bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trennung von löslichen Plasma-Proteinen der Erbsenwurzel durch Acrylamid-Scheibenelektrophorese
Authors: Polter Conrad 
Published: February 2015

The method of STEWARD, LYNDON, and BARBER (1965) has been used, with some modifications, for the electrophoretic separation in acrylamide gel columns of soluble proteins from different root sections of pea seedlings. The influence of several experimental variables on the effectiveness of separation was studied. The results deviate from results already in the literature.
Different catalyzers for gel polymerisation (β-dimethyl amino-propionitrile, N,N,N′,N′-tetramethylethylenediamine) have a small but detectable influence upon the separation. Fresh staining solutions (amido black 10 b) improve separations compared with repeatedly used ones, probably due to faster protein denaturation. Destaining of columns in the direction of protein movement renders better results than destaining in the opposite direction, since during destaining the protein bands shift slightly in the direction of destaining. Comparison of columns of the same proteins destained in each direction is useful.
Dialysis against Tris-glycine-buffer (pH 8.3) prior to separation diminished the number of protein bands, to different extents depending upon the developmental stage of the root sections. The protein bands of older root segments changed the least. Protein solutions dialyzed against double distilled water and returned to buffer showed fewer bands which was probably the result of denaturation. Different storage times for frozen protein solutions (-20 °C) as well as conditions during polymerisation of the acrylamide gel had effects on protein separation. In all cases proteins from older segments were more stable than those from younger segments.
Comparison of our results with the literature shows that the quality of protein separation by disc electrophoresis in acrylamide is critically dependent upon methods of isolation and concentration of protein solutions. The upper limit of efficiency of the method seems to be about 30 protein bands at present.
Untersuchungen über die Kinetik der Spaltung von Di- und Tripeptiden
Authors: Hartmann Hermann , Brüssau Rudolf 
Published: February 2015

Gegenstand der vorliegenden Untersuchung ist das hydrolytische Verhalten von Glycyl-seryl-alanin beim Erhitzen in einer rein wäßrigen Lösung bei einem pH-Wert in der Nähe des isoelektrischen Punktes. Die Reaktionsmöglichkeiten des Tripeptids und aller Folgeprodukte, die Alanin enthalten, wurden qualitativ aufgeklärt und die kinetischen Daten der einzelnen Reaktionen durch quantitative Hydrolyseversuche an den mit dem Kohlenstoffisotop 14C geeignet radioaktiv markierten Verbindungen Glycyl-seryl-alanin, Seryl-alanin, Alanyl-serin und Seryl-alanyl-diketopiperazin bei mehreren Temperaturen zwischen 55 und 95 °C bestimmt. Die Trennung der Hydrolysatproben erfolgte mit Hilfe der Papierchromatographie bzw. der Papierelektrophorese; für die Konzentrationsbestimmung der radioaktiven Substanzen wurde ein Verfahren ausgearbeitet, das eine Radioaktivitätsmessung mit hoher reproduzierbarer Ausbeute direkt auf den zur Trennung benutzten Filterpapieren nach der Flüssigkeitsszintillations-Methode ermöglicht.
Alle beobachteten Reaktionen verlaufen unter den Versuchsbedingungen nach einem Zeitgesetz 1. Ordnung. Die Konzentrations-Zeit-Funktionen der einzelnen Reaktionsteilnehmer wurden durch Auflösung der simultanen linearen Differentialgleichungen 1. Ordnung bestimmt und zur Berechnung der Reaktionsgeschwindigkeits-Konstanten nach einem iterativen Ausgleichsverfahren herangezogen.
In der Diskussion wird versucht, die beobachteten thermodynamischen Daten in ihrer Größenordnung aus anderen Eigenschaften und aus der Molekularstruktur der einzelnen Verbindungen abzuleiten und durch bestimmte Reaktionsmechanismen zu interpretieren.
Isolierung von Riboflavin-Mangelmutanten von Saccharomyces cerevisiae
Authors: Oltmanns O. , Lingens F. 
Published: February 2015

Riboflavin-deficient mutants of S. cerevisiae, not known hitherto, were isolated using a yeast extract-peptone-dextrose medium supplemented with 10 γ riboflavin/ml. After treatment with ethylmethanesulfonate, 0,4% of the surviving cells or 2% of the isolated biochemical mutants were deficient of riboflavin.
Seven of 14 riboflavin deficient mutants were tested for temperature dependence but no such dependence was found. Two mutants accumulated a green fluorescing substance. Cross-feeding tests were not successful.
Reaktionen von OrganometallVerbindungen II
Authors: Huber F. , Horn H. , Haupt H. J. 
Published: February 2015

Die Acidolyse von Tetraorganoplumbanen PbR4 mit verschiedenen aciden Verbindungen HX (z. B. CH3COOH, CF3COOH, CCl3COOH, C (CH3)3COOH) wurde hinsichtlich des Einflusses der Reste R und der Acidität von HX auf die präparative Anwendbarkeit dieser Reaktion zur Darstellung von R3PbX und/bzw. R2PbX2 untersucht.
Tetraphenylplumban reagierte in allen Fällen deutlich schneller mit HX als Tetraalkylplumbane.
Mit Trifluoressigsäure ließen sich (alkyl) 3PbX, (alkyl) 2PbX2 und (C8H5) 2PbX2, nicht jedoch (C6H5) 3PbX gewinnen.
Trimethylessigsäure reagiert mit Pb (alkyl) 4 so langsam, daß Zersetzungsreaktionen überwogen und die Darstellung von hydrolysierbarem (!) (C2H5)2PbX2 nur unter SiO2-Katalyse gelang.
Pb (II) -Verbindungen entstanden in mehr oder weniger großer Menge besonders dann, wenn bei der Acidolyse Carbonsäuren bzw. deren Derivate oder HS-acide Verbindungen (C6H5SH, HOCH2CH2SH) eingesetzt wurden.
Nucleinsäure-Stoffwechsel der Rattenleber während der Carcinogenese mit N-Nitroso-morpholin
Authors: Kröger Hans , Lucking Theodor 
Published: February 2015

Während der Verfütterung von N-Nitroso-morpholin wurde der Nucleinsäure-Stoffwechsel in der Rattenleber studiert.
1. Schon kurze Zeit nach Beginn der Verabreichung von NM ist der Einbau von 14C-Orotsäure und 32P-Orthophosphat in die Kern-RNS der Leberzellen erhöht.
2. Das Basen-Verhältnis der RNS aus präcanzeröser Leber unterscheidet sich nur unwesentlich von dem der RNS aus normaler Leber.
3. Die Matrizen-Funktion der DNS, die zu verschiedenen Zeiten während der Carcinogenese aus der Leber isoliert wurde, erweist sich im RNS-Polymerase-System als unverändert.
Analysis of an Experimental Model of DNA Unwinding
Authors: Tohá J. , Edwards J. , Aguilera A. , Colombara E. 
Published: February 2015

Experiments are described, showing that DNA solutions with lithium chloride present a hypochromicity, which increases with the molarity of the salt. Different absorbancy versus temperature curves are obtained for different solutions, and it is found that the melting point (Tm) increases with the lithium chloride concentration. When cooling the samples, the absorbancy decreases in a symmetric way.
In accordance with this model, a theory of DNA unwinding is proposed, assuming that before the unwinding, it is necessary a stretching of the molecule which eases this process. An extension of these ideas are applied, to the transcription DNA-RNA operation.
Aggregationsstufen und Biosyntheseleistungen von Rattenleber-Ribosomen unter dem Einfluß Ribosomen-spezifischer Antikörper
Authors: Meyer-Bertenrath Jürgen G. , Würz Hannelore 
Published: February 2015

The formation of antibodies against rat liver ribosomes was induced by intravenous injections of ribosomal preparations into sheep and rabbits. These preparations did not contain any cytoplasmic proteins detectable by immunoelectrophoresis.
The existence of specific antibodies was demonstrated by precipitation, haemagglutination and complement fixation.
During incubation of ribosomes with antiserum an aggregation of the ribosomes takes place. Obviously, the formation of dimeric aggregates is a direct antigen-antibody-reaction, which, in a secondary process, may be followed by formation af heavier aggregates, containing at least six ribosomes.
These complexes are no longer active in synthetizing proteins in vitro. It may be concluded, therefore, that on the surface of the ribosome the site of antibody fixation is located closely to the protein binding site and the transfer-RNA binding site, respectively.
Selektiver Verbrauch von gesättigten Fettsäuren während der Metamorphose von Weibchen und Arbeiterinnen der Ameise Formica polyctena Foerst. (Hymenoptera: Formicidae)
Authors: Schmidt Gerhard H. , Mathur Avinash C. 
Published: February 2015

The changes in the contents of saturated fatty acids during metamorphosis of female ants and worker ants of the species F. polyctena have been studied paper chromatographically. Myristic, palmitic, stearic, and arachic acids are present, palmitic acid being found in the highest concentration. Myristic and arachic acid comprise less than 5% of the saturated fatty aids in almost all metamorphic stages. Behenic acid has been found in females shortly before the hatching of the adult.
The contents of all saturated fatty acids decline during metamorphosis until emergence of the adult. Palmitic acid shows the greatest relative decrease, whereas stearic acid shows a relative increase.
In the female prepupal stage the content of saturated fatty acids is relatively lower than in the corresponding worker one. Before emergence of the adult the proportions are reverse. During the metamorphosis therefore the workers consume relatively more saturated fatty acids than the females.
The proportions of the saturated fatty acids are similar in the prepupae of the females and workers. During the metamorphosis the content of palmitic acid falls down stronger in females than in workers. The highest decrease is combined with a marked fat reduction. The found differences between the two casts are discussed together with earlier results of their different fat metabolism.
Beiträge zur 31P-KMR-Spektroskopie II
Authors: Latscha Hans Peter 
Published: February 2015

Chemische Verschiebungen von Phosphorkernen in Verbindungen mit Phosphor der Koordinationszahl 5 und 6 sowie in zahlreichen Phosphor-Stickstoff-Ringverbindungen sind tabellarisch zusammengestellt und werden z. T. diskutiert.
In zwei Fällen wird eine 31P-1H-Kopplung über drei Bindungen hinweg berichtet.
Zur Plastochinonreduktion bei der Photosynthese
Authors: Schmidt-Mende P. , Rumberg B. 
Published: February 2015

The absorption changes at 254 nm which are coupled with the formation of plastohydroquinone (PQ=) depend strongly on the intensity and duration of the actinic light (fig. 2). At an intensity of 106 erg·sec-1·cm-2 and a duration of 0,1 sec, maximal reduction is obtained. The reduction of chlorophyll-ai ° was followed by absorption changes at 703 nm. From the changes at 254 and 703 nm (fig. 3 and tab. 1) follows: PQ=: Chl-aI = 5:1 (with Δε = 1,3·104l · Mol-1· cm-1 for PQ at 254 nm and Δε = 3,6 · 104 l · Mol-1 · cm-1 for Chl-aI at 703 nm). This value corresponds to a pool of plastoquinone with a dynamic capacity of ten electrons. This value is exactly the same as that which was derived in another way in the preceding paper 3.
The time course of the reduction of plastoquinone is given by an exponential function (figs. 4 and 5) with a rate constant for the reduction k1′= 35 sec-1 at 25 °C. Together with the rate constant for the reoxidation (k2′ = 11 sec-1, see next paser 6), it follows for the total photochemically engaged plastoquinone PQ0: Chl-aI = 6.5: 1.
Quantitative Zusammenhänge zwischen Chlorophyll-b-Reaktion, Elektronentransport und Phosphorylierung bei der Photosynthese
Authors: Rumberg B. , Siggel U. 
Published: February 2015

Carefully prepared spinach chloroplasts show the slow phase (half life 20 — 500 msec) of the absorption changes of Chlorophyll-b only. The decay of the absorption changes is an exponential one (fig. 1, fig. 5, eq. 1). The decay time as well as the electron transport rate are changed by coupling and uncoupling phosphorylation.
A. By addition of the phosphorylation uncoupler methylamine hydrochloride the decay is accelerated up to ten times from 500 msec to 50 msec at pH = 7,4 and 20 °C (fig. 1, table 1). At the same time the electron transport rate measured by the reduction of ferricyanide increases ten times (table 1). Reciprocal decay time and electron transport rate are always proportional to each other (fig. 2, eq. 2).
Phosphorylation uncouplers as carbonyl cyanide phenylhydrazone, atebrin, and dichlorphenol indophenol accelerate the decay of the Chl-b absorption changes as well (fig. 3).
B. Phosphorylation accelerates the decay time of the Chl-b absorption changes up to two times from 90 to 40 msec at pH=8,4 and 20 °C (fig. 4, fig. 5, table 2). At the same time the electron transport rate too increases two times, thus reciprocal decay time and electron transport rate are proportional to each other again (fig. 6, table 2). The same result is obtained when phosphorylation is suppressed by omission of phosphate or addition of phlorizin (fig. 6, fig. 7 top). It is shown that the phosphorylation rate is identical with the extra electron transport rate stimulated by phosphorylation as measured by IZAWA et al. 18 (fig. 7 bottom). At the same time it is shown that phosphorylation is proportional to the change in the reciprocal decay time of the Chl-b absorption changes (fig. 7 bottom, eq. 3).
JUNGE and WITT 3 show that the slow phase of the Chl-b absorption changes are connected with the translocation of protons across the thylakoid membrane. In connection with those results phosphorylation is coupled to an additional proton transfer. The foregoing results are discussed in this respect in 1. c. 3.
The results are in part reviewed in *.
Die Hemmung photosynthetischer Reaktionen durch Herbicide des Biscarbamat-Typs
Authors: Trebst A. , Pistorius E. , Boroschewski G. , Schulz H. 
Published: February 2015

3-Alkoxycarbonylaminophenyl-N-aryl- (alkyl-) carbamates, abbreviated as biscarbamates here, are potent inhibitors of photosynthetic electron transport in isolated spinach chloroplasts. By testing 50 compounds the structural requirements for maximal inhibitory activity were determined. To obtain inhibition of photosynthesis by a biscarbamate at a concentration of 10-7 Mol/l the two carbamate side chains of the biscarbamate must be in meta position on the central phenylring.
N-Methylation and C-methylation in ortho position to the acidic NH groups of the carbamate side chains reduces the inhibitory activity. The biscarbamates are specific inhibitors of light reaction II of photosynthesis, since they do not inhibit cyclic photophosphorylation and photosynthetic NADP reduction at the expense of an artificial electron donor system.
2. Über die Hämolyseaktivität von Lysolecithin, das durch Lecithinspaltung mit Phospholipase A in wäßrigem Milieu erhalten wird
Authors: Hölzl J. , Wagner H. 
Published: February 2015

Die hypothetische Zwischenverbindung, die bei der Phosphatidylcholin (PC)-Spaltung durch Phospholipase A (E.C. 3.1.1.4.) aus Crotalus terr. terr. und durch Crotalus adamant.-Schlangen-Gift in wäßrigem System entsteht, entfaltet gegenüber Rindererythrocyten im Gegensatz zu freiem Lysophosphatidylcholin (LPC) nur eine sehr geringe Hämolyseaktivität. Dieses Ergebnis ist eine weitere Bestätigung für die Bildung einer Zwischenverbindung bei Einwirkung von Crotalus-Phospholipase A auf PC in wäßrigem Medium. Zusatz von Desoxycholat setzt das „gebundene Lysolecithin“
in Freiheit und führt zu der erwarteten Totalhämolyse. Lysolecithin, das man nach Bienengifteinwirkung im wäßrigen Medium erhält, entspricht in seiner lytischen Wirkung dem „freien“ Lysolecithin.
IV. Acid denaturation of polyadenylic-polyuridylic complexes
Authors: Clauwaert J. 
Published: February 2015

Interactions between A and U and between A and A were studied by spectrophotometric titrations in the acid pH branch. Titrations of the 1 A—1 U solutions have shown that, at higher ionic strengths (ω&gt;0.1), there occurs first a conformational transition of the (A+U) form to the (A+U+U) form in the pH range 5.2 to 3.8: only at lower pH one has the dissociation of (A+ U + U) to the components. A phase diagram, showing the stability conditions of the different A —U structures as a function of ionic strength and pH was drawn.
By comparing the alkaline and acid dissociations of 1 A—1 U and 1 A —2 U solutions, the pK values of A can be determined: several expressions for this determination can be proposed depending on the extent to which the cooperative dissociation of (A+U) is influenced by the cooperative formation of (A+A) from A. The results suggest that, in contrast to U, the polyelectrolyte character of the polynucleotide, originating from the phosphate backbone, cannot account for the pK shift of the adenine residue of A. A knowledge of the dissociation constant of the adenine residue is useful in calculating the interaction energy of (A+A). A undergoes a-sharp conformational change on titration with acid in the pH range 6.1 to 5.6, which has been interpreted as a A—A interaction with formation of a (A+A) helical structure. By comparing the transition pH of (A+A) with the dissociation constant of the adenine residue, it is possible to calculate the free energy change of (A+A) formation by use of the relation ΔF= — 2,3 R T Δp K. A qualitative comparison of the determined ΔF values with the calorimetric enthalpy changes suggests that A—A interactions are characterised by small entropy changes.
Zur Kenntnis der Quellung von Kollagen in Alkanolen
Authors: Nemetschek Th. 
Published: February 2015

The swelling of collagen in alcanols is described.
The n-alcanolmolecules are deposited between the protofibrillayers in orderly fashion. The changes of the equatorial reflexes indicate a strong relation between the spaces of protofibrils and the length of alcanol-chains.
The equatorial spacings can be distinguished over the limit of 15 A, measured in swelling by water.
Flash Photolysis of Thiopyronine
Authors: Morita Masaharu , Kato Shunji 
Published: February 2015

Flash photolytic investigation of photosensitizing dye “thiopyronine” was undertaken with and without redox substrates.
Flash excitation of thiopyronine deaerated buffered solution without any substrate produced three transient intermediates; triplet state (Dt), half-oxidized form (Oxd) and half-reduced form or semiquinone (Red) of the dye. Red and Oxd were generated through the electron transfer reactions, Dt - Dt and Dt-D (D is a dye molecule in the ground state).
Absorption spectra of these intermediates were identified and their reaction mechanisms were established.
The high efficiency of this dye in the photodynamic effect was discussed in connection with the high quantum yield of triplet state production and photochemical redox reversibility of the dye.
Primary Inducible Fluorescence in Secretory Granules of Tumor Cells Supravitally Stained by a Toluidine Blue Dye
Authors: Bastos A. L. , Marques Dante V. , Da Silva J. Filipe , Nunes J. B. Moura , Correia A. Dias , Vigário J. D. , Terrinha A. M. 
Published: February 2015

In a toluidine blue dye (British Drug Houses, batch no. 651880), we report a purple chromatographic fraction (Rf-0,55) with a spectral absorption peak at 622 mμ, which has the property to induce immediate bright yellow fluorescence (primary inducible fluorescence) in cytoplasmic granules of tumor cells. The cells are unfixed, supravital stained and examined by fluorescence microscopy. The mean number of fluorescent granules per tumor cell was 36, ranging from 19 to 64 (50 cells).
The effect of ultraviolet illumination on cells with fluorescent reaction is described, with reference to the shift of colour emission in the cytoplasmic bodies. These granules are Sudan Black and Oil Red positive, and become black after fixed cells are treated by osmium tetroxid. Actively growing cells accumulate basic dyes in lysosomes, and on this evidence, we base our belief that the granules of tumor cells with positive fluorescent reaction to this toluidine blue contain lipids, probably unsaturated fatty acids, are of secretory nature and might be derived from primary lysosomes.
4. Mitt.: Über den Einfluß von Äthioniamid auf den endogenen Stoffwechsel von Myc. smegm.
Authors: Reutgen H. , Iwainsky H. 
Published: February 2015

Die Wirkungsweise von Äthioniamid auf Myc. smegm. wird mit Hilfe von 32P unter Bedingungen der endogenen Atmung untersucht.
Folgende methodische Veränderungen erweisen sich als vorteilhaft: Auflösung des Gesamtablaufes in einzelne, zeitlich stark verkürzte Markierungsphasen, Erfassung der Polyphosphatfraktion, simultan durchgeführte Ionenaustauschchromatographie der säurelöslichen Fraktion.
Als erste erfaßbare Wirkung des Äthioniamides ergibt sich eine Stimulierung des 32P-Einbaues in die säurelösliche Fraktion.
Gleichzeitig ist eine Hemmung des 32P-Überganges in die Polyphosphat- und in die RNS-Fraktion festzustellen.
In die Lipide und in die DNS-Fraktion werden unter den Versuchsbedingungen nur geringe Mengen eingebaut. Ein deutlicher Einfluß des Äthioniamides ist nicht zu erkennen.
Wird der Gesamt-32P-Einbau berücksichtigt, dann bewirkt Äthioniamid eine Blockierung des sonst erfolgenden 32P-Einbaues in die Polyphosphat-Fraktion.
Neben anderen Veränderungen wird bei der Ionenaustauschchromatographie der säurelöslichen Fraktion eine erniedrigte AMP- und eine erhöhte ADP- bzw. ATP-Konzentration festgestellt. Als primärer Angriffspunkt wird daher eine Störung des ATP-Stoffwechsels diskutiert.
Enzymhistochemische Untersuchungen der Adenosin-Triphosphatase, der alkalischen und sauren Phosphatase sowie der Succinodehydrogenase im Leberparenchym der Ratte während der Einwirkung des Cancerogens Diäthylnitrosamin
Authors: Borner P. , Gössner W. 
Published: February 2015

Der Einfluß von Diäthylnitrosamin in cancerogenen Dosen auf die Adenosin-Triphosphatase. alkalische und saure Phosphatase sowie die Succinodehydrogenase der Rattenleberzelle wird mit enzymhistochemischen Methoden untersucht. Diese Enzyme wurden ausgewählt, da sie an charakteristische Strukturen der Leberzelle gebunden sind.
DANA führt zu folgenden enzymhistochemischen Veränderungen im Leberparenchym: Schwund der ATPase aus umschriebenen Bereichen des Parenchyms. Aufhebung der peribiliären Anordnung der durch ihren Gehalt an saurer Phosphatase dargestellten Lysosomen. Diffuse Verteilung der Lysosomen im Cytoplasma der Leberzelle. In späteren Phasen der Cancerogenese wird die peribiliäre Anordnung der Lysosomen teilweise wiederhergestellt. Allmähliche Herabsetzung der Aktivität des Mitochondrienenzymes Succinodehydrogenase in ausgedehnten Parenchymbezirken. Auftreten von alkalischer Phosphatase in der Wand einzelner Leberzellen in späten Phasen der Cancerogenese.
Die Bereiche des Leberparenchyms, in denen es zum Schwund der ATPase der Gallenkapillaren und zu Veränderungen in der Anordnung der Lysosomen kommt, weisen jeweils auch einen Verlust der Glucose-6-Phosphatase auf.