bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and Characterization of a 3,17 β-Hydroxysteroid Dehydrogenase from Streptomyces hydrogenans
Authors: Duchmann Helmut , Träger Lothar
Published: August 2018

3,17 β-Hydroxysteroid dehydrogenase has been enriched and purified from cytosol of Streptomyces hydrogenans. After ammonium sulfate precipitation and filtration on Sephadex G-100 the enzyme was finally purified by preparative gel electrophoresis and DEAE-Sephadex A-50 chro­matography. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate gave a single band of mobility corresponding to molecular weight of 70 200 ± 2 500. 3 β-. 17 β- as well as 20 β-hydroxy steroids were dehydrogenated by the enzyme in the presence of NAD+. The dehydrogenation proceeded faster than the reduction of the corresponding ketosteroids in the presence of NADH. The enzyme does not accent NADP+ or NADPH as co-substrates. The apparent Km values were calculated to be 11 μᴍ for 5 α-dihydrotestosterone, 20 μᴍ for testosterone ana 68 μᴍ for epiandrosterone in the NAD+-driven reaction, 1.8 x 10-4 m for NADH+ and 1.9 x 10-4 ᴍ for NADH. The catalytic activity was influenced by the ratio of NAD+/ATP. The inhibition by ATP appears to be of a competitive type with respect to NAD+ (Ki 1.15 x 10-3 ᴍ).

After sucrose gradient centrifugation in a preparative ultracentrifuge the enzyme sediments with 4.1 ± 0.1 S as estimated in comparison to other proteins of known sedimentation coefficient. The isoelectric point was determined to be 3.9 with the LKB preparative isoelectric focusing col­umn (pH 2-11) and 4.1 with the analytical flat bed polyacrylamide isofocusing (pH 3 - 5). The number of SH groups was determined to be 2 mol/mol enzyme. In the presence of 6 M urea the fig­ure inceases to 3 mol SH/mol enzyme. In the presence of an excess of p-chloromercuribenzoate the enzyme activity decreases only partially.
On the Possible Involvement of Ascorbic Acid and Copper Proteins in Leukemia. IV. ESR Investigations on the Interaction between Ascorbic Acid and Some Copper Proteins
Authors: Lohmann Wolfgang , Schreiber Jörg , Greulich Walter
Published: August 2018

The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceruloplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spec­troscopy. The spectra obtained are identical to the one obtained with leukemic blood. The consequences of this for the molecular events occuring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as reconsile the two existing and seemingly contradictory hypothesis. Possible implications for lipid peroxidation and for the respiratory process are discussed.
A Deterministic Model for Measles
Authors: Cunningham John
Published: August 2018

A deterministic model of recurrent epidemics is con­structed using a non linear relationship between infection rate and number of contacts. Epidemic waves which are not damped are predicted and a relationship between community size and the period of recurrence is established. A pos­sible explanation of measles outbreaks is suggested.
A Theoretical Study of H3PO4, nor-N-Mustard, and Cyclophosphamide
Authors: Ulmer W.
Published: August 2018

Some physical and chemical properties of the cancerostat cyclophosphamide (generic name: ENDOXAN) and its basic constituents H3PO4 and nor-N-mustard have been calculated with the help of a modified CNDO/S-method. The spectroscopic data of the H3PO4 , which is the starting-point for a corresponding calculation of cyclophosphamide, has been studied by taking account of the 3 d electron of the phosphorus. Nor-N-mustard is a very reactive compound, characterized by the ability to split off chloride ions and to act as an alkylating agent. The binding of the nor-N-mustard to the cyclic phosphate ester (cyclophosphamide) modifies the chemical reactivity of the mustard group in an essential way, and the 3d electron of the phosphorus plays an important role with respect to the excitability of the C -Cl bonds. Cyclophosphamide must be metabolized in a suitable way to develop the same alkylating activity as the nor-N-mustard. The computation of the excited states of cyclophosphamide revealed a similar term scheme as it was found by Clar in the case of the carcinogenic polycyclic hydrocarbons.
A Spectroscopic Study on p-Hydroxyphenylpyruvic Acid. Keto-Enol Tautomerism and Stability of Its Complex with Fe+3 Ions
Authors: Cassidei L. , Dell’Atti A. , Sciacovelli O.
Published: August 2018

1H-, 13C -NMR , IR, UV-Vis, and MS spectra of p-hydroxyphenylpyruvic acid (pH PPA) have been recorded and fully interpreted.

pHPPA exists in solution as a mixture of interconverting forms: keto, hydrated keto and only one enol tautomer to which the Z configuration has been assigned according to the value (3.7 Hz) of the vicinal IH-C = C-13COOH coupling constant.

In organic solvents the enol isomer is far more stable whereas in aqueous solutions the keto form predominates. The tautomeric equilibrium is pH-dependent and the anion is present as keto form not only in aqueous solution but also in H2O-DMSO mixtures with a high content of DMSO.

The Z enol tautomer does form a coloured complex (λmax = 680 nm) with Fe+3 ions. The complex decomposes rapidly in all considered solvents except DMSO.

In view of a possible use of H2O-DMSO mixtures for clinical analysis purpose, the enol fraction of pHPPA and the stability of the pH PPA -FeCl3 com plex in H2O-DMSÒ mixtures have been examined. Our results suggest that a solvent com position containing at least 80 vol.% in DM SO could be an appropriate solvent for pH PPA determination by FeCl3 method.
Identification of 4 Sex Pheromone Components Isolated from Calling Females of Mamestra brassicae
Authors: Struble D. L. , Arn H. , Buser H. R. , Städler E. , Freuler J.
Published: August 2018

Evidence obtained by glass capillary gas chromatography coupled to an electroantennographic detector or a mass spectrometer confirmed that Z-11-hexadecenyl acetate is the major component in the pheromone gland washes of calling Mamestra brassicae female moths. Three other components were identified, tetradecanyl acetate, hexadecanyl acetate and E-11-hexadecenyl acetate; but none of these had obvious synergistic effects in attracting males in field tests. The attraction of males to Z -11-hexadecenyl acetate was inhibited by 0.1% Z -11-hexadecenol or 1% Z-9- tetradecenyl acetate.
Cell Proliferation and Metabolism of Ehrlich Ascites Tumor Cells Grown in Chemically Defined Albumin Medium for Several Passages
Authors: Teschner Regina , Postius Stefan , Löffler Monika , Schneider Friedhelm
Published: August 2018

Cell proliferation, cell cycle distribution, viability, uptake of α-aminoisobutytic acid, cyclo leucine and 2-deoxyglucose as well as DNA, RNA and protein synthesis of Ehrlich ascites tumor cells grown in suspension culture over three passages in serum free nutrient medium supplemented with 1-2 % bovine serum albumin (Cohn fraction V, Serva) were measured and compared to cells grown in medium supplemented with 15% horse serum. At the end of the fourth passage in vitro, that is the third passage in serum free albumin medium, the growth of the cells is reduced to about 10% of the controls, accumulation of the cells in G 2 is delayed and the number of dead cells rises to 30%. The transport rates of α-aminoisobutyric acid and of 2-deoxyglucose slowly decrease while the up­ take of cycloleucine shows a more complex behaviour in albumin medium. Incorporation of thy­ midine and leucine into the cells corresponds to the growth rate, while the incorporation of uridi­ne in normal as well as in albumin medium exhibits different pattern. The present experiments demonstrate, that it may be possible to preserve this cells in a fairly “physiological” state during two passages in albumin medium.
Analysis of Sesquiterpene Lactones by High Performance Liquid Chromatography
Authors: Strack Dieter , Proksch Peter , Gülz Paul-Gerhard
Published: August 2018

High performance liquid chromatography on octyl- and octadecyl-silica (RP-8 and RP-18) stationary phases offers an efficient and rapid method for analysis of sesquiterpene lactones. A mixture of 11 lactones was analyzed using gradient elution with increasing acetonitrile concentra­tion in water and monitoring the column effluent at 210 nm with an UV detector. The described method has been applied to the determination of costunolide in a crude extract from leaves of Laurus nobilis.
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

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

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

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

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

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

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.
Methylmercury-Chromosome Interactions. I. Thermal Denaturation of Calf Thymus Chromatin in Presence of CH3HgOH
Authors: Otsuki Lauren G. , Gruenwedel Dieter W.
Published: August 2018

The effect of CH3HgOH on the thermal stability of calf thymus chromatin in Na2SO4 (10 mᴍ Na+, pH 6.8) has been studied spectrophotometrically by heat denaturation. From changes observed in the integral and differential melting profiles, gathered via absorbance measurements at 260 nm as a function of CH3HgOH concentration, it is concluded that methylmercury at low concentrations (1-10μᴍ), and prior to its denaturating the double-helix of the chromosomal DNA, interferes with the binding of DNA by histones H3 and H4 which is followed, at methyl- mercury concentrations between 10 and 32 μᴍ, also by its interfering with the complexing of DNA by the less basic histones H2A and H2B. DNA denaturation, in absence of the histones, proceeds only at methylmercury concentrations above 32 μᴍ under the experimental conditions given.
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

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

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

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

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

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

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.
Über die Eisenanaloga von Cobalamin und Cobyrsäure / About the Iron Analogues of Cobalamin and Cobyric Acid
Authors: Bieganowski Rainer , Friedrich Wilhelm
Published: August 2018

The reaction of hydrogenocobalamin or hydrogenocobyric acid (both isolated from Chromatium vinosum) with iron(III) acetate and iron powder in acetic acid under N2 at 80 °C leads to the incorporation of iron into these cobalt-free corrinoids. The products, Fe(III)cobalamin and Fe(III)cobyric acid, were separated by means of a column of Amberlite XAD-2. They have the electrophoretic mobility of the corresponding cobalt-corrinoids. The brown aqua-forms react with cyanide, rhodanide and azide, and can be reduced by means of NaBH4 to the green Fe(I) forms. The new compounds were analyzed and characterized by means of elemental analysis, paper chromatography, electrophoresis and spectra (UV/VIS, NMR, ESR).
Enzymatische Darstellung und Eigenschaften einiger Desulfoglucosinolate / Enzymatic Preparation and Properties of Some Desulfoglucosinolates
Authors: Rakow Dagmar , Gmelin Rolf , Thies Werner
Published: August 2018

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

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

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

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

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

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.
Biosynthesis of 3-Carboxy-6,7-dihydroxy-1, 2,3,4-tetra- hydroisoquinoline and 1-Methyl-3-carboxy-6,7-dihydroxy-1, 2,3,4- tetrahydroisoquinoline in a Callus Culture of Stizolobium hassjoo
Authors: Obata-Sasamoto Hamako , Komamine Atsushi , Saito Koshi
Published: August 2018

ᴅʟ-[β-14C] 3,4-Dihydroxyphenylalanine (DOPA), [2-14C]pyruvate and [2-14C]acetate were ad­ministered to a callus culture of S. hassjoo and incorporation of the radioactivity into 3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (I) and 1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (II) was examined. Incorporation of radioactivity from labelled DOPA into I and II, and from acetate into I were observed, while that from pyruvate into I and II and from acetate into II were hardly detected. The biosynthetic pathways of I and II were discussed.
Anthocyanin Carrying Structures in Specific Genotypes of Matthiola incana R. Br.
Authors: Hemleben V.
Published: August 2018

Several lines of the genetically well defined Matthiola incana (Brassicaceae) concerning the anthocyanin biosynthesis (line 02, 06, 10, and 14) store the anthocyanin pigment as crystals (line 06) or in anthocyanoblasts (“balls”) in the epidermal cells (line 02, 10, and 14) of the flower petals. The genetic constitution of these genotypes is in addition to the basic factors f+, g+, and e+, b+b+ or bb (cyanidin or pelargonidin type), ll, u+u+, and v+v+ or vv, demonstrating that the ll, u+u+ constitution is responsible for precipitation of anthocyanins in a certain structure indepen­ dent of the other modificationally acting genes b and v. The ll, u+u+ types accumulate preferentially acylated 3-biosides.
Regulation of the Synthesis of Ribulose-l,5-bisphosphate Carboxylase and Its Subunits in the Flagellate Chlorogonium elongatum. II. Coordinated Synthesis of the Large and Small Subunits
Authors: Westhoff Peter , Zimmermann Kurt , Boege Frank , Zetsche Klaus
Published: August 2018

Transfer of heterotrophically grown cells of the unicellular green alga Chlorogonium elongatum to autotrophic growth conditions causes a 10 -15 fold increase in the amount of the chloroplastic enzyme ribulose-1,5-bisphosphate carboxylase.

This increase was found to be due to de novo synthesis. The relative proportions of large and small subunits of the enzyme do not change. Their ratio is close to 3.4, the proportions in weight of the two subunits in the holoenzyme. Continous labelling with [35S]sulfate reveals that the ratios of incorporation into large and small subunits are essentially the same in autotrophic and heterotrophic cells.

Pulse-chase experiments show that the subunits are degraded synchronously.

The coordinated subunit synthesis cannot be uncoupled using inhibitors of protein and RNA synthesis or high temperature of cultivation of the alga.

The results suggests a very tightly coordinated synthesis of the large and small subunits of ribulosebisphosphate carboxylase.
Molecular Forms of Purified Cytoplasmatic and Membrane Bound Bovine-Brain-Acetylcholinesterase Solubilized by Different Methods
Authors: Rueß K.-P. , Liefländer M.
Published: August 2018

Membrane bound, Triton X-100 solubilized bovine nucleus caudatus acetylcholinesterase is sedimenting in presence of Triton X-100 concentrations higher than the CMC as a 10.5 S-detergent-enzyme complex. There is evidence that this complex does neither represent the molecular enzyme arrangement present in the membrane, nor the molecular form originally released from the membrane.

The purified, cytoplasmatic acetylcholinesterase is sedimenting as a 10.5 S-form too. This form is clearly to be distinguished from the detergent enzyme complex, for it is obviously not capable of aggregating, whereas the 10.5 S-detergent-enzyme complex aggregates on detergent removal to defined water soluble oligomers with sedimentation coefficients of 16 S (700000 ± 10000), 20.6 S (960000 ± 60000) and 23.3 S (~ 1200000). In contrast to acetylcholinesterase from erythrocytes this aggregation is not easily reversibly by incubation with Triton X-100, reflecting differences in the hydrophobic part of the enzymes.

Purified acetylcholinesterase solubilized without detergent under autolytic or tryptic conditions is mainly sedimenting as a 4.5 S-form. Such slow sedimenting forms detected in crude solubilisates of neuronal tissues, may originate at least partially form autolytic solubilization.
A Family of Sequences with Regional Homology to Bovine 1.715 Satellite DNA
Authors: Skowroński Jacek , Płucienniczak Andrzej
Published: August 2018

The organization of sequences homologous to the bovine 1.715 satellite DNA was studied in the bovine genome. A novel family of sequences, containing different numbers of copies of the 1.4 kb satellite period alternating with 1.2 kb sequence not related to this satellite, was found. Possible mechanism of the generation of these sequences is proposed.
Partial Denaturation Mapping of Phage T4 DNA at Low Temperature
Authors: Grossi G. F. , Macchiato M. F. , Gialanella G.
Published: August 2018

The partial-denaturation map of T4 DNA is obtained by using benzyldodecyldimethyl ammonium chloride in the presence of a high concentration of formamide. In this way suitable conditions for preparation of electron microscope specimens and partial denaturation within a temperature range low enough to minimize the endonucleolytic cleavage, are realized.

It is found that, under our experimental conditions, the denaturation increase depends mainly on the appearance of new denaturation sites rather than on the lengthening of DNA segments already denatured.

Because of the DNA circular permutation it is necessary to align the measured maps to obtain the denaturation pattern. This is done through a computer program and informations on the distribution of the regions with highest (A-T) content along the genome are obtained.

The results of contour length measurements of λ and T4 DNA’s are also reported.
Effects of Linolenic Acid on the Spectral Properties and Picosecond Fluorescence of Pea Chloroplasts
Authors: Brody S. S. , Barber J. , Tredwell C. , Beddard G.
Published: August 2018

Linolenic acid induces changes in the absorption spectrum and in the picosecond fluorescence of pea chloroplasts. The effects of linolenic acid are dependent on concentration and time.

Linolenic acid increases the fluorescence life time of chloroplasts at room temperature. The contribution of the slow fluorescence component relative to the fast component is increased almost 10 fold in the presence of 0.5 mᴍ linolenic acid. The synergistic action of digitonin and linolenic acid increases the ratio of “closed” to “open” traps in the photosynthetic units.

Upon addition of 0.5 mᴍ linolenic acid there are increases in absorbance at 676 and 436 nm, and decreases in absorbance at 705 and 496 nm. Some of the spectral changes have a biphasic character, they reach a maxi um um after about 30 min then start to reverse. Based on the spectral changes at 496 and 705 nm it appears that linolenic acid has at least two effects, i.e. it modifies the thylakoid membrane and secondarily decreases the concentration of P700, respectively.
αβ-Dehydrocurvularin and Curvularin from Alternaria cinerariae
Authors: Robeson David J. , Strobel Gary A.
Published: August 2018

Secondary metabolite production by the phytopathogen Alternaria cinerariae has been investigated resulting in the isolation and identification of αβ-dehydrocurvularin and curvularin as products of this fungus. The phytotoxicity of these compounds is demonstrated.
Effects of Glyphosate on Shikimic Acid Accumulation in Tobacco Cell Cultures with Low and High Yields of Cinnamoyl Putrescines
Authors: Berlin Jochen , Witte Ludger
Published: August 2018

To study the flow of carbon through the shikimate pathway in tobacco cell cultures with low and high yields of cinnamoyl putrescines, the cell cultures were treated with glyphosate. In the presence of glyphosate the levels of free shikimic acid were increased more than 300-fold by both cell lines. Despite of a normally 10-fold higher level of cinnamoyl putrescines, the high yielding cell line accumulated only 25% more free shikimic acid than the low yielding cell line. This result together with earlier observations indicated that the increased formation of cinnamoyl putrescines was rather limited by the activity of phenylalanine ammonia lyase than by increased substrate supply caused by alterations in the shikimate pathway
Isolation of Nuclei from Crayfish Tissues and Demonstration of Nuclear Ecdysteroid Receptors
Authors: Spindler-Barth Margarethe , Bassemir Ursula , Kuppert Paul , Spindler Klaus-Dieter
Published: August 2018

Nuclei from hypodermis and midgut gland of the crayfish, Orconectes limosus, have been isolated with a slightly modified Chauveau-method. The isolated nuclei are well preserved and free from cytoplasmic contamination. They are able to incorporate [3H]UTP into acid-insoluble material. This labelling is α-amanitin sensitive. The isolated nuclei are devoid of the mitochondrial/microsomal ecdysone-C-20-hydroxylase. The DNA: RNA: protein ratio is 1:0.8: 3.2 (using Triton X-100 during the isolation procedure the ratio is 1:0.4: 4.6) for nuclei from the hypodermis and 1:1: 3.8 for nuclei from the midgut gland. The absolute amount of DNA per cell is 1.6, resp. 3.5 pg. The final DNA-recovery is about 20%. The yield increases to about 60% if the final ultrazentrifugation step is omitted. The isolated nuclei bind 3H-ecdysone and 3H-20-OH-ecdysone specifically. As revealed by Scatchard analysis the affinity of the nuclear 20-OH-ecdysone receptor is 1-2 × 10-9 ᴍ
Formation of fusaric acid by fungi of the genus fusarium
Authors: Mutert W.-U. , Lütfring H. , Barz W. , Strack D.
Published: August 2018

Among various Fusarium strains tested Gibberella fujikuroi (SAW) WR was shown to be a high producer of the phytotoxin fusaric acid
Effect of Glucocorticoids, Insulin and a Growth Promoting Tripeptide on the Biosynthesis of Plasma Proteins in Serum-Free Hepatocyte Cultures
Authors: Fouad Fouad M. , Abd-El-Fattah Mohamed , Scherer Reiner , Ruhenstroth-Bauer Gerhard
Published: August 2018

The effect of cortisol, dexamethasone, insulin and a liver cell growth promoting tripeptide on the secretion of plasma proteins into the medium of rat hepatocytes in monolayer cultures was studied. Cortisol and dexamethasone resulted in ~ 2.5-fold increase in the fibrinogen synthesis with general supression of album in and α-lipoprotein synthesis. On the other hand, insulin inhibited the biosynthesis of most plasma proteins except for the complement system and transferrin. Concentrations of α-lipoprotein, a-1-macroglobulin and haptoglobin were moderately elevated when the tripeptide Gly-His-Lys was applied in low concentration
Glucagon-Like Immunoreactivity (GLI) in Blood Plasma of Partially Hepatectomized Rats
Authors: Strecker W. , Ruhenstroth-Bauer G. , Böttger I. , Pabst H. W.
Published: August 2018

The concentration of substances with glucagon-like immunoreactivity (GLI) was determined in arterial blood plasma of rats up to 4 weeks after partial hepatectomy. 10 h following surgery a more than 18-fold increase in GLI + glucagon immunoreactivity could be observed. About 2/3 of the maximum activity seems to be of non pancreatic origin. The levels returned to normal about 22 h after surgery.
Action Potentials in "Non-Spiking" Visual Interneurones
Authors: Eckert Hendrick E. A. , Hamdorf Kurt
Published: August 2018

The response of the homolateral “horizontal cells” (H-cells) of the third visual neuropile of the blowfly, Phoenicia sericata, has been investigated by intracellular recordings coupled with dye injections (Procion Yellow, cobaltous chloride). Responses were obtained from their terminal axon endings in the central protocerebrum. Under natural conditions, the horizontal cells respond not with graded potentials as reported previously, but with action potentials upon stimulation by regressive pattern motion within the contralateral receptive field. The stimulus-induced responses change from action potentials to graded signals within a few minutes after opening the head capsule. The possible causes of this change, namely hypoxic conditions and a consequent depletion of the ATP-supply, are consistent with the experimental data: a change in the resting potential as well a reduction of the spike amplitude. Furthermore, the possibility of two functionally different output regions of the H-cells is discussed, namely, (1) the terminal axon endings appear to conduct action potentials induced by the contralateral input (to the H-cells). Thus, these endings provide a solely contralateral, i.e. “monocular output”. Whereas (2) the axonal arborisation appears to conduct graded signals elicited by the ipsilateral input onto which the contralateral input is superimposed, thus providing a “binocular output”.
Methylation of 3′,4′ Di-O H C-Glycosyl-flavones in Silene
Authors: Brederode Jan van , Kamps-Heinsbroek Ria
Published: August 2018

In green parts of Silene plants of the genotype glR two methylated flavonoids were found: isoscoparin and isosco-parin 2″-O-rhamnoside. An enzyme has been demonstrated to catalyze the transfer of the methyl moiety of S-adenosyl methionine to iso-orientin and iso-orientin 2″-O-rhamnosi-de. Maximal activity takes place at pH 8.0 -8 .2 . Of the metal ions Mn2+, Mg2+, Ca2+, Co2+, Zn2+ and Hg2+, only Co2+ stimulated the reaction at conc. > 2 mM . For the methyla­ tion of isoorientin the Km values were 4 × 10-6 M for S-ade-nosyl methionine and 0.32 × 10-3 m for iso-orientin. When isoorientin 2″-O-rhamnoside was used as substrate the Km values were 5 × 10-6 m for S-adenosylmethionine and 7 × 10-6 M for iso-orientin 2″-O-rhamnoside.