bluuebunny/crossref_metadata_2025 huggingface dataset:
Photophosphorylation by Chloroplasts: Effects of Low Concentrations of Ammonia and Methylamine
Authors: Giersch Christoph
Published: August 2018

Intact chloroplasts exposed to hypotonic assay conditions are capable of photophosphorylating exogenous ADP. The rate of phosphorylation by these unbroken plastids is increased by 10-50% upon the addition of low concentrations (<mм) of NH3 or CH3NH2. Stimulation of phosphorylation is abolished by washing chloroplasts with MgCl2. Evidence is presented that washing removes a factor responsible for amine-induced increase of ATP production and that this factor is associated with the thylakoid membrane. Addition of CH3NH2 increased the proton permeability of the thylakoid membrane of unbroken and washed chloroplasts during the light/dark transition. Hence, differences of the membrane permeability for protons between the two preparations seem not to be responsible for an increase of ATP production upon the addition of amines. Stimulation of photophosphorylation by methylamine is observed even at light itensities which do not saturate the proton motive force, which in turn is reduced upon the addition of the uncoupler. Apparently, phosphorylation can be stimulated, although the limiting driving force is diminished. It is concluded that phosphorylation by unbroken chloroplasts under low light illumination is limited kinetically, not energetically. Consequences of these findings for observation made with intact chloroplasts are discussed.
Herbicides which Inhibit Electron Transport or Produce Chlorosis and Their Effect on Chloroplast Development in Radish Seedlings I. Chlorophyll a Fluorescence Transients and Photosystem II Activity
Authors: Grumbach K. H.
Published: August 2018

Diuron and bentazon are very strong inhibitors of the photosynthetic electron transport in isolated radish chloroplasts. The chlorosis producing herbicide SAN 6706 also inhibited the photosystem II dependent oxygen evolution. Aminotriazole had no effect. The inhibitor concentration for 50% inhibition of photosystem II activity was 10-7 m for diuron and 10-4 m for bentazon and SAN 6706 respectively.

Diuron and bentazon quenched the chlorophyll a fluorescence transients in isolated radish chloroplasts drastically, while aminotriazole was not effective. It was of particular interest that the bleaching herbicide SAN 6706 inhibited photosystem II dependent oxygen evolution in a similar concentration as bentazon but had no effect on the chlorophyll a-fluorescence transients suggesting that SAN 6706 is not binding to the same site of the electron transport chain as diuron and bentazon.

Apart from their direct influence on electron transport in isolated photosynthetically active chloroplasts the photosystem II and bleaching herbicides assayed also strongly affected photosynthesis in radish seedlings that were grown in the presence of the herbicides for a long time. As already obtained using isolated chloroplasts, photosystem II dependent oxygen evolution like the chlorophyll a fluorescence transients were strongly inhibited by the photosystem II herbicides diuron and bentazon. A reduction but no inhibition of photosystem II activity was observed in plants that were grown in the presence of aminotriazole. The pyridazinone SAN 6706 was behaving contradictory. In partly green plants photosystem II activity was still maintained and even higher than in untreated plants while in albinistic plants no photosynthetic activity was detected.
Subcellular Fractionation of Bone Marrow-Derived Macrophages: Localization of Phospholipase A1 and A2 and Acyl-CoA:1-Acylglycero-3-phosphorylcholine-0-acyltransferase
Authors: Krüner Ellen E. , Fischer Herbert , Ferber Ernst
Published: August 2018

Phospholipase A1 and A2, Lysolecithin-Acyltransferase, Macrophage, Subcellular Localization Analysis of the subcellular distribution of lipid-metabolizing enzymes was carried out in bone marrow-derived macrophages with special respect to a comparison of the subcellular localisation of phospholipase A1 and A2 and to acyl-CoA: 1-acylglycero-3-phosphorylcholine-0-acyltransferase.

After cell disruption differential centrifugation was followed by additional sucrose gradient purification of three main fractions.

Satisfactory enrichment factors were obtained by this method for the following marker enzymes. The plasma-membrane enzyme alkaline phosphodiesterase I was enriched up to 25-fold and the acyl-CoA:1-acylglycero-3-phosphorylcholine-0-acyltransferase was enriched up to 30-fold. The marker enzyme for the endoplasmic reticulum, NADPH-cytochrome c reductase showed a similar enrichment and distribution as the acyltransferase. Therefore it was concluded that the acyl-CoA:1-acylglycero-3-phosphorylcholine-O-acyltransferase of bone marrow-derived macrophages is mainly located in the endoplasmic reticulum. Phospholipase A1 and A2 occurred in a high proportion together with the lysosomal marker enzyme N-acetyl-β-glucosaminidase in the soluble supernatant and in the gradient fractions. In the endoplasmic reticulum phospholipase A2 occurred only in trace activities whereas phospholipase A 1 was maximally enriched in this subcellular fraction. No subcellular fraction could be obtained where phospholipase A2 was enriched exclusively. However, it can be concluded that the two enzymes which are responsible for the balance of fatty acid liberation and re-acylation are located in two different cellular compartments. Furthermore it can be claimed that in the cell there has to exist an exchange of substrates and products between these compartments to achieve a complete metabolic cycle of the de-and re-acylation reaction of phospholipids in bone marrow-derived macrophages.
Spurorientierung bei Waldameisen (Formica polyctena Förster) / Trail Orientation of Wood Ants (Formica polyctena Förster)
Authors: Horstmann K.
Published: August 2018

Workers of Formica polyctena Förster (Hymenoptera, Formicidae) follow artificial trails made with the contents of mandibular glands, poison glands, Dufour glands and rectal glands of their own species, as well as recruitment trails of Lasius fuliginosus (Latreille) or Myrmica ruginodis Nylander. Some specialized out-door workers prefer poison trails, as do workers irritated by a marking procedure. After withdrawal of sugared water the workers prefer rectal trails. Workers of hungry colonies also follow trails made with sugared water or faeces of tortricid larvae.
Biosynthesis of Isoflavonoid Phytoalexins: Incorporation of Sodium [1,2-13C2] Acetate into Phaseollin and Kievitone
Authors: Dewick Paul M. , Steele Melanie J. , Dixon Richard A. , Whitehead Ian M.
Published: August 2018

13C-NMR analysis of the isoflavonoid phytoalexins phaseollin and kievitone produced by feeding sodium [1,2-13C2]acetate to wounded bean (Phaseolus vulgaris) cotyledons has demonstrated the incorporation of intact acetate units into the aromatic A rings. Phaseollin shows a specific folding of the polyketide chain, whereas kievitone exhibits a randomisation of label in accordance with the intermediacy of a 2′,4′,6′-trihydroxylated chalcone during its formation. In neither case was sufficient label incorporated into analysis.
Effects of Trypan Blue and Related Compounds on Production and Activity of Streptolysin S
Authors: Taketo Yoriko , Taketo Akira
Published: August 2018

Most dyes related to trypan blue inhibited hemolytic activity of oligonucleotide-streptolysin S (SLS) complex, an exotoxin produced by Streptococcus pyogenes. Order of the inhibition was: trypan blue > benzo blue 2B > Congo red > Evans blue > benzo purpurine 4B > thiazine red > trypan red. When resting streptococcal cells were incubated with these dyes, significant amount of the hemolysin was produced. The carrier (or inducing) activity for SLS was further manifested in growing cell system and the potency of the compounds was as follows: Congo red > benzo blue 2B > trypan blue > Evans blue > Benzo purpurine 4B > thiazine red > trypan red. In this system, Congo red was more effective than oligonucleotide fraction rich in guanyl residue. Chromotrope 2B, H acid and o-tolidine were ineffective, as the carrier as well as the inhibitor. Based on these results, structure-function relationship among SLS, the carrier and the inhibitor was discussed.
Equilibrium Constants for Some Steps of the Reaction Cycle of the Sarcoplasmic Reticulum Calcium Pump
Authors: Tanford Charles , Martin Dwight W.
Published: August 2018

This paper summarizes true equilibrium measurements for some partial reactions of the sarcoplasmic reticulum calcium pump transport cycle. The most important result is the estimation of the equilibrium constant for the interconversion of the two major conformational states of the protein, E (Ca2+ binding sites facing the cytoplasm) and E′ (Ca2+ binding sides facing the sar­coplasmic reticulum lumen). The value of K0 = [E′]/[E] cannot be evaluated directly by any method available at present, but observed cooperativity in the binding of Mg2+ and Ca2+ to unliganded protein strongly indictes that K0 ⪢ 1. The most probable value, valid within an order of magnitude, is K0 ≃ 103, i.e., the E′ state is more stable than the E state by about 4 kcal/mol.
Roseanolone: A New Diterpene from Hypoestes rosea
Authors: Okogun Joseph I. , Adesomoju Akinbo A. , Adesida George A. , Lindner Hans Jörg , Habermehl Gerhard
Published: August 2018

Roseanolone is a new diterpene from the African plant Hypoestes rosea (Acanthaceae). The isolation is described; the structure has been determined to be 1,2,3,3a,4,5,6,6a,7,8,9,10a-dodecahydro-5-hydroxy-3-isopropyl-3a, 6-oxa-6,9,10a-trimethyl-dicyclopenta[a,d] cycloocten-1-one by X-ray crystallography.
Irregularities in the Circular Dichroism of Oligoribonucleotides
Authors: Zacharias Wolfgang , Follmann Hartmut
Published: August 2018

Marked anomalies, previously unresolved, exist in the CD spectra of oligoadenylates and oligouridylates at the pentamer or tetramer stage, indicating that these molecules differ in conformation from the preceding and the following member of the series. The CD of oligoadenylates retains a positive Cotton effect even at 80 °C. Caution must be exerted when predicting oligonucleotide structures from CD spectra.
Adult T-Cell Leukemia-Associated Antigen (ATLA): Detection of a Glycoprotein in Cell- and Virus-Free Supernatant
Authors: Yamamoto Naoki , Schneider Josef , Hinuma Yorio , Hunsmann Gerhard
Published: August 2018

A glycoprotein of an apparent molecular mass of 46000, gp 46, was enriched by affinity chromatography from the virus-and cell-free culture medium of adult T-cell leukemia virus (ATLV) infected cells, gp 46 was specifically precipi­tated with sera from patients with adult T-cell leukemia known to react with the adult T-cell leukemia associated antigen (ATLA). Thus, gp 46 is a novel component of the ATLA antigen complex.
Eine Röntgenkleinwinkelkamera ohne Spaltlängenverschmierung, II / Small-Angle-Scattering Camera without Slithigh-Error, II.
Authors: Wawra H.
Published: August 2018

A more detailed description o f the small-angle-X-ray camera without slithigh-error is given together with a calculation o f the beam condition and its influence on different scattering functions. Also the proceeding to measure molecular weights is described and some scattering curves are figured as an example of the equipments efficiency.
Elucidation of the Different Effects of Polyamines and Other Naturally-Occurring Inhibitors of Cell Proliferation (Chalones) on T-Lymphocyte and Granulocyte Colony Growth in vitro
Authors: Maschler R. , Smith C. J. , Allen J. C. , Maurer H. R.
Published: August 2018

Using T-lymphocyte and granulocyte colony assays with truly proliferating cells the effects of the polyamine spermine and of other naturally-occurring inhibitors of cell proliferation have been differentiated. It has been confirmed that spermine, in the presence of fetal calf serum, is a potent inhibitor of cell proliferation. This inhibition could be reversed by the addition of either 3- hydroxybenzyl-oxyamine or 4-bromo-3-hydroxybenzyl-oxyamine, both of which are inhibitors of the polyamine oxidase. In comparison, fractions isolated from calf thymus were shown to inhibit lymphocyte, but not granulocyte colony growth, indicating their tissue specificity and lymphocyte chalone activity. Further this inhibition was not reversed by polyamine oxidase inhibitors demonstrating that polyamines were not the inhibitory principles in this preparation.
Physical and Chemical Analyses of the Mineral Substance during the Development o f Two Experimental Cutaneous Calcifications in Rats: Topical Calciphylaxis and Topical Calcergy
Authors: Tochon-Danguy H. J. , Boivin G. , Geoffroy M. , Walzer C. , Baud C. A.
Published: August 2018

In subcutaneous calcinoses induced in rats by topical calciphylaxis and topical calcergy, the ultrastructural aspects related to the evolution of calcified deposits were previously described. In the present study by means of X-ray diffraction, infrared spectrometry and electron spin resonance, different biophysical analyses are performed on the mineral substance deposited during development of calciphylaxis and calcergy. A rapid evolution of the calcium phosphate deposits into hydroxyapatite was noticed along the first 20 days of the calcinoses; from then, there is no important modification even at the later stages, and the characteristics of the mineral substance are mostly similar to that of bone tissue. The concentration of trace elements such as Mg2+ and Fe2+, is found higher in cutaneous calcinoses than in bone tissue.
Ent-Kaurenoic Acid: A Diterpene as Frond Exudate on Ferns of the Genus Notholaena
Authors: Wollenweber Eckhard , Marx Dieter , Favre-Bonvin Jean , Brassy Claude
Published: August 2018

The frond exudates of the two gymnogrammoid ferns, Notholaena peninsular is and N. pallens, consist mainly of a diterpene, accompanied by small amounts of flavonoid aglycones. The diterpenes from both sources are shown to be identical. Their structure has been established by spectroscopic methods as (-)-kaur-16-ene-19-oic acid. This result is confirmed by direct comparison with an authentic sample.
Identification of two Gossypetin Monomethyl Ethers as Yellow Flower Pigments in the Rutaceae
Authors: Harborne Jeffrey B. , Boardley Marian
Published: August 2018

Gossypetin 7-methyl ether 3-rutinoside has been characterized as a yellow flower pigment in Ruta graveolens and in five other Ruta species. By contrast, in four Haplophyllum species, the 7-glucoside of gossypetin 3′-methyl ether provides the yellow coloration in the flower. Although carotenoid accompanies the yellow flavonol in R. graveolens, there is no evidence of UV patterning and the petals are uniformly UV absorbing.
Site of Action of Growth Inhibitory Tryptophan Analogues in Catharanthus roseus Cell Suspension Cultures
Authors: Sasse Florenz , Buchholz Marita , Berlin Jochen
Published: August 2018

Fourteen tryptophan analogues have been characterized with regard to their growth inhibitory effects on Catharanthus roseus cell cultures, their inhibitory effect on anthranilate synthetase, their incorporation into protein and their substrate affinity to tryptophan decarboxylase. The toxicity of 12 of the analogues was directly correlated with their inhibitory effect on anthranilate synthetase activity. None of the analogues was efficiently incorporated into protein. Only 4 of the analogues (4-methyl-, 4-fluoro-, 5-fluoro- and 5-hydroxytryptophan) were good substrates for tryptophan decarboxylase while all other analogues were rather poor substrates or were not converted at all. Alpha-methyltryptophan was a competitive inhibitor of tryptophan de­carboxylase
The Phycobihproteids in Cyanophora paradoxa as Accessoric Pigments and Nitrogen Storage Proteins
Authors: Schenk Hainfried E. A. , Hanf Jürgen , Neu-Müller Margarete
Published: August 2018

The phycobiliproteids of cyanobacteria have two functions. They are accessoric pigments for the light-dependent photosynthetic electron transport, and, secondly, they are storage proteins. Cyanocyta korschikoffiana, the endocyanelle of Cyanophora paradoxa, a hardly adapted endocytobiotic cyanobacterium, is responsible for the photoautotrophy of the host flagellate. The biosynthesis of the phycobiliproteids takes place in the endocyanelles and is reversible. Under nitrogen starvation the phycobiliproteids were disintegrated again, in contrast to the carotenoids (and in a lower degree to chlorophyll), whose contents rem ain more constant in the cells, as shown by in vivo measurements. Therefore, it is concluded that sim ilar to the function in free living cyanobacteria the phycobiliproteids of C. paradoxa also serve as storage substances (“stress proteins”). This opinion is supported by experiments with chloramphenicol
Der Einfluß von Cycloheximid und Chloramphenicol auf die Biosynthese der Photosynthese-Pigmente in Cyanophora paradoxa Korsch. II. carotinoide / The influence of cycloheximide and chloram phenicol on the biosynthesis of the photosynthetic pigments in cyanophora paradoxa. II. carotenoids
Authors: Neu-Müller Margarete , Schenk Hainfried E. A. , Stransky Harald
Published: August 2018

To prove the extent to which the endocyanelle of C. paradoxa is autonomous with respect to the biosynthesis of its photosynthetic pigments, the degree, to which the translation inhibitors cycloheximide (CHI) and chloramphenicol (CA) influence the biosynthesis of carotenoids, was investigated by two methods (in vivo VIS-spectroscopy and photosynthetic l4C-incorporation into the pigments). During the first 6 h (in vivo VIS-spectra) the probes treated with the inhibitors show a similar increase of the total carotenoid content as the control, thereafter the inhibition by CHI is increased significantly at approx. 50% (18 h), by CA somewhat lower. The [14C]carbon- dioxide incorporation into β-carotene do not show any notable differences between the control culture and the cultures treated with inhibitors. Quite different to this observation is the behaviour of zeaxanthin. CHI shows an inhibition of 60% after 8 h, whereas CA accelerates the biosynthesis of zeaxanthin at +60% (to the control). Zeaxanthin has the same absolute concen­tration, but it was marked only ten times lower than β-carotene. The greater effect of CHI (in vivo VIS-spectra) should not be taken as a higher participation of the eukaryotic genome. In contrast that is only to ascribe to the inhibition of the photosynthetic activity, which is in the same order of magnitude. Additionally the behaviour of zeaxanthin seems to be more a sign for higher participation of the prokaryotic genome
Der einflub von cycloheximid und chloramphenicol auf die biosynthese der photosynthese-pigmente in cyanophora paradoxa korsch. III. chlorophyll a und phycochromoproteide / The influence of cycloheximide and chloramphenicol on the biosynthesis of the photosvnthetic pigments in cyanophora paradoxa. III. chlorophyll a and phycochromoproteids
Authors: Neu-Müller Margarete , Schenk Hainfried E. A.
Published: August 2018

The inhibition effects of CHI and CA on the biosynthesis of the tetrapyrrolpigments were measured with two methods (in vivo VIS-spectroscopy, for chlorophyll (Chi) and the phycochromoproteids, 14C incorporation only for Chi). In the case of the Chl-biosynthesis both methods show the same results: a) In vivo VIS-spectroscopy demonstrates that the inhibition effect of CA manifests faster than that of CHI, b) during the 14C incorporation into Chi chloramphenicol (CA) inhibits more than cyclohexim ide (CHI) in contrary to the behaviour of chloroplasts. It seems that the CHI caused decrease of 14C incorporation into Chi can be ascribed to the decreased photosynthesis. The influence o f the antibiotics of the phycochrom oproteids is similar to that observed for chlorophyll. It is remarkable that under the influence of CHI the phycochromoproteid biosynthesis is significantly better than under CA influence, although CHI damages the consortium more than CA. That can be interpreted, as for chlorophyll, with a more endocytobiont coded phycochrom oproteid synthesis
Enzymatic Removal of O6-Ethylguanine versus Stability of O4-Ethylthymine in the DNA of Rat Tissues Exposed to the Carcinogen Ethylnitrosourea: Possible Interference of Guanine-O6 Alkylation with 5-Cytosine Methylation in the DNA of Replicating Target Cells
Authors: Müller Rolf , Rajewsky Manfred F.
Published: August 2018

In order to compare the kinetics of their enzymatic elimination from the DNA of liver, kidney, lung, and brain, the alkylation products O4-ethyl-2'-deoxythym idine (O4-EtdThd) and O6-ethyl- 2'-deoxyguanosine (O6-EtdGuo) were quantitated by competitive radioimmunoassay over a period of 48 h after a single pulse of the carcinogen N -ethyl-N-nitrosourea (EtNU ) applied i.p. to 10 and 28-day-old BDIX-rats. The content of O4-EtdThd in the DNA of all organs analyzed remained stable, while O6-EtdGuo (initially formed in DNA with 3 - 4 times higher frequency than O4-EtdThd) was rapidly removed from the DNA of liver, followed by lung and kidney, but persisted strongly in the DNA of brain. At 48 h after the EtNU -pulse, the O4-EtdThd content of liver DNA exceeded the O6-EtdGuo content by about a factor of 4. Since both O6-EtdG uo and O4-EtdThd are miscoding DNA lesions, the lack of enzymatic removal of O4-EtdThd is surprising in view of the apparent concern of cells to restore the integrity of the Opposition of guanine. Genetic consequences more specifically connected with the formation of O6-alkylguanine in DNA might be considered, e.g., possible alterations of gene expression via interference with enzymatic 5-cytosine methylation in 5'-CpG-3' sequences of newly replicated DNA
Ein neues kulturverfahren für trichoplax adhaerens f. e. schulze / A new cultural method for trichoplax adhaerens f. e. schulze
Authors: Grell Karl G.
Published: August 2018

The primitive metazoon, Trichoplax adhaerens (Placozoa), can easily be cultivated with Nauplius larvae of the brine shrimp, Artemia salina, killed by heating, as food organism
Biosynthesis of 6a-hydroxypterocarpans: deuterium nmr evidence for direct hydroxylation of pterocarpans
Authors: Banks Stephen W. , Dewick Paul M.
Published: August 2018

2H-NMR analysis of the 6a-hydroxypterocarpan phytoalexin pisatin derived in CuCl2-treated pea (Pisum sativum) pods from [6,11a-2H2]maackiain has demonstrated the retention of all 2H labels. This establishes that no pterocarp-6a-ene or pterocarp-6-ene intermediate is involved, and thus confirms a direct 6a-hydroxylation mechanism for the biosynthesis of 6a-hydroxypterocarpans from pterocarpans
Chemotypen bei Molopospermum peloponnesiacum (L.) Koch / Chem otypes o f molopospermum peloponnesiacum (L.) Koch
Authors: Kubeczka K.-H. , Ullmann I.
Published: August 2018

The investigation of Molopospermum peloponnesiacum (L.) Koch from different locations afforded two different types of essential oils: the first one is characterized by a relatively high content of trim ethylbenzaldehydes, whereas the other type contains relatively high amounts of dillapiole and nothapiole
Evidence for Unequal Misses in Oxygen Flash Yield Sequence in Photosynthesis
Authors: Delrieu Marie-Jose
Published: August 2018

The numerical analysis of the oxygen flash yield Yn sequences, alone, does not allow to choose between two models: equal S state misses with non negligible double hits or unequal misses with nearly no double hits. Nevertheless, the comparison of the sequences in different conditions shows that the equal miss model is unrealistic: in very different experimental conditions (non saturating flash, different batch of Chlorella or chloroplasts), a parallel variation of the homogeneous miss and double hit factors is observed. This correlation seems strange within the equal miss model: misses come from incomplete reaction (i.e. for exemple insufficient light) and double hits i.e. double advancement come, in principle, from excessive light or too long flash; for these reasons, opposite variation of misses and double hits as a function of light intensity are expected. Within the equal miss model the inverse is exactly observed: at low flash light intensity (11%) which increases the misses, 16% of double hits are needed, which is quite unrealistic. In contrast, the unequal miss model explains such result quite naturally by a m athem atical property: any theoretical sequence with only a unique S state miss and no double hit can be fitted with homogeneous misses and double hits, which increase in parallel as a function of the damping. Evidence for unequal misses in oxygen flash yield sequence is provided by the heterogeneous properties of the light saturation curves (M. J. Delrieu, Biochim. Biophys. Acta 592, 478-494 (1980)). At high flash intensity, all, excepted the transition S'2 → S3, are saturated; the transition S'2-→S3 is far from saturation and its very large saturating light intensity is actually not known. A comparative study, in the same chloroplast batch, of the oxygen yield patterns with attenuated flashes and of the experimental saturation curves of S states shows that only photochemical misses (due to non saturation) exist. At high intensity, there is only a unique miss for the transition S2→S3 i.e. the probability for this transition is low. A model involving a second acceptor could explain the slow increase of transition probability of S'2→S3 at high flash intensity
Calorimeter-Fermentor Combination for Investigations on Microbial Steady State Cultures
Authors: Leiseifer H. P. , Schleser G. H.
Published: August 2018

The combination of a 3-liter fermentor with a flow-through calorim eter is described. Minimum time-lags are less than 10 s corresponding to maximum therm al peak disturbances of ~ 4 μW. The set up shows an excellent long time stability. Aerobic growth of Escherichia coli K12 in batch cultures was used to test the equipment. Precision is ± 2.1% with regard to the total heat release of 4.94 kJ • I-1 and ± 2.5% with respect to the maximum heat flow of 609 mW • l-1. The accuracy is comparable with calorimeters using commercial flow mixing cells
Characterisation of the Enzyme Intermediates of the Sarcoplasmic Transport ATPase by the Use of Inhibitors
Authors: Boll W. , Makinose M.
Published: August 2018

1. Based on a detailed reaction scheme of the phosphorylation process of the sarcoplasmic transport ATPase the inhibition mechanisms of benzoctamine, DIO 9, AMP-PNP and of Ca2+-ions at relatively high concentrations (1 ~ 100 μᴍ) were determined.

2. The inhibition mechanisms were analyzed by measuring the γ-phosphate exchange between ATP and ADP and evaluated by applying conventional and an extended Dixon plot procedures.

3. The kinetic patterns of the inhibition were shown to be compatible with the assumed reaction scheme.

4. Each inhibitor combines with definite intermediates: Benzoctamine with the interm ediate species

~ P; DIO 9 with E and MgE and Ca2+ at relatively hign concentrations with E.

5. The central interm ediate blocked by benzoctamine can partially exist as

-benzoctamine which is detected as phosphoprotein after acid denaturation
The phytoalexin response of lathyrus sativus (grass pea)
Authors: Robeson David J. , Harborne Jeffrey B.
Published: August 2018

Lathyrus sativus was investigated for the nature of its phytoalexin response with the result that leaflets, immature pods, and seeds were induced to produce 6a-hydroxy- 3-methoxy-8,9-methylenedioxypterocarpan (pisatin). Evidence is presented for the metabolism of pisatin, by the wound pathogen Botrytis cinerea, to a phenolic congener, 3,6a-hydroxy-8,9-methylenedioxypterocarpan
Studies on the Regulatory Role of trans-Cinnamic Acid on the Activity of the Phenylalanine Ammonia-Lyase (PAL) in Suspension Cultures of Daucus carota L.
Authors: Noé W. , Seitz H. U.
Published: August 2018

In vivo and in vitro experiments were performed in order to study the regulatory role of trans- cinnamic acid and its hydroxylated derivatives (p-coumaric acid, caffeic acid) on the deamina­tion of phenylalanine catalyzed by PAL (EC 4.3.1.5). Trans-cinnamic acid inhibits growth and reduces the content of soluble proteins of anthocyanin-containing carrot cells grown in suspen­sion. There is strong evidence from the polysomal patterns and from the effect of trans-cinnamic acid on protein synthesis in vitro that protein synthesis is inhibited. The kinetic data of PAL clearly demonstrate that trans-cinnamic acid inhibits the enzyme by a noncompetitive mecha­nism. On the contrary, ʟ-α-aminooxy-β-phenylpropionic acid (ʟ-AOPP), a competitive inhibitor of PAL, does not affect protein metabolism.
Nitrate Reductase from a Mutant Strain of Chlamydomonas reinhardii Incapable of Nitrate Assimilation
Authors: Fernández Emilio , Cárdenas Jacobo
Published: August 2018

Nitrate reductase from mutant 305 of Chlamydomonas reinhardii has been purified about 90-fold and biochemically characterized. The enzyme can use reduced flavins and viologens as electron donors to reduce nitrate but, unlike the nitrate reductase complex from its parental wild strain, lacks NAD(P)H-nitrate reductase and NAD(P)H-cytochrome c reductase activities, does not bind to Blue-Agarose or Blue-Sepharose and exhibits a significantly lower molecular weight (177.000 vs. 241.000), whereas its kinetic characteristics and its sensitivity against several inhibitors and treatments are very similar to those of the terminal nitrate reductase activity of the wild strain complex. Spectral studies and antagonistic experiments with tungstate show the presence of cytochrome b557 and molybdenum. These facts lead us to propose that nitrate reductase from mutant 305 has a protein deletion which affects the pyridine nucleotide binding region of the diaphorase protein but without any effect on the terminal nitrate reductase activity.
A Specific and Sensitive Radioimmunoassay for Human Choriogonadotropin
Authors: Muralidhar K. , Chaudhuri G. , Lippes J. , Bahl O. P.
Published: August 2018

A specific and sensitive radioimmunoassay for human choriogonadotropin (hCG) has been developed using rabbit antiserum to chemical analogs of beta subunit of human chorionic gonadotropin prepared by controlled reduction and S-alkylation of its disulfide linkages. The assay was highly specific for hCG as the binding of [1251]-hCG to the antibody was not affected by standard human lutropin, by human male serum, postpartum serum from women, serum from post-menopausal women and human menopausal gonadotropin (Pergonal). The assay was highly sensitive, the minimal detection limit in terms of highly purified hCG (L-129, 12500 IU/mg) being 1 ng/ml or 0.2ng/tube (or 12mlU/ml in terms of WHO 2nd international reference preparation of hCG). Using this assay we were unable to detect any immunoreactive hCG in human tissues like lung, liver and colon. The high specificity, sensitivity, accuracy and repro­ducibility of the assay make this a highly desirable radioimmunoassay for human chorio­gonadotropin.
Electromagnetic Modulation of Biological Processes: Bicarbonate Effect and Mechanistic Considerations in the Ca-Uptake by Embryonal Chick Tibia in vitro
Authors: Colacicco Giuseppe , Pilla
Published: August 2018

Electromagnetically induced currents pulsating at very low frequency stimulated calcium uptake by chick embryo tibia rudiments only when bicarbonate was present in the culture medium. A bicarbonate-dependent Ca2+-ATPase might be implicated in coupling of the electromagnetic signal with processes that promote Ca-transport and storage in bone tissue.
Adsorbenskultur — ein Weg zur Steigerung der Sekundärstoffproduktion in pflanzlichen Suspensionskulturen / Adsorbent Culture -Method for the Enhanced Production of Secondary Substances in Plant Suspension Cultures
Authors: Knoop Bernd , Beiderbeck Rolf
Published: August 2018

A crown-gall suspension of Matricaria chamomilla L. was cultivated in the presence of an adsorbent (activated charcoal, AC). The culture produces besides other secondary products coniferyl aldehyde which is excreted by the cells and distributed between cells, medium, and the AC according to equilibrium distributions with more than 95% of the substance adsorbed to the AC. This deprivation of coniferyl aldehyde from the medium enables the cells to increase the production of this substance up to 60-fold.

The system Matricaria/coniferyl aldehyde serves as a model for the improvement of the production of secondary products by means of plant cell suspensions.
Chemical Composition of the Secretion from the Anal Sacs of Civettictis civetta (Schreber, 1776)
Authors: Jacob Jürgen , Schliemann Harald
Published: August 2018

The chemical composition of the secretion from the anal sacs of a female of Civettictis civetta is analysed using gas- liquid chromatographical and mass spectrometrical tech­niques. The secretion mainly consists of cholesterol esters, monoester waxes, cholesterol, and free fatty acids of chain lengths not under C12; highly volatile components were not traceable. The functional significance of the anal sac secretion is discussed. `
Regulation der Temperatur in Waldameisen- Nestern (Formica polyctena Förster) / Temperature Regulation in Wood Ant Nests (Formica polyctena Förster)
Authors: Horstmann K.
Published: August 2018

The interior of wood ant nests (Hymenoptera, Formicidae, Formica polyctena Förster) and artificial piles of nest material has been heated with heating wires in the field. In the artificial piles a heating power of 1 - 5 Watt is suffi­cient to cause a temperature increase equivalent to that caused by ants in their nests without additional heating. Whereas in artificial piles temperatures increase with in­creasing heating power, the ants prevent temperatures to exceed 34.6 degrees C in their natural nests, even if these are heated with a power of more than 20 Watt.
Nitrogen Fixation and Nitrate Respiration by A zospirillum brasilense
Authors: Bothe Hermann , Barbosa Gislene , Dobereiner Johanna
Published: August 2018

The O2- sensitivitiy of N2-fixation by the carotenoid forming strain Azospirillum brasilense Cd and the colourless strain Sp 7 is compared in the present communication. As no difference in the reaction is observed with both strains, it is concluded that carotenoids do not protect nitrogenase from damage by O2. Azospirillum spp. have also been shown to perform NO3
-- dependent N2-fixation. The physiological properties of this reaction are described in more detail in the present communication. Evidence is presented that NO3
-- dependent N2-fixation is a transitory reaction, proceeding only as long as the enzymes of assimilatory nitrate reduction are synthesized by the cells.
Flavonoids from the Leaf Resin of Hymenoclea salsola T. & G. (Asteraeeae)
Authors: Proksch Peter , Wollenweber Eckhard , Rodriguez Eloy
Published: August 2018

Hymenoclea salsola (Asteraceae), a dominant shrub of the desert areas of California and Baja California, Mexico, secretes high amounts of resin on the leaf surface. Chemi­cal analysis of the resin revealed the presence of a complex mixture of flavonoid aglycones. Among the compounds identified is the rare 2',4',6'-OH chalcone, previously not known to occur in the Asteraceae.
Time-Shifted Mating Periods in Two Closely Related Corixid Species
Authors: Theiß Joachim
Published: August 2018

The water boatmen Corixa dentipes and C. punctata produce an acoustic mounting signal when beginning to copulate. Automated recording of this signal over the entire life cycle of the anim als reveals that the main mating period of C. punctata occurs in autumn and that of C. dentipes, in the spring. In the case of C. punctata, mounting signals were routinely recorded even during the winter, at water temperatures below 4 °C.
Chemistry and Morphology of Epicuticular Waxes from Various Organs of Jojoba (Simmondsia chinensis [Link] Schneider)
Authors: Gülz Paul-Gerhard , Hängst Kurt
Published: August 2018

The surface of leaves and seed coats of Jojoba is covered with similar amounts of epicuticular waxes per surface area. The composition of these waxes was analysed by chemical methods, whereas their microscopic structures in situ were revealed by scanning electron microscopy. Differences in the chemical structure and com position of the complex mixtures cause differences in the morphological appearance of wax on the surface of both organs. The predominance of saturated and long chain components in leaf wax results in a crystalline wax layer on this organ. In contrast, the seed coat carries a cover of non-crystalline fluid consistency. The lower melting point of this wax mixture is caused by shorter chain and unsaturated compounds predominating on this organ.
Isolation and Structural Determination of a New Methylated Triterpenoid from Rhizomes of Iris versicolor L.
Authors: Krick Wolfgang , Marner Franz-Josef , Jaenicke Lothar
Published: August 2018

A monocyclic C31-triterpenoid was isolated from rhizomes of Iris versicolor L. Its structure was elucidated as 12 by spectroscopy combined with oxidative degradation. The identity of the degradation-products was proven by comparison with synthetic references.
Kinetin-Mediated Stimulation of Accumulation of Buckwheat Flavonoids in the Dark
Authors: Margna U. , Vainjärv T.
Published: August 2018

A short treatment of excised buckwheat cotyledons with a solution of kinetin lead to an up to 9-fold stimulation of anthocyanin biosynthesis, to an about 50 percent increase in the accumula­tion of rutin, and to an about 30 percent increase, on the average, in the accumulation of C-glycosylflavones in the treated material during its posttreatment incubation in the dark. When the treated cotyledons were incubated in a solution of ʟ--phenylalanine anthocyanin accumulation in the dark practically attained the same high level as it was observed in the illuminated cotyledons fed with exogenous ʟ--phenylalanine. In experiments with l4C-labelled L-phenylalanine kinetin induced a sharp rise in the labelling (resp. in the utilization of exogenous substrate for biosynthesis) of anthocyanins and rutin in the dark and a slight increase in the radioactivity of C-glycosylflavones. Similar labelling changes occurred in the illuminated cotyledons. However, both kinetin and light still more effectively promoted biosynthetic use of the endogenous sub­strate. As a result the relative portion of flavonoids formed from exogenous L-phenylalanine under these conditions showed a decrease as compared with the ratio of precursor use in the un­treated cotyledons. The results show that low accumulation rates of anthocyanins and other flavo­noids in the dark are conditioned by the limited access of substrate (ʟ--phenylalanine) molecules to the flavonoid enzymes lending further support to the idea that flavonoid biosynthesis is normally controlled at the substrate rather than at the enzymic level.
Urobiliverdin, a New Bile Pigment Deriving from Uroporphyrin
Authors: Benedikt Eva , Köst Hans-Peter
Published: August 2018

5-Aminolevulinic acid is incubated with a crude enzyme extract from Rhodopseudomonas spheroides, mutant R 26. The formed porphyrins (main product: uroporphyrin III) are isolated. Incorporation of iron, ring-splitting by coupled oxydation and subsequent iron removal leads to a mixture of pigments, from which urobiliverdin, a new bile pigment with eight carboxylic acid side chains, is isolated. It is characterized by its chromatographic behaviour, chromic acid degra­dation and UV-vis spectroscopy.
Structure Activity Correlation of Herbicides Affecting Plastoquinone Reduction by Photosystem II: Electron Density Distribution in Inhibitors and Plastoquinone Species
Authors: Trebst A. , Donner W. , Draber W.
Published: August 2018

Molecular orbital calculations of the net charge and the π charge distribution in several inhibitors and herbicides of the functionally related group of the diuron and dinoseb type are reported. They confirm the model that urea, aminotriazinone and triazine herbicides all have in common a positive π-charge at a particular atom considered to be essential for binding. Phenol type inhibitors have different charge distribution and a model for their essential features is presented. The calculations support the finding that two different subunits with different binding characteristics are involved in inhibitor and plastoquinone function on the acceptor side of photosystem II.

Force-field model building and MO calculations of the charge distribution of a plastoquinone analogue with a butenyl side chain, of two of its semiquinone forms and of the hydroquinone, are reported, as well as their conformation with the lowest energy content and their likely anionic forms.
Comparison of the Action of Bleaching Herbicides
Authors: Feierabend Jürgen
Published: August 2018

Among chlorosis-inducing herbicides that interfere with carotenoid synthesis two groups of different potency can be discriminated (group 1: aminotriazole amd haloxidine; group 2 with more extensive photodestructions: pyridazinone herbicides and difunon). After application of herbicides of group 2 colored carotenoids were completely absent and preexisting chlorophyll was degraded by photochemical reactions requiring high light intensity and O2, that occurred also at 0°C. In treatments with group 1 herbicides direct photodegradation of chlorophyll was not sufficient to generate the chlorosis. Light-induced interference with constituents of the chloroplast protein synthesis apparatus being more sensitive to photooxidative damage than chlorophyll, appeared to indirectly mediate the chlorosis. In the absence of chloroplast protein synthesis further chlorophyll accumulation is prevented. Photodegradation of chlorophyll in the presence of group 2 herbicides involved the participation of O2
- radicals and was accompanied by lipid peroxidation. In all herbicide treatments the catalase activity of the leaves was very low. Only in the presence of group 2 herbicides chloroplast enzymes of cytoplasmic origin (e.g. NADP-glyceraldehyde-3-phosphate dehydrogenase) were also inactivated. Rapid inactivation of catalase as well as of NADP-glyceraldehyde-3-phosphate dehydrogenase was induced by exposure of dim-light-grown herbicide-treated leaves to bright light, also at 0°C. In treatments with herbicides of group 2 also other peroxisomal enzymes (e.g. glycolate oxidate, hydroxy-pyruvate reductase) were affected. The elimination of these peroxisomal enzymes also appeared to depend on photooxidative processes of the chloroplast.
Radical Formation and Peroxidative Activity of Phytotoxic Diphenyl Ethers
Authors: Lambert Rolf , Kroneck Peter M. H. , Böger Peter
Published: August 2018

Phenyl-t-butylnitrone can be used to trap light-induced radicals with isolated chloroplasts, measurable by ESR technique. The radical signals are dramatically amplified and their lifetime prolonged in the presence of peroxidizing diphenyl ethers. A para-substitution with -NO2, - Cl-or - I is necessary, as well as an operating photosynthetic electron transport. The nature of radicals is not yet clear; they may be alkyl or linolenic-acid radicals, but their presence indicates peroxidation. Furthermore, the ESR measurements presented strengthen our hypothesis that peroxidative activity of paraquat and diphenyl ethers are not caused by the same mechanism.
Physiological Changes in Matricaria inodora Following Ioxynil and Bromoxynil Treatment
Authors: Sanders Gina E. , Cobb Andrew H. , Pallett Kenneth E.
Published: August 2018

A range of biochemical and physiological changes were monitored in Matricaria inodora following field rate applications of ioxynil and bromoxynil. Bromoxynil showed greater phytotoxicity with decreased reducing sugars, amino acids and proteins occurring within 28 days of treatment, when plant death was apparent. After an initial decline these parameters increased as plants appear to recover from ioxynil treatment. CO2 fixation was completely inhibited within 4 days in leaves treated with ioxynil and bromoxynil. Ultrastructural effects of both herbicides were similar with chloroplast swelling, decrease in starch grains and thylakoid disruption prior to cellular destruction. In vitro activity of the herbicides on isolated chloroplasts revealed ioxynil to be slightly more inhibitory than bromoxynil toward electron transport and approximately one hundred times more effective as an uncoupler of PMS cyclic photophosphorylation.
Increased Synthesis of Photosystem II in Triticum vulgare when Grown in the Presence of BAS 13-338
Authors: Bose Salil , Mannan R. Mannar , Arntzen C.J.
Published: August 2018

Addition of BAS 13-338 (4-chloro-5-dimethylamino-2-phenyl-3(2H)-pyridazinone) to a suspension of chloroplast thylakoids caused an increase in the / level of chlorophyll fluorescence induction without affecting the F0 level and with a slight decrease in the Fmax level in a manner similar to the addition of DCMU to a thylakoid suspension. Addition of BAS 13-338 also inhibited the rate of Hill reaction H2O → dichlorophenol indophenol with 50% inhibition occurring at about 10 μм BAS 13-338. The inhibition was not reversed by diphenyl carbazide used as an artificial electron donor to photosystem II. These results suggest that the site of inhibition by BAS 13-338 is between Q (next to the primary electron acceptor) and plastoquinone.

When the plants were grown in the presence of sublethal dose of BAS 13-338, the following changes were noted in the thylakoids of the treated plants as compared to the thylakoids isolated from the control plants: The F0 and the normalized variable fluorescence (⊿F/F0) levels increased, chlorophyll a/b ratio decreased, chlorophyll/P700 ratio increased. Furthermore, the rate of photosystem II electron transport both under saturated intensity and the limiting intensity of illumination increased, and the ratio of plastoquinone to Q decreased. These observations have been interpreted as due to an increase in the ratio of photosystem II to photosystem I in plants grown in the presence of BAS 13-338.
Common Identity of UDP-Glucose: Anthocyanidin 3-O-Glucosyltransferase and UDP-Glucose: Flavonol 3-O-Glucosyltransferase in Flowers of Petunia hybrida
Authors: Jonsson L. M. V. , Aarsman M. E. G. , Bastiaannet J. , Donker-Koopman W. E. , Geräts A G. M. , Schram A. W.
Published: August 2018

In an attempt to distinguish between the UDP-glucose: flavonol 3-O-glucosyltransferase (3GT) and the UDP-glucose: anthocyanidin 3-O-glucosyltransferase in flower buds of Petunia hybrida, several properties of these activities were determined. The 3-glucosylation of anthocyanidin had a pH-activity optimum of 7.2, that of flavonol pH 9.2 to 9.5. Anthocyanidin 3GT activity was lowered in the presence of EDTA or β-mercaptoethanol, but this was due to an effect on the anthocyanidin substrate. The two 3-glucosylating activities were to a similar extent inhibited by an increasing ionic strength in the enzyme assay and showed an identical iso-electric point (5.2) as determined by chromatofocusing. Molecular weights were identical: 26000, 52000 or 78000 daltons as determined by gel-filtration. Antiserum raised against partially purified 3GT gave identical immunoprecipitation curves with flavonol 3GT and anthocyanidin 3GT.

Special attention was given to the 3-O-glucosyltransferase in mutants with low levels of 3GT activity. These mutants are unable to form significant amounts of anthocyanins but contain wild- type amounts of flavonols. The enzyme of such mutants had the same iso-electric point and identical titration-curves with antiserum as the enzyme from wildtype plants. 3GT from wildtype or mutant plants glucosylated flavonols at higher rates than anthocyanidins.
Über die pH-induzierte Inaktivierung der Glycerindehydrogenase aus Bacillus megaterium / pH -Induced Inactivation of Glycerol Dehydrogenase from Bacillus megaterium
Authors: Ganzhom Axel , Scharschmidt Margrit , Pfleiderer Gerhard
Published: August 2018

The kinetic of the reversible dissociation of glycerol dehydrogenase from Bacillus megaterium in slightly alkaline medium was measured by biochemical, chemical and physical methods. The dissociation is followed by changes in the secondary structure and can be prevented by addition of NAD or increased potassium chloride concentration. Crosslinking by suberimidate, but not by monofunctional imido esters, shows a high stabilization against alkali, urea or heat inactivation caused by hindrance of dissociation.