SDA peak is also more pronounced which indicates alterations in the interaction between cell constituents and ascorbic acid. Within the tumor, the spin concentration is considerably reduced which is probably caused by a still higher concentration of ascorbic acid. Addition of ascorbic acid to the different lung specimens enhanced the just described effect while oxidizing substances, such as H2O2, reversed it.
Enzymatische Darstellung und Eigenschaften einiger Desulfoglucosinolate / Enzymatic Preparation and Properties of Some Desulfoglucosinolates
Authors: Rakow Dagmar , Gmelin Rolf , Thies Werner 
Published: August 2018

Abstract
10 different desulfo-glucosinolates belonging to 9 different homologous series have been isolated from the parent glucosinolates by means of a glucosinolate sulfohydrolase from the edible snail Helix pomatia. They were characterized by the following physical-chemical data: molecular weight, melting point, wavelength of the absorption maximum in the UV-region, molar absorption coefficient at this maximum, angle of optical rotation and Rf-values (thin layer and paper chromatography).
Purification of Chalcone Synthase from Tulip Anthers and Comparison with the Synthase from Cosmos Petals
Authors: Sütfeld Rainer , Wiermann Rolf 
Published: August 2018

Abstract
Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.
Esterification of Chlorophyllide in Prolamellar Body (PLB) and Prothylakoid (PT) Fractions from Avena sativa Etioplasts
Authors: Lütz Cornelius , Benz Jürgen , Rüdiger Wolfhart 
Published: August 2018

Abstract
Etioplast membranes were fractionated into enriched prothylakoid (PT) and prolamellar body fraction (PLB) by known procedures [2]. The photoconversion of Protochlide to Chlide was 77% in the PT fraction but only 65% in the PLB fraction with optimum NADPH concentrations. The subsequent esterification reaction proceeds in both fractions indicating that the enzyme chlorophyll synthetase is present in both fractions. In the PLB fraction, 10-15% more ChlP is formed than in the PT fraction. It is concluded that the concentration of the endogenous phytol precursor is higher in the membranes still present in the PLB fraction than in the PT fraction.
Specific Positional Distribution of Acyl Moieties in Phospholipids is not Generally Deleted in Neoplastic Cells
Authors: Weber N. , Wayss K. , Volm M. , Kiew Irmgard , Mukherjee K. D . 
Published: August 2018

Abstract
The distribution of acyl moieties at sn-1 and sn-2 positions of cholinephosphoglycerides (CPG) and ethanolaminephosphoglycerides (EPG) has been determined for neurosarcoma, sarcoma 180 and leukemia L 1210. In all the three samples, the positional distribution of acyl moieties in the two major classes of phospholipids is found to be similar to that in cellular phospholipids of most mammalian tissues. The saturated acyl moieties are located predominantly at sn-1 and polyunsaturated acyl moieties at sn-2, whereas the monounsaturated acyl moieties are randomly distributed between these two positions. Apparently, a disruption of specific positioning of acyl moieties in phospholipids, which hitherto has been considered to be a general metabolic deletion in neoplasia, does not exist in all neoplastic cells.
Oviposition Deterrance Activity in Some Lamiaceae Plants against Some Insect Pests
Authors: Sharma R. N. , Joshi Vijaya , Zadu Geeta , Bhosale A. S. , Gupta A. S. , Patwardhan Sarita , Nanda B. 
Published: August 2018

Abstract
Acetone extracts of 9 out of 12 plants of Lamiaceae family exhibited high oviposition deterrance (OD) activity against the potato tuber moth, P. operculella (PTM) 4 of these completely prevented egg laying by the latter and A. aegypti. In case of PTM this activity persisted for a varying number of days. 3 of them were also active against D. koenigii and M. domestica. None of the active extracts showed significant antifeedant or repellent activity against any pest species except D. koenigii. It was concluded that except in the case of the latter, the OD activity exhibited was not a corollary of antifeedant or repellent action, as is usually presumed. Magnitude and persistence of OD activity of at least one plant extract against the PTM was considered sufficient for employment in insectistatic management of this pest.
Synthese von Blepharismon, dem niedermolekularen Konjugationshormon von Blepharisma japonicum / Synthesis of Blepharismone, the Low-Molecular Conjugation Hormone of Blepharisma japonicum
Authors: Entzeroth Michael , Jaenicke Lothar 
Published: August 2018

Abstract
An effective and versatile synthesis of 5-hydroxytrypto-phane derivatives offers good access to the conjugation in­ducing hormone blepharismone of the ciliate Blepharisma japonicum and to derivatives and analogues of this biolog­ically active compound. 5′-Fluoroblepharismone and 2′-des-formamidoblepharismone induce conjugation at 500 and 1200 times, respectively, the concentration of the true effector. At high concentration, however, the 2′-des-formamido derivative desensitizes the receptor system for the natural gamone.