bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of Photosynthetic and Respiratory Electron Transport in Blue-Green Algae: Effect of a Cytochrome c-553 Specific Antibody
Authors: Alpes Irene , Stürzl Erwin , Scherer Siegfried , Böger Peter
Published: August 2018

An antibody prepared against purified cytochrome c-553 from Nostoc muscorum inhibits the redox function of cytochrome c-553 as checked by a diaphorase assay. 20 to 30% inhibition of NADPH-driven respiratory and light-induced oxygen uptake by Nostoc thylakoids is observed when cytochrome c-553 specific antibodies were applied. However, only 30 to 50% of the total cytochrome c-553 content is released from isolated membrane material, thus being accessible to antibodies. Supplementing the isolated membrane material with excess Nostoc cytochrome before adding the antibody abolishes inhibition. The data provide further evidence for soluble cytochrome c-553 being a link between photosynthetic and respiratory electron transport in blue- green algae.
Effect of UV-B Radiation on Biomass Production, Pigmentation and Protein Content of Marine Diatoms
Authors: Döhler Günter
Published: August 2018

Several species of marine diatoms were grown at + 18 °C and + 22 °C under normal air condi­tions (0.035 vol.% C02) at a light/dark alteration of 14: 8̄ h. Intensity of white light was 1 mW (~ 5000 lux). An artifical nutrient solution of 35%o salinity was used. Algae - harvested during exponential growth - were exposed to different intensities of UV-B radiation (439, 717 and 1230 J · m-2 · m-1) for 2 days. UV-B radiation depressed the growth of all tested marine diatoms. Low levels of UV-B resulted in a slight increase of the biomass production (dry weight) compared to not UV-B treated cells. Enhanced UV-B doses caused a diminution of the primary productivity in all species. Algae exposed to UV-B stress showed a marked decrease in the protein and pigment content (chlorophyll a, chlorophyll c1 + c2 and carotenoids). In + 22°C grown cells of Lauderia annulata and Thalassiosira rotula were more sensitive to UV-B radiation than those cultures grown at + 18 °C. Bellerochea yucatanensis cells grown at +22 °C were less affected after UV-B exposure than at +18°C grown algae. The UV-B sensibility and growth of the individual species varied in a mixture of several marine diatoms. Results were discussed with reference to the UV-B effect on metabolic processes.
Temperature Induced Spectral Changes of Chlorophyll in Micelles and Solution
Authors: Brody Seymour Steven
Published: August 2018

Effects of temperature on the spectral properties of chlorophyll in solution and in micelles are reported. After correcting for the volume expansion coefficient of the solvent, it is observed that temperature has no detectable effects on the spectral properties of chlorophyll (between 14 °C to 35 °C). Solutions examined include acetone, chloroform and ethyl alcohol. It is concluded that the temperature induced change in refractive index, of the solvent, has no significant affect on the chlorophyll spec­trum.

In micelles containing chlorophyll there are significant temperature induced spectral changes. Heating and cooling results in an irreversible redistribution of monomeric and oligomeric forms of chlorophyll.
Lamoxirene. Structural Proof of the Spermatozoid Releasing and Attracting Pheromone of Laminariales
Authors: Mamer F.-J.
Published: August 2018

Mature female gametes of several Laminariales excrete a substance which acts interspecifically to release and to attract spermatozoids from ripe antherids. This pheromone was identified by chemical degradation and by synthesis of the natural compound as 1-(1′,2′-cis-epoxi-but-3′-enyl)- cyclohepta-2,5-diene (3). An oxirane is a novel feature among the mating substances of thallophytes. It is there­fore suggested to name the active hormone “Lamoxirene”.
6-Hydroxyflavones and Other Flavonoids of Crocus
Authors: Harborne Jeffrey B. , Williams Christine A.
Published: August 2018

6-Hydroxyflavones have been identified for the first time in the Iridaceae, in leaves of three Crocus species. Three new glycosides have been characterised: 6 -hydroxyluteolin 7- rhamnosylglucoside, scutellarein 7-glucoside and scutellarein 7-methyl ether 6 -glucoside, as well as two known glycosides: 6 -hydroxyluteolin 7-glucoside and 6 -hydroxyluteolin 7-methyl ether 6 - glucoside. 6 -Hydroxyluteolin and scutellarein glycosides have been found before in Bromeliaceae. Commelinaceae, Cyperaceae and Orchidaceae, but this is the first record of the respective 7-methylethers in the Monocotyledoneae. Acacetin and tricin have been identified as aglycones in C. laevigatus an d C. heuffelianus leaves, respectively and the occurrence of mangiferin confirmed in C. aureus leaves. Two of the major flavonol glycosides present in flowers of cultivated species were identified as kaempferol 3-sophoroside and kaempferol 3- rutinoside-7-glucoside. However none of the flavonoids identified appears to contribute to yellow petal colour in Crocus, which is probably entirely carotenoid-based.
Aliphatic 1-Amino Acid Decarboxylase from Ferns (Filicopsida)
Authors: Hartmann Thomas , Bax Klaus , Scholz Renate
Published: August 2018

A screening of 27 fern species (Filicopsida) out of 9 families revealed that 25 species were able to decarboxylate 1-leucine to 3-methylbutylamine (isoamylamine). The enzyme of Polvpodium vulgäre has partially been purified and characterisized. All attempts to solubilize it from acetone preparations failed; however, approx. 50% of total activity could be extracted from dry material in the presence of detergents at high concentration. The soluble enzyme was purified 132-fold. 1-Methionine was found the best substrate followed by norvaline, leucine, norleucine, isoleucine, homocysteine, valine. It has been confirmed that these substrates are decarboxylated by a single enzyme. The pH -optimum was at pH 5.0 (particulate preparation) and pH 4.5 (soluble enzyme). Decarboxylation is dependent on pyridoxal-5′-phosphate (PLP). A strictly substrate dependent coenzyme dissociation was observed which could largely be prevented by addition of 2-oxo-acids, such as glyoxylate or pyruvate. A podecarboxylase prepared by prolonged substrate incubation was found to be extremely labile at pH 4.5 but stable at pH 6.5. A comparison of the fernenzyme with bacterial valine decarboxylase (EC 4.1.1.14) and leucine decarboxylase of red algae revealed great similarities especially in substrate specificity. It is suggested to unify these activities as “aliphatic 1-amino acid decarboxylase”.
Hormone Induced Changes in Carotenoid Composition in Ricinus Cell Cultures. I. Identification of Rhodoxanthin
Authors: Kayser Hartmut , Gemmrich Armin R.
Published: August 2018

When cell cultures of Ricinus communis are grown in light and with kinetin as the sole growth factor red cells are formed. The red pigmentation is due to the accumulation of rhodoxanthin which is the major carotenoid in these cultures. The identification of this retro-type carotenoid is based on electronic and mass spectra, on chemical transformation to zeaxanthin, and on comparison with an authentic sample. Rhodoxanthin is not present in any part of the intact plant. The major yellow carotenoid in the red cultures is lutein.
Purification and Partial Characterization of the Soluble NADH Dehydrogenase from the Phototrophic Bacterium Rhodopseudomonas capsulata
Authors: Ohshima Toshihisa , Ohshima Matsumi , Drews Gerhart
Published: August 2018

Soluble NADH dehydrogenase was purified to homogeneity from chemotrophically grown cells of Rhodopseudomonas capsulata by ammonium sulfate fractionation, AH -Sepharose 4B chromatography and FMN-Sepharose 6B affinity chromatography. The enzyme contains a single polypeptide chain of an apparent M, of 37000, suggesting that the subunit structure is different from that of the membrane-bound enzyme. The purified soluble NADH dehydrogenase requires flavin compounds, e.g., FMN, FAD and riboflavin, for activity. Addition of FMN and FAD. but not riboflavin, to the enzyme solution stabilized the enzyme. The pH optimum for activity was at 7.5. The enzyme was specific for NADH as an electron donor while NADPH was inert. Menadione, ferricyanide, cytochrome c and DCIP served as an electron acceptor. The M ichaelis constants for NADH. DCIP, FM N. and cytochrome c were 45, 2.9. 7.9 and 15 μM, respectively. Many properties of soluble NADH dehydrogenase were substantially different from those of the membrane-bound enzyme, suggesting different functions.
Light Dependent Ammonium Inhibition of Nitrate Assimilation in Rhodopseudomonas capsulata AD2
Authors: Alef Kassem
Published: August 2018

Nitrate assimilation by Rhodopseudomonas capsulata AD2 was completely inhibited by ammonium only in young well illuminated cultures. At higher densities (A660 about 0.5) the addition of ammonium had no inhibitory effect, but the nitrate was only reduced to the level of nitrite, which appeared in the medium. Under both conditions the cellular level of nitrate reductase activity remained unaffected. In marked contrast to other R. capsulata strains both ammonium sensitive and insensitive cells could reduce nitrate in the light and in the darkness. In the light up to 90% of the reduced nitrate was assimilated, but in the dark the reduced nitrate was stoichiometrically excreted as nitrite. This behaviour was only shown by R. capsulata AD2 and BK5, while in other strains the nitrate assimilation was always completely inhibited by ammonium.

The role of photosynthesis and respiration by the regulation of nitrate reduction is discussed.
Immune Serum against Anti-DNA-8-Methoxypsoralen Photoadduct
Authors: Zarębska Z. , Jarząbek-Chorzelska M. , Jabłońska S.
Published: August 2018

Specific immune serum against photo-damaged DNA with the photoadducts of 8 -methoxypsoralen (8-MOP) was obtained. The antigenic determinant is a polynucleotide chain with a mono-photoadduct: a coumarin moiety of psoralen linked through a cyclobutane ring to the 5,6-bond of thymine. The specific rabbit antiserum was used in the immunofluorescence method, for the detection of photodamaged DNA in the kinetoplasts and nuclei of unicellular organisms Crithidia luciliae, in the nuclei of snap-frozen tissue of mammals, and in human blood lymphocytes. Detection by the immunofluorescence method was limited by psoralen availability in situ; the psoralen concentration should be in the range 0.05 -0.2 μg/cm2 on specimens submitted to a topical application or about 1 μg/ml in cell suspension. The long-wave ultraviolet light (UV-A) exposure dose applied to the nuclei should exceed 1J/cm2.
X-Ray Studies on Phospholipid Bilayers, in. Structure and Morphology of L-α-Dilaurylphosphatidylethanolamine (DLPE)
Authors: Suwalsky M. , Seguel C.G. , Neira F.
Published: August 2018

Phospholipid, Bilayer, X-Ray Diffraction, Morphology, Dilaurylphosphatidylethanolam ine, Membrane Powder samples and oriented films of the synthetic phospholipid L-α-dilaurylphosphatidyl-ethanolamine (DLPE) were studied by X-ray diffraction over a wide range of hydration. Only small differences were found between the unit cell dimensions of DLPE powder and oriented-film specimens. These dimensions did not vary appreciably with hydration. In the multilayer DLPE structure, the molecules pack with polar groups parallel to the bilayer plane and hydro­ carbon chains perpendicular to it. Examination of oriented films by scanning electron microscopy gave information on the surface morphology. Complementary data on the lamellar packing of the molecules and the average thickness of the bilayers was provided by thin-section and shadow-cast preparations studied by transmission electron microscopy.
New Cinnamoyl Esters of Quinic Acid from Meumathamanticum
Authors: Barron Denis , Kaouadji Mourad , Mariotte Anne-Marie
Published: August 2018

Two new cinnamoyl quinic acid esters were isolated from the methanolic extract of Meumathamanticum rhizome. They were identified as l-trans-O-caffeoyl quinic acid methyl ester and l-trans-O-feruloyl quinic acid methyl ester by the spectral data of the natural products and those of the acetylated derivatives.
Salmonella/ Microsome Mutagenicity of 1-Nitropyrene-2-ol, a Nitropyrene Phenol Formed in the Photolysis of 1-Nitropyrene
Authors: Löfroth Göran , Nilsson Lena , Agurell Eva , Yasuhara Akio
Published: August 2018

1-Nitropyrene-2-ol is not detectably mutagenic in the Salmonella test in the absence of mammalian activation. It is activated by the rat liver microsom e-containing preparation S9 and gives a mutagenic response similar to that of benzo(a)pyrene.
Constituents of Agaricus xanthodermus Genevier: The First Naturally Endogenous Azo Compound and Toxic Phenolic Metabolites
Authors: Gill Melvyn , Strauch Richard J.
Published: August 2018

Extraction of fresh sporophores of the fungus Agaricus xanthodermus yields 4,4′-dihydroxy-azobenzene, phenol, p-quinol, and 4,4′-dihydroxybiphenyl. This is the first report of an azo compound arising endogenously in nature, while phenol, p-quinol and 4,4′-dihydroxybiphenyl have not previously been isolated from higher fungi. Phenol is present in fruitbodies in sufficiently high concentration to account for the toxicity of A. xanthodermus.
Flash Pattern of Oxygen Evolution in Greening Etioplasts of Oat
Authors: Franck Fabrice , Schmid Georg H.
Published: August 2018

Etioplasts isolated from oat leaves that have received two 5 min illumination periods, spaced apart by a 90 min dark interval, are able to evolve oxygen. If this oxygen evolution is measured as consequence of short saturating light flashes a pattern is obtained which in agreement with the Kok-Joliot model shows a damped oscillation with a periodicity of four. As usual for most other systems the maximum flash yield is observed under the third flash. In continuous light such slightly greened etioplasts show a small oxygen gush. From our studies it appears that the second 5 min illumination period is obligatory for oxygen evolution. Omission of this period leads to a condition in which under flashes strictly no oxygen is evolved. In continuous light under these conditions no oxygen gush but rather an uptake is observed after onset of illumination. It appears that in greening etioplasts the flash pattern shows some peculiarities when compared to the normal green conditions. Thus, a flash sequence of a greening etioplast always shows a substantial positive amperometric signal under the first flash. The half time of the state which would belong to this signal is 3 to 4 min in a greening etioplast, isolated from leaves that have received 2 h light. In the course of greening this half time decreases continuously and reaches a normal and constant value of approx. 10 s in chloroplasts from green oat or etiochloroplasts that are prepared from leaves that have received 15 h of light. The result is discussed in terms of metastable S3 which seems to be a property of the developing oxygen evolving system in greening oat leaves. In the greening system as we use it is shown for the first time that the photoenzyme protochlorophyllide chlorophyllide reductase is DCMU sensitive.
Properties of Membrane Fractions Prepared by Chromatophore-Liposome Fusion
Authors: Garcia Augusto F. , Drews Gerhart
Published: August 2018

Intracytoplasmic membrane vesicles (chromatophores) isolated from Rhodopseudomonas capsulata cells were fused with liposomes by a pH transition procedure. Vesicles of lower density and higher lipid contents and larger diameter than chromatophores were obtained. Similar results were observed by Ca2+ induced fusion and by the freeze-thawing method. Respiratory and light-induced electron transport were measured in chromatophores and fused vesicles. Light-induced reaction center bleaching was observed in all types of vesicles, whereas repiratory electron transport was substantially diminished by lipid incorporation. Ubiquinone 10 restored to some extent respiratory electron transport and oxidative phosphorylation and it modified the photophosphorylation kinetics under continuous light. Electrochromic carotenoid band-shift and the 9-aminoacridine fluorescence quenching indicate that the capacity of the fused vesicles to maintain an electrochemical proton gradient has not been substantially diminished. From the kinetics of 9-aminoacridine quenching an increased K+-permeability seems to be apparent.
Metabolie Effects of Direct Current Stimulation on Cultured Vascular Smooth Muscle Cells
Authors: Heinle Helmut , Sigg Gerhard , Reich Amo , Thiedemann Klaus-Ulrich
Published: August 2018

Vascular smooth muscle cells from rabbit arteries were grown in tissue culture and stimulated by DC impulses (1 mA, 1V, 10 Hz, 1 ms/imp). Scanning microscopic examination disclosed that in stimulated cultures the cell surface was enlarged by numerous microvilli. This was interpreted as being indicative of an increase in cell activity. Cellular metabolism was character­ized by analyzing the incubation medium for glucose, glutamate/glutamine, and lactate. When compared to unstimulated controls, stimulation caused an increase in the uptake of glucose and glutamine as well as an increased lactate production. The enhancing effect on metabolism was prevented when the “calcium antagonist” verapamil was present (5 × 10-6ᴍ). Although the exact mechanism by which DC stimulation influences the cells remains obscure, this finding indicates an important mediating role of Ca2+ ions.
A High Frequency Mutation Starts Sexual Reproduction in Volvox carteri
Authors: Weisshaar Bernd , Gilles Rainer , Moka Regina , Jaenicke Lothar
Published: August 2018

Pheromone-initiated sexual reproduction of Volvox carteri f. nagariensis is started by a “spontaneous” generation of sexual male spheroids at a rate of 10-4. As previously suggested, these males are mutants (sexc) which become independent of pheromone-controlled sex-induction. Unequivocal evidence for a mutative event now comes from the observation that the sexc trait is transmitted through cell lineages during embryogenesis, thus confirming earlier morphological analysis, Mutation semms to be restricted to cell division, The high frequency of mutation points to a special enchacing mechanism for whick the possibility of a genome rearrangement is discussed.
Arboxeniolide-1, a New, Naturally Occurring Xeniolide Diterpenoid from the Gorgonian Paragorgia arborea of the Crozet Is. (S. Indian Ocean)
Authors: D’Ambrosio Michele , Guerriero Antonio , Pietra Francesco
Published: August 2018

The gorgonian Paragorgia arborea, collected in the Crozet Is. waters at a depth of 280 m during the cruise MD.30/BIOMASS of M/S “Marion Dufresne”, is shown, in what constitutes the first organic-chemical study of a Paragorgiidae, to possess three C20H28O2 xeniolide diter­penoids, two of which are identical with those from a Corallium sp. of the Hawaii. The third xeniolide, arboxeniolide-1, is new as a naturally occurring compound.
Glycoprotein Biosynthesis in Phytophthora megasperma f. sp. glycinea, An in vitro Study / Glycoprotein biosynthesis, race specific determinants, phytophthora megasperma f. sp. glycinea, lipid-intermediates, tunicamycin, diumycin
Authors: Babczinski Peter
Published: August 2018

Extracellular glycoproteins have been claimed to represent the specificity determinants within different races of Phytophthora megasperma f. sp. glycinea (form erly P. m. var. sojae) specifically infective in different soybean cultivars. Microsomal preparations of three different races of Pmg are capable of synthesizing both N-glycosidically linked oligosaccharides and short O-glycosidically linked oligomannoses in vitro from corresponding sugar nucleotides. In addition, lipidic glycosidic intermediates (dolichol type derivatives) serve as specific glycosyl donors. In general, the results demonstrate that the well-known ubiquitous biosynthetic pathway of asparagine-di-Nacetyl- chitobiose type glycoproteins is established in that fungus. The significance of the results regarding specific elicitors, suppressors, protectants, and extracellular glycoenzymes is discussed
Herpetol, a new dimeric lignoid. from herpetospermum caudigerum Wall
Authors: Kaouadji Mourad , Favre-Bonvin Jean
Published: August 2018

The title compound, a new dimer of coniferyl alcohol is the second benzofuran derivative isolated from Herpetospermum caudigerum seeds. Its structure has been elucidated by spectroscopic means as Δ7,7′(E)4,9,9′-trihydroxy- 5,5′-dimethoxy-7.0.4′,8.3′-lignoid
Comparison of the Polypeptide Complement of Different Plastid Types and Mitochondria of Narcissus pseudonarcissus
Authors: Hansmann Paul , Sitte Peter
Published: August 2018

The protein complement of chloroplasts, prochromoplasts, chromoplasts, and mitochondria of the daffodil (Narcissus pseudonarcissus) has been investigated comparatively by gel electrophoresis. Mitochondria do not share common proteins with plastids. On the other hand, there is a broad overlap of the protein complement of the three plastid types investigated, in spite of their different fine structures. There are, however, remarkable differences regarding the relative amounts of many protein species, and certain plastid proteins are entirely absent either from the chloroplasts (e.g., 2 chromoplast proteins in the 60 kDa range) or the chromoplasts (e.g., LHCP). The protein complement of prochromoplasts, which contain chlorophylls and the LHCP, is nevertheless quite more similar to the protein pattern of the chromoplasts than to the one of the chloroplasts.
System Analysis of the Circadian Rhythm of Euglena gracilis, II: Masking Effects and Mutual Interactions of Light and Temperature Responses
Authors: Kreuels T. , Joerres R. , Martin W. , Brinkmann K.
Published: August 2018

Motility of Euglena gracilis shows free running circadian rhythms. The circadian system is sensitive to light and temperature signals, but it is always masked by direct responses of motility to light (photokinesis) and temperature (thermokinesis). By means of a compartimental model which defines the interrelations between the pathways of thermokinesis, photokinesis and the circadian system a unifying view of effects of temperature and light input signals is outlined. According to the model, and using double sine input signals the dynamics of thermokinesis is described by a differential amplifier with constant gain.

Although thermokinesis heavily masks circadian responses to temperature signals, the limited range of circadian entrainment is indirectly demonstrated by a limited reappearance of free running circadian oscillations after stopping the temperature program. Free running circadian oscillations do reappear only after pretreatment with temperature periods near the circadian eigenperiod.

A white mutant lacking photosynthesis is used to investigate the role of photosynthesis in the signal processing. Although light synchronizes the circadian rhythms of the white mutant if applied as single input, it does not affect the motility if applied together with temperature inputs near the circadian eigenperiod. These results indicate frequency dependent mutual interactions between the model compartments.
Inorganic Bromide in Higher Fungi
Authors: Stijve T.
Published: August 2018

A total of 138 samples of higher fungi, representing 35 species (15 belonging to the genus Amanita), were analysed for the trace element bromine using spectrophotometric and gas chromatographic methods. High concentrations of bromine, up to 100 mg/kg on dry weight, were encountered in Amanitaceae, especially in members of the subsections Phalloideae and Eu-Amanita, whereas in other fungi the mean value for this element was only 3,3 m g/kg. Some bromine-accumulating Amanitas also contained unusually high chlorine levels. Am axi­mum concentration of 3 percent on dry weight was measured in A. phalloides. It could be demonstrated that most, if not all of bromine and chlorine was present in the fungi as ionisable inorganic salts. Two organochlorine metabolites, previously reported in some mushrooms, were absent in A. phalloides and A. muscaria.
Phthalide Derivatives from Meum athamanticum Jacq
Authors: Kaouadji Mourad , Mariotte Anne-Marie , Reutenauer Henri
Published: August 2018

A detailed investigation of non polar extracts of Meum athamanticum Jacq. rhizome (Um- belliferae) has led to the isolation of three phthalide derivatives. Sedanenolide, 6.6′,7.3′a-dili- gustilide and ligustilidiol have been identified by their spectral data. Furthermore, occurrence of such compounds seems to suggest assignment of intermediate biogenetic part to (Z)-ligustilide, the most accumulated phthalide in umbelliferous plants.
Alkaloid Sequestration by Papaver somniferum Latex
Authors: Homeyer B. C. , Roberts Margaret F.
Published: August 2018

The 1000 x g organelles of Papaver somniferum latex have been shown to accumulate rapidly, large quantities of alkaloids (0.05- 1 mg/mg organelle protein), particularly morphine, thebaine, codeine and papaverine and have been found to exhibit a surprising degree of specificity for the accumulation of these alkaloids. The uptake of alkaloid is independent of temperature and does not show a requirement for ATP 10-3 ᴍ, Mg2+ 10-3 ᴍ, or KCl 10-3 ᴍ. It is unaffected by known ATPase inhibitors (chlormadinone acetate 2.5 × 10-5 ᴍ, N,N-dicyclohexylcarbo- diimide 5 × 10-4 ᴍ and sodium vanadate 10-4 ᴍ) but showed considerable increase in morphine accumulation in the presence of 4-chloromercumbenzoate 5 x 10-4 ᴍ, while N-methylmaleimide 5 × 10-4 ᴍ had no effect, and carbonylcyanide 4-(trifluoromethoxy)phenylhydrazone 5 × 10-4 ᴍ caused a reduction (ca. 30%) of morphine uptake. An acid medium, pH 4.5-5.5, also results in decreased morphine uptake.
Degradation of the Isoflavone Biochanin A-7-O-glucoside-6"O-inalonate and Phenylacetic Acids by Fusarium javanicum
Authors: Schlieper Dittmar , Komoßa Dieter , Barz Wolfgang
Published: August 2018

Keywords

The isoflavone conjugate biochanin A-7-O-glucoside-6″-O-malonate is degraded by Fusarium javanicum with an esterase to yield biochanin A-7-O-glucoside which is further cleaved by a glucosidase to the aglycone. Biochanin A is funnelled into a known catabolic sequence (Z. Naturforsch. 37c, 861 (1982)). Induction of the catabolism of p-methoxyphenylacetic acid is linked to biochanin A degradation, whereas p-hydroxyphenylacetic acid and 3,4-dihydroxy- phenylacetic acid degradation is substrate-induced.
Cytochromes of the Purple Sulfur Bacterium Ectothiorhodospira shaposhnikovii
Authors: Kusche Werner H. , Trüper Hans G.
Published: August 2018

Two c-type cytochromes (a high spin cytochrome c′ and a low spin cytochrome c-553(549) with asymmetrical α-band) and a low spin cytochrome b-558 from the purple sulfur bacterium Ectothiorhodospira shaposhnikovii were purified by ion exchange chromatography and gel filtration and characterized. Cytochrome c′ has a molecular weight of 33000 (determined by sodium dodecylsulfate electrophoresis), an isoelectric point at pH 4.5 and a redox potential of +37 mV. Absorption spectra show in the oxidized state maxima at 404 nm and in the range of 635 nm, in the reduced form maxima at 426.5 nm, 549 nm and a shoulder at 435 nm. The best purity index obtained was 0.48 (A280/A426.5). Reduced cytochrome c′ reacts with carbon monoxide. Cytochrome c-553(549) has a molecular weight of 10400, an isoelectric point at pH 5.1 and a redox potential of +248 mV. The oxidized form shows the Soret-band at 410 nm. The reduced protein reveals an asymmetrical a-band at 553 nm with a shoulder at 549 nm, the a-band at 522 nm with a shoulder at 528 nm and the γ-band at 416 nm. The best purity index obtained was 0.18 (A280/A416). Roth cytochromes could be isolated from the soluble fraction as well as from Triton X-100 treated membranes. Furthermore very low amounts of cytochromes c-553 and c-552.5 could be detected in detergent treated chromatophores. Cytochrome 6-558 - obtained from cells grown in the presence of reduced sulfur compounds in the medium - seems to be soluble or only weakly bound to the membrane. It has a molecular weight of 15800. an isoelectric point at pH 4.1 and a redox potential of -210 mV. The hemoprotein shows absorption maxima at 424.5 nm. 526.5 nm and 556.5 nm in the reduced form and at 416 nm in the oxidized state. The best purity index obtained was 0.26 (A280/A42,4.5). In addition, there were hints for the occurrence of a high spin cytochrome b′. The cytochrome pattern as well as the amount of cytochromes were dependent on growth conditions.
Influence of the Membrane Potential on the Intracellular Light Induced Ca2+ -Concentration Change of the Limulus Ventral Photoreceptor Monitored by Arsenazo III under Voltage Clamp Conditions
Authors: Ivens I. , Stieve H.
Published: August 2018

The light induced transmission change (Arsenazo signal) of an Arsenazo III injected ventral photoreceptor cell of Limulus polyphemus was studied under voltage clamp. The transmission change which represents a change of free intracellular calcium ion concentration, [Ca2+]i, was investigated for its dependence upon membrane voltage.

The peak amplitude of the Arsenazo signal decreases in a linear fashion with the clamp voltage in the examined voltage range (from -80 to + 40 mV).

In low Ca2+ saline ([Ca2+]e = 250 μᴍ) this decrease in the amplitude of the Arsenazo signal was more pronounced, while in saline with increased Ca2+ ([Ca2+]e = 40, 50 and 100 mᴍ), there is almost no change of the Arsenazo signal with varied membrane voltage.

The recovery of the Arsenazo signal (i.e. recovery of the transmission back to the value before the light flash) is faster during hyperpolarization, this recovery being slowed down when the cell is depolarized.

From these experiments it is concluded that a substantial part of the Arsenazo signal is due to a light induced influx of Ca2+ from the extracellular space across the cell membrane into the cytoplasma. Conceivably the Ca2+ could pass through light activated Na+ channels. Subsequently the increased intracellular Ca2+ is lowered to the preillumination level, by a membrane voltage dependent mechanism possibly an Na+-Ca2+ exchange.

The data do not exclude the possibility that a part of the Ca2+ responsible for the Arsenazo signal is released from intracellular stores.
Untersuchungen an Kalluskulturen von Melissa officinalis L., II Über wasserdampfflüchtige Diterpenkohlenwasserstoffe in nicht differenzierten Oberflächenkulturen / Investigations on Callus Cultures of Melissa officinalis L., II Votile Diterpene Hydrocarbons in Not Differentiated Static Cultures
Authors: Koch-Heitzmann Isabella , Schultze Wulf
Published: August 2018

Dehydroabietane and an other diterpene hydrocarbon, being still unidentified, were found in the steam distillates of callus cultures of Melissa officinalis. The relative proportions of these two diterpenes changed considerably during the course of a cultivation passage. With advancing age of the cells they shifted gradually towards dehydroabietane. Cultures being exposed to conti­nuous light showed the same composition of their steam distillates as cultures which were raised in the dark.
Purification and Properties of Adenosine Kinase from Rat Liver: Separation from Deoxyadenosine Kinase Activity
Authors: Drabikowska Alicja K. , Halec Lidia , Shugar David
Published: August 2018

Ion exchange and affinity chromatography techniques, similar to those previously reported for purification of adenosine kinase from human placenta, were applied to purification of rat liver adenosine kinase. The enzyme, purified 400-fold in 41% yield, was homogeneous on SDS- polyacrylamide gel electrophoresis, with a molecular weight of 52000. It specific activity, 18 μmol/min/mg protein, is the highest hitherto reported for this enzyme from mammalian sources.

Chromatography on DEAE-cellulose removed about 98% of the phosphorylating activity towards 2′-deoxyadenosine present in the initial pH-treated liver extract. The final preparation exhibited only minimal activity (~ 1.5%) under optimal conditions (pH 7.5) vs- 2′-deoxy- adenosine, the lowest yet reported for such a preparation, with a Km of 670 μᴍ, as compared to 0.3 μᴍ for adenosine.

The residual activity towards deoxyadenosine is considered an intrinsic property of the purified adenosine kinase and, in fact, phosphorylation of adenosine was inhibited competitively by deoxyadenosine, with a of 70 μᴍ. Competitive inhibition was also exhibited by cordycepin (3′-deoxyadenosine) with a Ki of 150 μᴍ. A more potent competitive inhibitor was tubercidin, the Ki for which was 1.9 μᴍ.
Production of Four Interfacial Active Rhamnolipids from n-Alkanes or Glycerol by Resting Cells of Pseudomonas species DSM 2874
Authors: Syldatk C. , Lang S. , Matulovic U. , Wagner F.
Published: August 2018

In a simple phosphate buffer or a sodium chloride solution resting cells of Pseudomonas spec. DSM 2874 produced up to 15 g/l of different rhamnolipids. The rhamnolipid composition of the organic crude extract depended on the temperature during the cultivation and on the C-source. The optimal sodium chloride concentration for rhamnolipid formation was about 100 mᴍ/l and the optimal phosphate buffer concentration about 65 mᴍ/l. The optimal pH-value for the production of rhamnolipids from n-alkanes or glycerol was in the range pH 6.0-7.2. While rhamnolipid formation with glycerol as the sole C-source showed a wide optimum ranging from 27° up to 37 °C, production of rhamnolipids from n-alkanes had a sharp optimum at 37 °C. The addition of multivalent cations, different N-sources and EDTA caused an inhibition of rhamnolipid formation, while the n-alkane concentration had no influence. Specific rhamnolipid formation decreased with increasing cell concentration. Various C-sources were suitable for the formation of rhamnolipids by resting cells of Pseudomonas spec. DSM 2874. Yields, which were comparable to those obtained on n-alkanes or glycerol, were found for stearic acid, fatty alcohols and vegetable oils.

A study of the time course of glycolipid production of resting cells was carried out in a 20 1- biorcactor with an intcnsor system and with n-tetradecane as the sole C-source.
Kinetics of Calcium-Induced Fusion of Cell-Size Liposomes with Monolayers in Solutions of Different Osmolarity
Authors: Stoicheva Natalia , Tsoneva Iana , Dimitrov Dimiter S. , Panaiotov Ivan
Published: August 2018

The effects of osmolarity, calcium concentration and cell-size liposomes in the subphase on the surface tension of phospholipid monolayers were investigated. The monolayers were spread from chloroform solutions of phosphatidic acid at air/water solution interface. The liposomes (of average diameter 3 μm) were formed from phosphatidic acid/egg lecithin (1:2) mixtures in water or 0.1 ᴍ water solutions of sucrose.

For this system there were critical concentrations of calcium ions to produce a large reduction of the monolayer surface tension. The threshold calcium concentrations depended upon the sucrose concentration in the subphase. Without sucrose the threshold calcium concentration was 8 mᴍ, while for isoosmotic sucrose solutions (0.1/0.1 ᴍ in/out of liposome) it was 14 mᴍ. It sharply increased to 28 mᴍ CaCl2 at sucrose concentration difference across the liposome membrane 0.02 ᴍ and decreased to 26 mᴍ, 19 mᴍ, and 18 mᴍ with further increase of that difference to 0.04 ᴍ, 0.06 ᴍ, and 0.08 ᴍ, respectively.

The rate of monolayer surface tension decrease was measured as a function of time at 30 mᴍ CaCl2 and different sucrose concentrations in the subphase solution. The initial rates at first decreased with increasing the osmotic pressure and after that they increased. The minimum occurred at sucrose concentration gradient across the liposome membrane 0.02 ᴍ, i.e., at the point of maximum threshold calcium concentration required for large decrease of the monolayer surface tension. These facts may be explained by recent theories of dynamics of adhesion, instability and fusion of membranes modeled as thin films.
In Vitro Cellular Muscle Calcium Metabolism. Characterization of Effects of 1,25-Dihydroxy-Vitamin D3 and 25-Hydroxy-Vitamin D3
Authors: de Boland Ana R. , Boland Ricardo
Published: August 2018

Cultures of vitamin D-deficient chick soleus muscle and 12 day-old chick embryo myoblasts were used to characterize the effects of 1,25-dihydroxy-vitamin D3 and 25-hydroxy-vitamin D3 on muscle cell Ca metabolism. Physiological amounts of both sterols increased the rate and extent of 45Ca uptake by cultures. However. 1.25(OH)2D3 was significantly more effective than 25 OHD3. The greater potency of 1,25(OH)2D3 to increase Ca uptake could be shown after various treatment intervals of cultures and using a wide concentration range of both derivatives. Information about Ca pools affected by vitamin D3 metabolites was obtained through kinetic analysis of Ca efflux in cultured myoblasts. Cytoplasmic and mitochondria Ca pools were identified on the basis of their half-times of desaturation and by selective inhibition of plasma membrane and mitochondrial Ca transport with LaCl3 and Ruthenium Red, respectively. The data suggests that 1,25(OH)2D3 acts on muscle cellular Ca by increasing Ca efflux and influx through mitochondrial and plasma membranes whereas the predominant effect of 25 OHD3 is to increase Ca influx into mitochondria.
Effect of Light Intensity on Photosynthetic 14C O2 Fixation of Anabaena flos-aquae
Authors: Döhler Günter , Märte Alfred
Published: August 2018

The cyanobacterium Anabaena flos-aquae (strain 1444) grown at different intensities of white light (900, 3500 and 30000 lux) showed changes in the content and composition of the pigments. Phycocyanin was more affected by high light conditions during growth than chlorophyll a. In comparison to in low white light grown cyanobacteria number of phycobilisomes and thylakoids decreased under strong light. A diminution of 14CO2 fixation, total amino acid content, glutamic acid and glutamine pools was found in strong white light grown cells. Under these conditions the majority of 14C-labelling was measured in sugar phosphates. After pressure treatment a marked increase of 14C-incorporation into amino acids could be obtained. Results were discussed with reference to regulation of buoyancy in Anabaena flos-aquae.
Male Produced Volatiles from Coreid Bug Leptoglossus australis\ (Heteroptera)
Authors: Gough A. J. E. , Games D. E. , Staddon B. W.
Published: August 2018

From the ventral abdominal gland VII-VIII in male adult Leptoglossus australis, five volatiles have been identified by GC and MS data in comparison with authentic standard materials. Benzyl alcohol (31%) and 2-phenyl ethanol (42%) together accounted for over 70% of the total scent. The remaining materials identified were 2-octenyl propionate (19%), (E,E′)-2,4-hexadienyl acetate (6%) and (E)-2-hexenol (2%).
Studies on the Triple Helical Structure of β-ᴅ-1,3 Xylan
Authors: Haleem M. A. , Qamruddin Salma
Published: August 2018

The triple helical structure of β-ᴅ-1,3 xylan is described. The 0-value is reduced to 3.447 from 4.417 by number of small modifications to the structure including variations in the position of water molecule. The R-value after the refinement is found to be 0.37. The present calculations indicate that water is certainly involved with the structure possibly in a more complicated way as proposed by earlier workers. The present work supports the previous finding of Haleem and Parker that the molecule should be 8% smaller in radius.
The Role of N ADPH in the Reversible Phototransformation of Chlorophyllide P682 into Chlorophyllide P678 in Etioplasts of Oat
Authors: Franck Fabrice , Schmid Georg H.
Published: August 2018

Absorption spectra and room temperature fluorescence variations upon light excitation were studied in etioplasts in which the protochlorophyllide had been reduced to chlorophyllide prior to the experiment. In the presence of 1 mᴍ NADPH, the absorption band was located around 682 nm and the fluorescence variations reflected the occurrence of the chlorophyllide microcycle (reversible phototransformation of chlorophyllide P682 into chlorophyllide P678), whereas, in the absence of NADPH, the absorption band was located around 676 nm and the fluorescence exhibited only a slow decrease with illumination time. After washing, NADPH-treated etioplasts still exhibited an absorption maximum of 682 nm, which shifted irreversibly to 678 nm upon illumination. Re-addition of only 10 μᴍ NADPH restored the reversibility of the reaction. Plastids were also prepared after a brief illumination of the intact leaves. These plastids contained the P682 chlorophyllide. In this preparation, essentially the same phenomena were observed as in NADPH-treated etioplasts after washing. Moreover, enzymic oxidation of NADPH resulted in the transformation of P682 into P678 in darkness. Addition of the Hill electron acceptors 2,6- dimethylbenzoquinone on FeCN caused an acceleration of the phototransformation of P682 into P678. We interpret these results as being due to the oxidation of NADPH during the phototransformation of P682 into P678. The nature of the electron acceptor and the physiological role of this reaction is discussed.
Reculturing of Cells from Primary CFU-C Colonies
Authors: Hübner G. E. , Ali-Osman F. , Kästner M. , Papadimitriou C. , Maurer H. R.
Published: August 2018

This study was aimed at investigating whether cells of CFU-C derived colonies could form secondary colonies. Bone marrow cultures of volumes of agar medium between 25 μl and 75 μl contained in glass capillaries were stimulated with mouse lung-conditioned medium (MLCM) containing granulocyte/macrophage colony-stimulating factor (GM-CSF). Agar gels with colonies of up to ≥ 20 were blown out into identical culture medium, completely dispersed on a whirl-mix to single cell suspensions, and used for establishing secondary agar cultures. In these secondary cultures considerable numbers of secondary granulocytic, mixed granulocytic/macrophage and macrophage colonies as well as numerous clusters arose. In contrast, when single colonies were recultured, only few secondary cell aggregates were formed. When primary cultures containing up to ≥ 20 cell aggregates were used for serial reculture at intermittent intervals of 3 and 4 days, a 2 -7-fold increase of colony-forming cells was found in tertiary cultures as was monitored by 7 day colony counts. And by use of different kinds of CSF-containing media, an over 4-fold increase of secondary over primary colonies was obtained with bovine lung-conditioned medium (BLCM) in primary and L-cell-conditioned medium (LCCM) in secondary 7 day cultures. Primary capillary cultures were found to be devoid of CFU-S. Also, setting up bone marrow cultures in petri dishes and stimulating with MLCM, growth of primary as well as secondary colonies was obtained. The results indicate some self-renewal potential of CFU-C in vitro.
Säugetierspermatogenese als biologischer Indikator für ionisierende Strahlung / Mammalian Spermatogenesis as a Biological Indicator for Ionizing Radiation
Authors: Hacker-Klom Ursula , Meier Eva-Maria , Göhde Wolfgang
Published: August 2018

We have analysed spermatogenetic cells by flow cytometry to quantify effects of ionizing radiation. The radiation-induced reductions of testicular DNA-synthesizing cells, primary spermatocytes, haploid round and elongated spermatids as well as the increases of numerical chromo­ some aberrations (abnormal diploid spermatids and aneuploidies) in NMRI inbred mice are described. Testicular weights were determined as a parameter of germ cell decrease, and histologic cross sections of the testes were analysed. Since even an exposure of 0.05 Gy (= 5 rad) may be detected by a reduction of DNA-synthesizing cells (Acta Radiol. Oncol. Radiat. Phys. Biol. 21, 349-351 (1982) [1]), the use of the in vivo system “spermatogenesis” as a biological dosimeter to monitor low dose effects and to determine RBE values of different radiation qual­ ities is suggested.
Analytical Ultracentrifugation of Proteins in Solutions of Triton X-100 Using Absorption Optics
Authors: Schubert Dieter , Boss Karin
Published: August 2018

Analytical ultracentrifugation studies on proteins in solutions of the nonionic detergent Triton X-100, by means of a UV scanning system, can be conveniently performed by the following procedure: (1) Scanning of the cells is done at a wavelength of 246 nm. (2) The sedimentation of the deter­ gent is prevented by appropriate adjustment of the solvent density. (3) The reference cell is filled with water. Reliable molecular weight determinations can be performed at detergent concentrations up to 0.4% (w/w) in cells of path-length d = 12 mm and at correspondingly higher concentrations for d - 3 mm. Approx. 10 μg of protein are sufficient for a determination. The method should be useful for studies of membrane proteins.
ʟ-Tyrosine as a Precursor of Flavonoids in Buckwheat Cotyledons
Authors: Margna U. , Laanest L. , Margna E. , Vainjärv T.
Published: August 2018

Exogenous ʟ-tyrosine was incorporated 13 -14 times less effectively than exogenous L-phenylalanine into flavonoids in excised cotyledons of 3 days old buckwheat seedlings but proved to be an only 5 times poorer precursor when the experiments were carried out with 5 days old material. Simultaneous administration of ʟ-phenylalanine markedly reduced incorporation of ʟ-tyrosine into flavonoids. A similar decrease in the utilization of exogenous ʟ-tyrosine for flavonoid bio­ synthesis occurred in kinetin-treated cotyledons. However, in cotyledons treated with high doses of glyphosate, an inhibitor of the shikimic acid pathway, an increase in the formation of flavonoids from exogenously supplied ʟ-tyrosine was observed. Under all conditions the relative incorporation rate of exogenous L-tyrosine was highest for anthocyanins and lowest for C-glycosylflavones while within the latter class of compounds the luteolinic derivatives orientin and isoorientin incorporated more label than their apigeninic analogues vitexin and isovitexin. PAL and TAL activities were found to be present in the cotyledons in a ratio of 50:1. The possible role of ʟ-tyrosine as an alternative natural precursor for the biosynthesis of flavonoids and other related polyphenols is discussed.
Two Different Chalcone Synthase Activities from Spinach
Authors: Beerhues L. , Wiermann R.
Published: August 2018

Chalcone synthase activity was found in enzyme preparations from spinach. In homogenates of young leaves two different activities of the enzyme could be separated by DEAE-ion exchange chromatography and chromatofocusing. Both activities formed naringenin with [2-14C] malonyl- CoA and 4-coumaroyl-CoA as substrates. They exhibited only slight differences in substrate specificity. For both activities 4-coumaroyl-CoA proved to be the most suitable substrate at both pH 6.8 and 8.0. Eriodictyol and homoeriodictyol formation from caffeoyl-CoA and feruloyl-CoA, respectively, only occured at pH 6.8. The formation of naringenin by the two activities was maximal at pH 7.5-8.0 and dependent upon the DTE-concentration in the assay mixture.
Isolation of Vacuoles from the Upper Epidermis of Petunia Hybrida Petals. I. A Comparison of Isolation Procedures
Authors: Aerts J. M. F. G. , Schram A. W.
Published: August 2018

Vacuoles were isolated from the upper epidermis of petals of Petunia hybrida line R27 using three different procedures. Utilizing the vacuolar localization of anthocyanin, vacuolar prep­arations obtained through polybase treatment, osmotic shock and mechanical forces were com­pared on purity, yield and stability. The comparison indicated that application of the polybase procedure results in the best vacuolar preparations. Vacuoles could be obtained which main­tained their acidic pH and retained their anthocyanin content.