bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective Role of Trehalose in Thermal Denaturation of Yeast Pyrophosphatase
Authors: Sola-Penna Mauro , Meyer-Fernandes José Roberto 
Published: August 2018

Abstract
Thermal Denaturation, Trehalose, Yeast Pyrophosphatase, Water Activity, Carbohydrates Trehalose, a disaccharide of glucose, is accumulated in yeast cytosol when this organism is submitted to a stress condition. Recently it was shown that the level of trehalose increase up to 15 times when yeast cells are submitted to heat shock (De Virgilio et al., 1991). In this report we give evidence how trehalose may play an important role on the stress-survival of yeasts when submitted to a heat shock. We show that 1.5 M trehalose increases 13-fold the half-time for thermal inactivation (t0.5) of yeast cytosolic pyrophosphatase at 50 °C. This thermal pro­tection conferred by trehalose is dose-dependent, after 10 min at 50 °C, a condition which inactivated pyrophosphatase, the presence of 2 M trehalose preserves 95% of total activity. Other carbohydrates were tested but were not so effective as trehalose. The presence of tre­halose at high concentrations in the reaction medium at 35 °C inhibits pyrophosphatase activity. This inhibition is less effective at 50 °C suggesting that under this condition the enzyme is temperature-protected and active.
Temporal Changes of the Lipid Peroxidation in Rats after Acute Intoxication by Ethanol
Authors: Charles Zdenek Zloch 
Published: August 2018

Abstract
received October 23, 1993/March 1, 1994 Ethanol, Microsomes, Mitochondria, Lipid Peroxidation, Hepatotoxicity A group of male rats were intoxicated within 24 h by three successive i.p. doses of ethyl alcohol (7.5 g per 1 kg of the body weight). In parallel, a control group of rats were dosed i.p. with a physiological saline. At time intervals of 0 h, 4 h, 24 h, and 48 h after the intoxi­ cation, the content of thiobarbiturate-reactive substances (TBARS) as product of lipid per­ oxidation within the liver and brain microsomes and mitochondria was followed.
In liver microsomes of the experimental rats there was a rapid increase (by 220%) in the content of TBARS during 4 h after the last application of ethanol, later on the level of lipid peroxidation decreased to the low original value. In other organelles examined only an insignificant increase in the content of TBARS was found. The results prove that an acute intoxication by ethanol does elicit an oxidative stress of the organism, expressed by a tran­siently increased production of TBARS. These oxidative and harmful changes for the cell structures are mostly located in the liver microsomes but a rapid repair of this damage fol­ lows. However, if such a short-term excessive abuse of alcohol is repeated more often, the above changes may lead to severe alcoholic injury
Localization of the Pupal Melanization Reducing Factor of Inachis io (L.) and Comparison with Melanization and Reddish Coloration Hormone
Authors: Starnecker G. , Koch P. B. , Matsumoto S. , Mitsui T. , Bückmann D. 
Published: August 2018

In Inachis io, a pupal melanization reducing factor (PMRF) which controls morphological color adaptation is located in the brain, suboesophageal ganglion, thoracic ganglia, and all abdominal ganglia. Higher PMRF amounts were extracted from abdominal ganglia than from the anterior ganglia. No PMRF activity could be found in the Corpora cardiaca-Corpora allata complex, in segmentally branching nerves of abdominal ganglia and their connectives.
Extracts from brain-thoracic ganglia and abdominal ganglia complex of I. io contained also a factor with melanization and reddish coloration hormone (MRCH) activity in Pseudaletia separata and with pheromone biosynthesis activating neuropeptide (PBAN) activity in Bom-byx mori. However, injection of synthetic Pseudaletia pheromonotropin (Pss-PT) (= Pss-MRCH) into prepupae of I. io did not yield a melanization reducing effect. Therefore, PMRF and the PBAN/MRCH related neuropeptides seem to be different molecules. The PBAN-like factor from I. io is possibly related to the myotropins and pyrokinins of insects
Diethyl Phosphate Binding to Mitochondrial Cardiolipin after Intraportal Infusion in Rats
Authors: Schole J. , Schole Chr. , Eikemeyer J. 
Published: August 2018

Abstract
20 min after intraportal infusion of diethyl phosphate (DEP) in rats, the mitochondrial cardiolipin (CL; 1,3-bisphosphatidyl glycerol) fraction is labelled with DEP. The obtained mixture of CL and DEP-labelled CL, which up to now has not been separated, behaves chromatographically (fractogel; HPLC; TLC), in respect to release of DEP and also in respect of the 31P NMR spectrum as a mixture of CL and cardiolipin ketone diethylenol phosphate. The latter compound was also obtained by photochemical reaction of CL ketone with diethyl phosphoric acid. After cautious hydrogenation (palladium charcoal) of the total mitochondrial lipid fraction of rats treated with DEP and subsequent extraction with NaCl solution (0.005 mol/1), glycerol-2-DEP has been identified in the water phase. It is supposed that this phosphoric acid derivative is formed from CL-DEP by elimination of two molecules of phosphatidic acid.
Kinetics and Regulation of the NAD(P)H-Dependent Glyoxylate-Specific Reductase from Spinach Leaves
Authors: Kleczkowski Leszek A. 
Published: August 2018

Abstract
Kinetic mechanism of purified spinach leaf NAD(P)H glyoxylate reductase (GR-1) was studied using either NADPH and NADH as alternative substrates with glyoxylate. The mech­anism was elucidated from substrate kinetic patterns using NADH as a cofactor rather than NADPH. With NADPH varied versus glyoxylate, and with NADPH and glyoxylate varied at a constant ratio, the patterns obtained on double reciprocal plots appeared to be consistent with a ping-pong mechanism; however, kinetic patterns with NADH conclusively ruled out the ping-pong reaction in favour of the sequential addition of the reactants. Product inhi­bition studies with glycolate and NADP have suggested either that NADPH binds to the enzyme before glyoxylate or that the addition of substrates is a random one. Studies with active group modifiers suggested an involvement of histidine, serine and cysteine residues in GR-1 activity. Salts had little or no effect on the activity of the enzyme, with the exception of cyanide, which had an apparent Ki of ca. 2 mᴍ. Studies with several metabolites used as possible effectors of GR-1 activity have suggested that the enzyme is modulated only by substrate availability in vivo. The apparent insensitivity of GR-1 to metabolic effectors is consistent with the proposed role of the enzyme in detoxifying glyoxylate which may act as a potent inhibitor of photosynthetic processes in plant tissues.
2,2-Dialkylacetic Acids -A New Class of Naturally Occurring Lipid Constituents
Authors: Raab Gottfried , Jacob Jürgen 
Published: August 2018

Abstract
The uropygial gland waxes of the South American red-legged Seriema (Cariama cristata (L., 1766)) were found to be composed of unbranched alcohols and 2,2′-dialkyl-substituted acetic acids which so far have not been found in skin lipids. When used as a chemosystematic character, the occurrence of this lipid class separates the order Cariamiformes (Seriemas) from all other avian orders hitherto investigated, especially from the Gruiformes (cranes and rails) to which they have been tentatively attributed in the past.
From the GC retention time data now available for a series of 2-alkyl-substituted fatty acid methyl esters relative retention time indices for other compounds may be predicted.
Evidence for a Cardenolide Carrier in Oncopeltus fasciatus (Dallas) (Insecta: Hemiptera)
Authors: Detzel Andreas , Wink Michael 
Published: August 2018

Abstract
Oncopeltus fasciatus (Hemiptera) is morphologically and physiologically adapted to seques­ter cardiac glycosides for its chemical defence against predators. As a prerequisite for carde­nolide utilization this bug has to take up and store the dietary cardenolides. Using isolated midguts it could be shown experimentally that the resorption of [3H]digoxin is time-, and temperature-dependent. The hydrogen ion concentration for uptake is optimal between pH 5.5 and 7 and an activation energy of 45 to 49 kJ/mol can be derived from an Arrhenius plot. Uptake can be inhibited competitively by the polar cardiac glycoside convallatoxin. Sulfhydryl group reagents (N-ethylmaleimide), membrane destabilizing compounds and respira­tory chain inhibitors reduce digoxin resorption, as do inhibitors of sugar transport (e.g., phloridzin). The experimental data thus provide evidence for a cardenolide carrier in midgut cells of O. fasciatus.
The Effect of γ-Hexachlorocyclohexane (Lindane) on the Activities of Liver Lipogenic Enzymes and on Serum Lipids in Rats
Authors: Boll Meinrad , Weber Lutz W. D. , Stampfl Andreas 
Published: August 2018

Abstract
The effect of dietary γ-hexachlorocyclohexane (lindane) (50 -350 ppm, 0.17-1.19 μmol/kg chow) on the activity of enzymes of lipogenesis, viz., fatty acid synthase (FAS; EC 2.3.1.85), citrate cleavage enzyme (CCE; EC 4.1.3.8), malic enzyme (ME; EC 1.1.1.40), glucose-6-phosphate dehydrogenase (G 6 PDH; EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (PGDH; EC 1.1.1.44), and on serum lipid levels, was investigated in livers of 35-day-old male Wistar rats.
Lindane (150 ppm) caused a substantial decline of enzyme activities within the first 24 h of treatment. The decrease was transient, however, and enzyme activities subsequently recov­ered despite continuation of lindane feeding. The recovery of enzyme activities was compara­ tively fast in the case of ME, G 6 PDH and PGDH, but very slow with FAS and CCE.
Activities of lipogenic enzymes decrease when animals are starved, and increase much beyond prestarvation levels upon subsequent refeeding. Lindane in the refeeding diet blunted this overshoot of FAS and CCE activities in a dose-dependent manner. In contrast, activities of ME, G 6 PD H and PGDH responded to low dietary lindane concentrations with a substantial stimulation of the increase of activity, whereas at high lindane concentrations the overshoot was inhibited.
According to their responses to lindane exposure, liver lipogenic enzymes could be grouped into 2 categories with FAS and CCE representing one and ME, G 6 PDH and PGDH representing the other group.
Polychlorinated biphenyls (PCBs) in the diet caused basically opposite changes of the activities of the lipogenic enzymes. Co-administration of lindane and PCBs resulted in an apparent cancellation of effects, suggesting that lindane and PCBs affect fatty acid synthesis at opposite points.
Levels of the serum triglycerides were increased significantly as a result of lindane feeding, while serum cholesterol and phospholipid levels were only slightly elevated. The increase of serum triglyceride levels that is routinely observed after refeeding of starved animals was stimulated even more by low concentrations of lindane in the refeeding diet, but inhibited by high concentrations.
Phylogeny of Old and New World Vultures (Aves: Accipitridae and Cathartidae) Inferred from Nucleotide Sequences of the Mitochondrial Cytochrome b Gene
Authors: Wink Michael 
Published: August 2018

Abstract
The molecular phylogeny of 11 Old World and 5 New World vultures was inferred from nucleotide sequences of the mitochondrial cytochrome b (cyt b) gene. According to this analysis carrion-feeding has evolved independently at least three times during evolution: 1.) In the New World vultures, which are clearly separated from vultures of the family Accipitridae; 2.) in the Neophron-Gypaetus clade which is positioned at the base of the Accipitrid tree and 3.) in the Gyps-Aegypius-complex which encloses the largest group of Old World vultures. Thus the genetic data clearly show that the carrion-feeding lifestyles and associated morphologies shared by New and Old World vultures are rather based on convergence than on close genetic relatedness. Employing the cyt b sequences of 12 other members of the Falconiformes and 10 members of the Ciconiiformes (sensu Sibley and Monroe, 1990) the phylogenetic relationship between the three clades of vultures and these other taxa was assessed. New World Vultures appear to share distant ancestry with storks but a close relationship is unlikely.
Structure and Characterization of Isopyoverdin from Pseudomonas putida BTP1 and Its Relation to the Biogenetic Pathway Leading to Pyoverdins
Authors: Jacques Ph. , Ongena M. , Gwose I. , Seinsche D. , Schröder H. , Delfosse Ph. , Thonart Ph. , Taraz K. , Budzikiewicz H. 
Published: August 2018

Abstract
Pyoverdin type siderophores produced by six fluorescent Pseudomonas strains isolated from different rhizospheres were purified and characterized. The purified ferri-pyoverdins were tested for their ability to promote the growth of other strains grown under iron deficiency conditions. Only the one obtained from Pseudomonas putida BTP1 did not act as a growth promoter.
The structure of the BTP1 siderophore was elucidated by spectroscopic methods and degradation studies. It turned out that it contains a chromophore which differs from the one typical for pyoverdins insofar as it carries the carboxyl group in 3- rather than in 1-position ((3S)-5-amino-1,2-dihydro-8,9-dihydroxy-3 H -pyrimido[1,2 a]quinoline-3-carboxylic acid). The amino group of the chromophore is substituted with the 5-carboxyl group of ʟ-glutamic acid and its carboxyl group with the N -terminus of the peptide ʟ -A sp -ʟ -A la-ʟ -Asp - ᴅ-N5- Ac - N5- OH - Orn - ʟ - Ser - ʟ - ᴄ - N5- OH - Orn . This isopyoverdin fits into the biogenetic scheme which postulates ferribactins as the precursors of pyoverdins
Kinetic Characteristics, Substrate Specificity and Catalytic Properties of Phosphoserine Aminotransferase from the Green Alga Scenedesmus obliquus, Mutant C-2A
Authors: Stolz M. , Dörnemann D. 
Published: August 2018

Abstract
Phosphoserine am inotransferase (EC 2.6.1.52) has been purified from Scenedesmus
obliquus. mutant C -2A′, as reported previously (Stolz and Dörnemann, 1994). The current studies on its catalytic properties, involving initial reaction velocities as a function of the phosphoserine concentration at various fixed concentrations of 2-oxoglutarate as aminoacceptor, indicate a bi-bi ping pong mechanism . The application of a variety of substrate analogues of phosphoserine revealed no significant metabolisation of these com pounds and thus a considerable specificity of the enzyme. 4,5-dioxovalerate with glutamate as am inodonor is effective as competitive substrate to phosphohydroxypyruvate in the forward reaction and yields 5-am inolevulinate.
4.5-Dioxovalerate and glutam ate-1-semialdehyde can both serve as competitive aminoacceptor in the reverse reaction with phosphoserine and as substrate with 2-oxoglutarate as am inoacceptor. Comparison of the phosphoserine transamination with the transamination of 4,5-dioxovalerate revealed for both reactions a pH -optim um of 6 .8 -7 .0 in Mes/Bis-Trisbuffer. How ever, the Km-values and the Vmax for phosphoserine and 2-oxoglutarate on the one side, and 4,5-dioxovalerate and glutamate on the other were found to differ by orders of magnitude
Fusiogenic Activity of Natural Amphiphiles, 5-n-Alkylresorcinols in a Yeast Protoplast System
Authors: Kozubek Arkadiusz , Skała Jacek 
Published: August 2018

Abstract
Two homologues of cereal grain resorcinolic lipids, 5-n-heptadecylresorcinol and 5-n-hepta-decenylresorcinol studied in the system employing yeast cell protoplasts showed marked fusiogenic activity. The frequency of hybrid formation induced by studied amphiphiles was significantly higher than that obtained with the use of 40% (w/v) polyethylene glycol 4000. The resorcinolic lipids as fusion-inducing agents did no affect regeneration of the cellular wall. The fusiogenic activity of resorcinolic lipids lost when calcium ions were absent in the medium. Fusiogenic activity of studied amphiphiles is related to their ability to induce non­ bilayer structures within the cellular membranes.
Identification of Amino Acids in Brazilian Propolis
Authors: Marcucci M. C. , Camargo F. A. de , Lopes C. M. A. 
Published: August 2018

Abstract
Amino acids of propolis samples from different origins were analysed and quantified. Seven of them presented almost the same percentage in all samples, indicating that bees may have obtained amino acids from three sources: plants, pollen contamination and from their own metabolism. The regeneration properties of propolis in relation to the presence of some amino acids are discussed.
Quantitative Changes of the Lipid and Fatty Acid Composition of Leaves of Aleurites montana as a Consequence of Growth under 700 ppm CO2 in the Atmosphere
Authors: He P , Radunz A , Bader K. P , Schmid G. H 
Published: August 2018

Abstract
Leaf lipids of Aleurites plants that were cultivated for 5 months in air containing 700 ppm CO2, were compared to those of control plants cultivated at 350 ppm CO2. The content of ether soluble lipids referred to dry matter is the same in CO2-and control plants. The comparison of lipids analyzed as the pigments chlorophyll and carotenoids, phospholipids and glycolipids shows that the ratio of phospholipids and glycolipids is slightly shifted in favor of phospholipids in CO2-plants. Thus, within the group of phospholipids, phosphatidylglycerol and phosphatidylinositol occur in higher concentrations in CO2-plants.
Although the differences in the lipid content appear moderate in CO2-and control plants, it is the saturation degree of fatty acids that differs substantially. The fatty acids of CO2-plants contain according to the higher phospholipid content approx. 5% more saturated fatty acids. Stearic acid is three-fold increased. Whereas in the phospholipid fraction saturated fatty acids comprise one half of all fatty acids, the unsaturated fatty acids make up for 80 to 90% in the glycolipid fraction. In CO2-plants not only in the phospholipid fraction but also in the glycolipid fraction saturated fatty acids occur in a higher portion. This means that not only in the cell membrane of CO2-plants but also in the thylakoid membrane the fluidity is decreased. Also in the wax-fraction long-chained carbonic acids with 20 -26 carbon atoms occur. As the portion of these carbonic acids is twice as high in CO2-plants, it is concluded that a stronger formation of the wax layers exists in CO2-plants.
By means of Western blotting and by the use of lipid and carotenoid antisera the binding of lipids onto proteins of photosystem II and photosystem I was analyzed. It is seen that besides the major amount of lipids which build up the thylakoid membrane, some lipids are also bound to membrane peptides. Whereas monogalactolipid is bound to the LHCP-complex peptides, to the OEC1 -peptide and the 43 and 47 kDa chlorophyll binding peptides, the anionic lipids sulfoquinovosyldiglyceride and phosphatidylglycerol and digalactolipid are bound to the core peptides of PS II and PS I. β-carotene and the xanthophylls were found to be bound to the core peptides and β-carotene and violaxanthin were also bound to the light-harvesting pigment complex.
Conjugative Transfer and Expression of Genes Coding for Periplasmic Nitrate Reductase in the Purple Bacterium Rhodospirillum rubrum
Authors: Klemme Jobst-Heinrich , Kaminski Annette , Hougardy Angela 
Published: August 2018

Abstract
Plasmid pFR400, a derivative of the vector plasmid pPHU231 containing the structural genes of the periplasmic nitrate reductase (nap genes) of Rhodobacter sphaeroides DSM 158 (F. Reyes et al., Molec. Microbiol. 19, 1307-1318 [1996]) was transferred by conjugative mating to a streptomycin-resistant strain of the nitrate reductase-negative nonsulfur purple bacterium Rhodospirillum rubrum S1. Transconjugant cells of the latter bacterium, identified by their resistance to streptomycin and tetracycline and by their plasmid pattern, contained an active nitrate reductase which, like other periplasmic bacterial nitrate reductases, was not repressed by ammonium.
Trehalose Protects Yeast Pyrophosphatase against Structural and Functional Damage Induced by Guanidinium Chloride
Authors: Sola-Penna Mauro , Meyer-Fernandes José Roberto 
Published: August 2018

Abstract
Trehalose is accumulated at very high concentrations in yeasts when this organism is sub­ mitted to a stress condition. This report approaches the question on the protective effect of trehalose and its degradation product, glucose, against structural and functional damage promoted by guanidinium on yeast cytosolic pyrophosphatase. Here it is shown that both, 1 ᴍ trehalose or 2 ᴍ glucose, are able to attenuate at almost the same extent the conforma­ tional changes promoted by guanidinium chloride on the pyrophosphatase structure. On the other hand, while 1 m trehalose increases 3.8 times the Ki (from 0.15 to 0.57 ᴍ) for guanidi­ nium chloride inhibition of pyrophosphatase activity, 2 m glucose did not even duplicate this parameter (from 0.15 to 0.25 ᴍ). These data support evidences for a functional reason for the accumulation by yeasts of trehalose, and not other compound, during stress conditions.
Indoid Glucosides from Four Balkan Endemics of the Galium incurvum Group (Rubiaceae)
Authors: Mitova Maja Iv. , Handjieva Nedjalka V. , Anchev Mincho E. , Popov Simeon S. 
Published: August 2018

Abstract
The Balkan endemics G. mirum, Galium macedonicum, G. rhodopeum and G. aegeum, from the G. incurvum group, were screened for iridoid glucosides. Eleven known iridoid glucosides were isolated, identified and analysed for the first time in the investigated plants.
The main components appeared to be asperuloside and/or the non-acetylated iridoid acids -deacetylasperulosidic acid, scandoside, monotropein. Phylogenetic relationships are discussed.
Quinolizidine Alkaloid Profiles of Retama raetam, R. sphaerocarpa and R. monosperma
Authors: El-Shazly A. , Ateya A.-M. , Witte L. , Wink M. 
Published: August 2018

Abstract
About 28 quinolizidine alkaloids and the dipiperidine alkaloids am modendrine, dehydroammodendrine and N -formylammodendrine were identified in the alkaloidal extracts of Retama raetam, Retama sphaerocarpa and Retama monosperma by capillary GLC and GLCMS. Alkaloid profiles of the three Retama species with a Mediterranean distribution are more similar than alkaloid patterns of different organs of the same plant. Whereas sparteine and retamine are the major components of stems, lupanine, retam ine, N-methylcytisine and cytisine dominate in flowers and pods, and cytisine in seeds indicating a high degree of organ specificity of alkaloid storage.