bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incorporation of Radiolabeled Tyrosine, N-Acetyldopamine, N-β-Alanyldopamine, and the Arylphorin Manducin into the Sclerotized Cuticle of Tobacco Hornworm (Manduca sexta) Pupae
Authors: Grün Lothar , Peter Martin G. 
Published: August 2018

Abstract
Radiolabeled manducin, which is the arylphorin (i.e. tyrosine-rich larval serum protein) of the tobacco hornworm Manduca sexta was prepared by in vivo biosynthesis from [U-14C]-ʟ-tyrosine. In order to see whether manducin is incorporated into the cuticle of developing pupae and participates in cuticle sclerotization, the radiolabeled protein was injected into late last larval instar larvae. Fractionation of the sclerotized pupal cuticle into a buffer soluble, acid soluble and acid insoluble fraction shows that up to 2.6% of peptidic tyrosine residues end up in the acid soluble portion. Another 0.5% are recovered from the acid insoluble fraction by combustion. Only 30% of peptidic tyrosine residues of manducin incorporated into the acid soluble fraction are recovered as tyrosine. The presence of radioactivity in the acid insoluble fraction suggests that peptidic tyrosine residues are transformed partly into melanin-like material. The in­corporation of manducin into the cuticle of pupae is also evident from immunological studies.
Relative large quantities of radiolabeled acid insoluble melanine like material is also recovered from sclerotized cuticle after incorporation of radiolabeled tyrosine as well as tanning substrates N-acetyldopamine and N-β-alanyldopamine. Application of doubly labeled [7-3H,8-14C]-N-acetyldopamine shows a high loss of 3H in the acid insoluble fraction. It is suggested that tanning agents form lignine-like polymers and that sclerotization results from copolymerization with peptidic tyrosine residues in the cuticle. Thus, the arylphorin manducin appears to be an important constituent of the sclerotization system in Manduca sexta.
Juvenile Hormone III as a Natural Ligand for Photoaffinity Labelling of JH-Binding Proteins
Authors: Stupp Hans-Peter , Peter Martin G. 
Published: August 2018

Abstract
Juvenile hormone III, i.e. methyl 10,11-epoxy-3,7-dimethyl-2E,6E-dodecadienoate, was used for photoaffinity labelling of JH-binding proteins. Irradiation of haemolymph from Manduca sexta and Locusta migratoria in the presence of racemic [10-3H]JH-III results in covalent incorporation of up to 3.2% of the radioactivity into an acetone insoluble protein fraction. Resolution of the proteins by HPLC and by SDS-PAGE confirms the presence of radiolabelled JH-binding proteins. Proteins not involved in JH-binding in insect haemolymph are labelled photochemically with lower yields only. Thus, JH-III is a suitable natural ligand for photoaffinity labelling of high-affinity binding sites. Use of the natural hormone instead of a hormone analog bears the major advantage that the binding with a JH-binding protein will occur at specific sites.
Hormone Induced Changes in Carotenoid Composition in Ricinus Cell Cultures. II. Accumulation of Rhodoxanthin during Auxin-Controlled Chromoplast Differentiation
Authors: Gemmrich Armin R. , Kayser Hartmut 
Published: August 2018

Abstract
The effects of auxin and cytokinin on light dependent carotenoid synthesis were studied in callus cultures derived from Ricinus endosperm tissue. Chloroplasts differentiate when calli are grown in the light in the presence of cytokinin and auxin. When cultures are transferred to an auxin-free medium, chromoplast differentiation is initiated, i.e. rhodoxanthin accumulates whereas lutein and chlorophyll content decrease and the plastid morphology changes from that of a typical chloroplast to that of a globular-type chromoplast. These changes are fully reverted by readdition of auxin. Plastid differentiation into either chloroplasts or chromoplasts in Ricinus endosperm cultures therefore appears to be controlled by auxin and cytokinin.
Notizen: Specificity of Synthetic Sex-Attractants in Zygaena Moths
Authors: Priesner Ernst , Naumann Clas M. , Stertenbrink Johannes 
Published: August 2018

Abstract
Species-specific sex-attractants are reported for western Palearctic Zygaena moths of the carniolica, viciae, filipendulae, and purpuralis species groups. The attractants were established by combined electrophysiological and field behavioural studies and consist of ternary combinations of (Z)-7-dodecenyl/(Z)-9-tetradecenyl acetates with a particular further (Z)-alkenyl acetate. Data on other Zygaenini taxa are included.
Characterization of Microcystis Strains by Alkyl Sulfides and β-Cyclocitral
Authors: Jiittner Friedrich 
Published: August 2018

Abstract
Cyanobacteria of the genus Microcystis have been found to liberate large amounts of β-cyclo- citral. While all seven strains of Microcystis studied possessed this property, it has not been found in any other cyanobacterial species. This chemical characteristic of the genus Microcystis enables the unequivocal systematic arrangement of controversial species. Another chemical property allows two chemotypes to be distinguished within the genus Microcystis: one exhibits an intensive release of isopropylmethyl disulfide, diisopropyl disulfide and diisopropyl trisulfide, substances which have not been previously found in any microorganism. The second chemotype excretes dimethyl disulfide and in some cases also dimethyl trisulfide and dimethyl tetrasulfide. Species producing isopropyl sulfides emanate an intensive sulphurous malodour.
Development-Specific Incorporation of [14C]5-Aminolevulinate and [3H]Leucine into Cytochrome c and Biliprotein in the Butterfly, Pieris brassicae. Correlation with the Ecdysteroid Titer in the Pupa
Authors: Kayser Hartmut , Krull-Savage Ute 
Published: August 2018

Abstract
Incorporation of [14C]5-aminolevulinate and [3H]leucine into cytochrome c, biliprotein and total soluble protein was followed from the last larval instar to the adult stage in Pieris brassicae. The titer of ecdysteroids during the pupal stage was determined with a radioimmunoassay to correlate synthesis of heme products and of protein(s) with adult differentiation. Incorporation of both precursors showed a developmental profile with high synthetic activities in feeding larvae and in pupae after the release of ecdysteroids. Variation of the hormone titer during pupal life differed significantly in males and females. Labeling of cytochrome c by both 14C and 3H was as expected from the variation of its concentration reported in a preceding paper; highest in corporation was around adult emergence. The results demonstrate that i) the accumulation of cytochrome c in the developing adult insect is primarily due to de novo synthesis of both heme and apocytochrome c, performed under coordinate control, and ii) the concentration of 5-aminolevulinate is not rate-limiting in the formation of cytochrome c. Biliverdin IXγ, the major tetrapyrrolic product in this insect, seems to be directly derived from (free) heme and relatively short-lived as deduced from a time-course study. Formation of the bilin, i.e. destruction of heme, increased concomitantly to the initiation of adult differentiation by ecdysteroids in the pupa but later decreased at adult emergence. Synthesis of cytochrome c takes place as a late event during terminal development. Thus, the pathways leading to the two major heme products seem to be differently regulated during development.
Chemical and Physical Characterization of Four Interfacial-Active Rhamnolipids from Pseudomonas spec. DSM 2874 Grown on n-Alkanes
Authors: Syldatk Christoph , Lang Siegmund , Wagner Fritz , Wray Victor , Witte Ludger 
Published: August 2018

Four extracellular glycolipids produced under growth-limiting conditions were isolated from the culture broth of Pseudomonas spec. DSM 2874. After purification by column and thick-layer chromatography they were identified as anionic rhamnolipids. 1H and 13C-NMR studies showed that two of these, β(β(2-O-α-ʟ-rhamnopyranosyloxy)decanoyl)decanoic acid and β(β(2-O-α-ʟ- rhamnopyranosyl-α-ʟ-rhamnopyranosyloxy)decanoyloxy)decanoic acid, were identical with com­pounds described previously, while the other more hydrophilic compounds, β(2-O-α-ʟ-rhamno- pyranosyloxy)decanoic acid and β(2-O-β-ʟ-rhamnopyranosyl-a-ʟ-rhamnopyranosyloxy)decanoic acid, were new compounds.
Surface and interfacial activity of the organic crude extract and of the purified components were determined in different aqueous solutions. The pH-dependence of surface and interfacial properties of the two previously described rhamnolipids (4. 20. 23) were examined in Teorell- Stenhagen-buffer (supplemented with 10% NaCl) at pH 3.0 and pH 9.0. All rhamnolipids reduced the surface-tension from 72 to about 30 mɴ/m and the interfacial-tension from 42 to about 1 mɴ/m. The critical micelle concentrations were of the order of 5 to 200 mg/l depending on the structure of the molecule.
Enzymatic Nitrate Assay by a Kinetic Method Employing Escherichia coli Nitrate Reductase
Authors: Schild Johannes , Klemme Jobst-Heinrich 
Published: August 2018

Abstract
An enzymatic assay system for nitrate employing the membrane-bound nitrate reductase (EC 1.7.99.4) of E. coli is described. Contrary to previous enzymatic assay systems, the present method is a kinetic one, i.e. the substrate, nitrate, is assayed by measuring the reaction rate of the nitrate reductase-catalyzed reaction. Based on the observation that the nitrate reductase-catalyzed reaction obeys pseudo-first order kinetics, a test system is described allowing the assay of nitrate at a concentration as low as 1 ppm. The relatively high M ichaelis-M enten constant for nitrate (0.3 mᴍ) of the E. coli nitrate reductase favours nitrate assay by the kinetic method.
Antiserum Against the 33-kDa Herbicide-Binding Protein
Authors: Herrmann Gerhard , Thiel Andreas , Böger Peter 
Published: August 2018

Abstract
A rabbit antiserum was prepared against the purified 33-kDa herbicide-binding protein (HBP) from the alga Bumilleriopsis filiformis. Specificity at 1:10,000 dilution (v/v) of the unpurified serum is detectable in the immunoblotting assay with both the 33-kDa protein from the alga Bumilleriopsis as well as that from Spinacia. Agglutination can be observed with photosystem-II particles only, not with intact thylakoids, indicative of a hidden location of the protein determinants in the membrane. Neither herbicide binding nor electron transport is influenced by the antibody. Apparently, the antigenic site of the HBP for the antibody used here is different from the herbicide-binding region.
A Patch Clamp Study of Tonoplast Electrical Properties in Vacuoles Isolated from Chenopodium rubrum Suspension Cells
Authors: Bentrup Friedrich-Wilhelm , Hoffmann Bernd , Gogarten-Boekels Maria , Gogarten Johann Peter , Baumann Christian 
Published: August 2018

Abstract
The patch clamp technique has been applied to isolated vacuoles from green suspension cells of Chenopodium rubrum to record electrical parameters of the tonoplast. In a symmetrical K+ solution of 46 mᴍ, the membrane displays a near zero voltage, whereas 2 mᴍ ATP will hyper-polarize it to 15 or 20 mV (vacuole positive). The conductance amounts to about one S · m-2. Fluctuations of the clamp current are explained by an unknown channel species having opening times of 5 - 10 ms. Together with previous work on a tonoplast vesicle preparation and unpublished data on vacuoles from our laboratory, the present results indicate an electrogenic membrane ATPase pumping protons from the cytoplasm to the vacuole.
Calcium, Iron and Cobalt Accumulation in Root Hairs of Soybean (Glycine max)
Authors: Werner Dietrich , Kuhlmann Klaus-Peter , Gloystein Frank , Richter Friedrich-W. 
Published: August 2018

Abstract
Root hairs of soybeans (Glycine max), target cells for infection by Rhizobium japonicum accumulate iron more than 10-fold, cobalt more than 8-fold and calcium more than 7-fold compared to the other parts of the root system. In root hairs of wheat (Triticum aestivum) a much smaller accumulation of these elements was found. The symbiont of Glycine max, Rhizobium japonicum, is known to have a high requirement for iron, cobalt and calcium.
Growth Response of Mouse Lymphoma Cells to Low Concentrations of Mercuric Chloride
Authors: Jost Stephan Paul , Cole Jane , Goodwin Brian C. 
Published: August 2018

Abstract
Three growth rate experiments involving several sampling points were performed to investigate the previous finding that very low concentrations of HgCl2 inhibit the growth of murine lymphoblasts in vitro. However, results presented here do not confirm this, there being no significant differences between the three independent growth rate experiments.
Small-Angle X-Ray and Light Scattering Studies on the Influence of Mg2+ Ions on the Structure of the RNA from Bacteriophage MS 2
Authors: Ribitsch Gertraud , Clercq Rita De , Folkhard Waltraud , Zipper Peter , Schurz Josef , Clauwaert Julius 
Published: August 2018

The influence of Mg2+ ions on the secondary and tertiary structure of the RNA from bacteriophage MS2 was investigated by small-angle X-ray scattering and light scattering and by sedimentation experiments.
The analysis of the outer part of the X-ray scattering curve obtained at low temperature in the absence of Mg2+ yielded a cross-section radius of gyration of 0.88 nm and a mass per unit length of 1720 g mol-1 nm-1. Very similar values for these parameters, which refer to the secondary structure of the RNA molecule, were also derived from the X-ray scattering curves obtained in the presence of different amounts of Mg2+ (0.07 to 1 ions per nucleotide). On the contrary, the inner part of the X-ray scattering curves turned out to be highly dependent on the Mg2+ concen­tration: the cross-section radius of gyration and the mass per unit length, which were determined from the scattering curves at small angles as parameters related to the tertiary structure of the RNA, amounted to 3.11 nm and 4000 g mol-1 nm-1, respectively, in the absence of Mg2+ and in­creased significantly upon raising the concentration of Mg2+. The increase of these structural parameters was found to be accompanied by a decrease of the overall radius of gyration (as revealed indirectly by X-ray scattering and directly by light scattering measurements) and by an increase of the sedimentation coefficient.
The results from the investigations of the RNA at low temperature clearly establish the existence of double-stranded structures down to very low Mg2+ concentrations as well as the occurrence of Mg2+ induced changes of the tertiary structure. In the absence of Mg2+ the RNA molecule appears to be a rodlike particle of about 300 nm length with a lateral diameter of about 9 to 11 nm. Upon addition of increasing amounts of Mg2+ this extended structure tightens, eventually forming a coil-like particle. Previous X-ray scattering experiments with MS2 RNA at ionic strength 0.1 (Zipper, Folkhard and Clauwaert, FEBS Lett. 56, 283-287 (1975)) have already established the axial dimensions of such coil-like particles to be about 63, 31 and 14 nm.
The results from supplementary X-ray scattering experiments performed at higher temperatures in the absence or presence of Mg2+ clearly reflect the loss of secondary structure due to melting of the RNA. This loss is, however, less pronounced at higher concentrations of Mg2+ .
Properties of Lectins from Snails of the Genus Helix Probed by Monoclonal Antibodies
Authors: Schneider Hansjörg A. W. 
Published: August 2018

Abstract
Helix-Lectins, Monoclonal Antibodies against Lectins, C om petition between Antibodies and Carbohydrates Monoclonal antibodies were raised against the lectin of H elix pom atia (HPL). Besides anti­ bodies bearing the more common y and x chains, antibodies with a, /j. and X2 chains were elicited. The anti-HPL antibodies are expected to be useful in studies on HPL biogenesis and HPL sub­ structure and in studies concerned with the binding of HPL to cell surfaces. Binding of carbohydrates to HPL im paired the binding of anti-H PL antibodies. One to 3 m M GalNAc inhibited HPL-binding in two out of nine antibodies. None of the antibodies bound in the presence of micrograms per ml of the polyvalent blood group A-substance from hog stomach. Similarly, all anti-HPL antibodies were prevented from binding if non-inhibitory concentrations of A-substance were supplem ented with GalNAc. Lectins from H elix aspersa (HAL) and H elix lucorum (H LL) differed from HPL in antigenic properties. Only one anti-HPL antibody each bound these lectins as well as HPL. Binding of lectins of Cepaea and Rapana was scarcely detectable. Most of the anti-HPL antibodies and the m ultivalent H PL-antigens formed precipitation lines in double diffusion tests. At least two antibodies (IgMs) did so with HLL but none with HAL. The possibility that antibodies were selected because of unknown interactions between HPL and the carbohydrate moieties of certain fractions of antibodies was excluded by raising the antibodies in the presence of tunicamycin to inhibit N-glycosylation.
Untersuchungen zur Sterinsynthese des Ascomyceten Aureobasidium (Dematium) pullulans / Studies of the Sterolsynthesis in the Fungus Aureobasidium (Dematium) pullulans
Authors: Flesch Peter , Schaefer Michael 
Published: August 2018

Abstract
Isolation and identification of sterols from culture extracts of the fungus Aureobasidium (Dematium) pullulans yielded metabolites with key function in sterol synthesis. By proof of squalene, lanosterol/dihydrolanosterol, desmosterol, ergosterol, cholesterol, stigmasterol and β-sitosterol it was possible to work out a general synthesis-scheme for the building-up of sundry sterols in Ascomycetes.
Fluorescence-ODMR of Light Harvesting Pigments of Photosynthetic Bacteria
Authors: Angerhofer A. , Schütz J. U. von , Wolf H. C. 
Published: August 2018

Abstract
Fluorescence detected ODMR measurements in zero field on the triplet states of light harvest­ing (LH) pigments in chromatophores from Rhodopseudomonas sphaeroides R 26.1 and Rhodo­pseudom onas capsulata A1a+ are reported. In both cases at least two distinct triplet states in the antenna system with zfs values of D between 209 and 217 and E between 56 and 67 x 10-4 cm-1 are observed.
Isomerase and Decarboxylase Activities in the 4-Hydroxyphenylacetate Catabolic Pathway of Pseudomonas putida
Authors: Martín M. L. , Garrido-Pertierra A. 
Published: August 2018

Abstract
5-Carboxymethyl-2-hydroxymuconate isomerase and 5-carboxymethyl-2-oxo-hex-3-ene-1,6-dioate decarboxylase in the 4-hydroxyphenylacetate meta-cleavage pathway have been purified to over 98% homogeneity. The native enzymes, which appear to be monomers, have apparent molecular weights of 37,000. The isomerase shows a pH optimum 8.0 and does not require ions for its catalytic activity; Mg2+ is required for the decarboxylase reaction. Apparent Km values for their respective substrates are 2.8 × 10-4м for the isomerase and 1.4 × 10-4м for the decarboxy­ lase. The highly purified enzymes were used to study the spectral characteristics of the decarboxy­ lase substrate.
Invariance of Stoichiometry of the Sarcoplasmic Reticulum Calcium Pump at Physiological Calcium Concentrations – a Reevaluation
Authors: Hasselbach Wilhelm , Migala Andrea 
Published: August 2018

Abstract
The decline of the transport ratio of the sarcoplasmic calcium pump observed in a recent study (A. results from the retardation of calcium oxalate precipitation at low calcium/protein ratios. The prevailing high internal calcium level supports a rapid calcium backflux and a compensatory ATP hydrolysis during net calcium uptake which reduces the transport ratio. Yet, the determined calcium back­ flux does not fully account for the decline of the transport ratio. A supposed modulation of the stoichiometry of the pump by external calcium (0.1 μм) is at variance with results of previous studies showing a constant transport ratio of two in the same calcium concentration range.
On the Active Principles of the Spurge Family (Euphorbiaceae) XI. [1] The Skin Irritant and Tumor Promoting Diterpene Esters of Euphorbia tirucalli L. Originating from South Africa
Authors: Fürstenberger G. , Hecker E. 
Published: August 2018

Abstract
The irritant and tumor-promoting constituents of latex of Euphorbia urucalli L. originating from South Africa were isolated. They were identified as irritant ingenane and tiglianc type diterpene esters derived from unsaturated aliphatic acids and acetic acid and the polyfunctional diterpene parent alcohols 4-deoxyphorbol, phorbol and ingenol, respectively.
The irritant and tumor-promoting esters of 4-deoxyphorbol are predominant and were fully characterized chemically and biologically. They are positionally isomeric 12,13-acylates, acetates e.g. Euphorbiafactors Ti1 -Ti4. As acyl groups they carry homologous, highly unsaturated aliphatic acids of the general structure CH3-(CH2)m-(CH = CH)n-COOH (m = 2,4; n =1,2,3,4,5; N = 2n + m + 2). Corresponding diesters of 4-deoxy-4α-phorbol are also present which are biologically inactive. Comparison of structures and biological activities of 12,13-diesters of 4-deoxyphorbol indicates that - for a distinct total number of C-atoms (N) in the acyl moiety - an increasing number of conjugated double bonds In} may increase the irritant but decrease the tumor-promoting activity. Replacement of the hydroxyl function at C-4 (phorbol-12,13-diesters) by hydrogen (corresponding 4-deoxyphorbol-12,13-diesters) does not essentially alter biological activities. Epimerization of 4-deoxyphorbol-12,13-diesters at C-4 abolishes biological activities.
The specific chemical properties demonstrated for the diterpene ester irritants contained in the latex of E. tirucalli and hence in all plant parts may be useful in trials to abolish the potential risk of cancer involved especially in occupational mass production and handling of the plant. Some of the structure activity relations of the Euphorbia factors isolated made them excellent tools in experimental cancer research for the analysis of mechanisms of tumorigenesis.
(Z)-9-Dodecenyl Acetate, a Component of the Sex Pheromone of Cnephasia longana Haworth (Lepidoptera: Tortricidae)
Authors: Bestmann Hans-Jürgen , Attygalle Athula , Platz Hans , Vostrowsky Otto , Glas Michael 
Published: August 2018

Abstract
By means of electrophysiological investigations, GC- and GCMS-analysis of gland extracts and GC-analysis with EAG-detection (Z)-9-dodecenyl acetate was proven to be a component of the sex pheromone of female Cnephasia longana moths. (E)-9-dodecenyl acetate acts as a pheromone inhibitor, as shown by field trials.
Separation of Chloroplast Thylakoid Membrane Polypeptides by Electrophoresis on Polyacrylamide Gradient Gels with a Length of 60 cm
Authors: Schmidt H. Oskar , Süss Karl-Heinz 
Published: August 2018

Abstract

14C labeled thylakoid membranes of Vicia faba chloroplasts were separated by one-dimensional electrophoresis in gel cuvettes of different length using a 12 - 18% polyacrylamide gradient gel system containing 0.1% sodiumodecylsulfate and 6 ᴍ urea. The use of gels with a length of 22 cm and 60 cm led to the detection of about 40 and 80 polypeptide bands, respectively, after dye staining and 50 and more than 100 polypeptide bands, respectively, after autoradiography. The conditions used strongly denaturate chlorophyll proteins and avoid the formation of different polypeptide conformations. Polypeptides differing in molecular mass from about 3000 to 70000 were separated in sharp bands.