Volume 23, Issue 1

The mass spectra of the metal carbonyls of Ni, Fe, Cr, Mo and W have been established. The ionization potentials and the energy necessary to form the various fragment ions have been measured. These data are used to calculate heats of formation for the various ions. The following dissociation energies were also calculated from the appearance potential data and ancillary thermochemical data and the valence state excitation energies: 1) specific bond dissociation energies for singly charged metal carbonyl ions, 2) average dissociation energies for singly charged parent ions, 3) average dissociation energies of neutral metal carbonyls to ground state products in which case comparison to calorimetric measurements are given, and 4) average dissociation energies of the metal carbonyls to valence state excited products. The unimolecular decomposition of metal carbonyls is discussed and the appearance potentials of the metal ions are used to calculate valence state excitation energies for the metal atoms. These values, W* = 3.18 eV, Mo* =4.92 eV, Cr* = 8.04 eV or 7.41 eV and Fe* = 6.57 eV are in excellent agreement with the observed spectroscopic values for Mo and with the values calculated from spectroscopic measurements of Cr and Fe. The value for the valence state excitation energy of W is the first reported in the literature.

32 P-labeled derivatives of Dimethoate (n, iso, and tert.-butylamide) and O,O-dimethyl-thio-and-dithiophosphoryl acetic acids were prepared and their hydrolysis at 25° and 40 °C from p H 2 to 10 was measured. Constants and half times are listed. From the results conclusions relating to the mechanism of hydrolysis are deduced.

Querschnitte durch röhrenförmig zusammengesetzte Schraubenmodelle lassen die Einzelschrauben als „Untereinheiten“ erkennen. Bei senkrechter Schnittführung erscheinen diese untereinander gleich und symmetrisch in der Röhrenwand angeordnet (Abbn. 1-6). Bei schräger Schnittführung sind sie scheinbar ungleich und unsymmetrisch verteilt (Abbn. 1 A-6 A). Unvollständig geschlossene Röhren wie das Modell links in Abb. 5, können nur entsprechende Sektoren der beschriebenen Schnitte zeigen. Die Struktur dieser Modelle erklärt den Bau verschiedener elektronenmikroskopisch aufgefundener „Mikroröhrchen“ und „Röhrchen“ des Protoplasmas (vgl. Abbn. 7 - 15). Erscheinungen, wie sie bei der schnellen Rotation der Schrauben in Flüssigkeiten auftreten, wer den an Hand von Modellversuchen beschrieben und liefern Erklärungsmöglichkeiten für die Selbstanordnung röhrenförmiger Proteinteilchen, für die Lage der um „Mikroröhrchen“ ausgebildeten Membranen, für die an Plasmaoberflächen nachweisbaren Pulsationen, für den aktiven Stofftransport z. B. der „Microvilli“ und für die zwischen Proteinfibrillen vorkommenden „Querbrücken“. Es ergeben sich Grundlagen für eine Theorie der „aktiven Enzymzentren“, die als Schwingungsknoten der rotierenden Schrauben aufgefaßt werden.

The pK' values of the current bases, nucleosides, nucleotides, nucleotide derivatives and poly U have been determined over a large range of ionic strength. The pK' shifts of the monomers due to variations in ionic strength can be accounted for qualitatively and quantitatively by means of the relation The collision diameters of uracil, uridine, uridine cyclic -2':3'-phosphate and 3' (2') -uridylic acid were determined. The introduction of phosphate affects the charge, resulting into differences in activity coefficient between nucleotides and their corresponding nucleosides and bases. A substitution of -H by ribose at N (3) of uracil or cytosine or at N( 9 ) of adenine or guanine results into an electron withdrawal from the bases with lowering of the pK' value. 2'-Deoxyribose exhibits a weaker electron attraction. Introducing -CH 3 at C(5) of uracil yields electrons to the base and the pK values of various thymine derivatives are about 0.5 p H units higher than those of the corresponding uracil derivatives. A phosphate group on C 2 or C 3 results in an electrostatic attraction of the dissociable proton, so that the pK' is increased at low ionic strengths; at higher ionic strengths screening off occurs and the pK' values of the nucleotides become almost the same as those of the corresponding nucleosides. The site of substitution on the ribose moiety is important: C 2' -O-phosphate seems to exert a stronger electrostatic attraction on - NH 3 ⊕ groups than C 3' -O-phosphate, whereas C 5' -O-phosphate exerts in addition an inductive effect that is dependent on the presence of - OH on C 2 . The electrostatic influence of the phosphate groups on the uracil moiety in UpU, UpC and CpUpC runs roughly parallel to that found in cyclic-2':3'-nucleotides. The pK' shifts experienced in poly U are related to the polyelectrolyte character of this polymer. A new treatment for the evaluation of the electrostatic potential of polynucleotides (poly U) is proposed that is based on the usual rodlike (polyelectrolyte) model.

During spectrophotometric titrations of uracil in different alkali- or alkali earth chlorides, specific changes in the U.V. absorption of uracil at p H 12.0 have been observed. The spectra of 4-methyl and 5-methyl uracil change in the same way whereas 1-methyl and 3-methyl uracil are not influenced even by strong divalent cations. From spectrophotometric and potentiometric titrations it could be concluded that the changes are not due to the dissociation of the groups. From the probable site of interaction it seems impossible that uridine or uridylic acid may be involved in such interactions. From optical density measurements the K s value has been determined.

Interactions between poly A and U been studied by spectrophotometric titrations. The dissociation constant of the groups in poly U having been determined at various ionic strengths, spectrophotometric titrations of solutions containing poly A and poly U in the ratio 1:1 and 1: 2 were performed in the alkaline p H range. By comparing the pK' of poly U with the transition p H of the (A+U) and (A+U+U) complexes, it was possible to calculate the free energy changes of the (A+U) and (A+U+U) helical structures. By doing so at various ionic strengths we were able to determine the electrostatic contribution to the free energy changes and to deduce the electrostatistic potential of the two and three stranded complexes. Titrations of the poly A-poly U aggregates have been performed at various temperatures and provided us with the free energy variation of these aggregations with temperature at various ionic strengths. From these results, it was possible to estimate enthalpy and entropy values of the formation of the (A+U) and (A+U+U) complexes. The energetic and thermodynamic relations of the conversion of the two- and the three stranded complex have been determined too.

Bei der Elektrolyse des geschmolzenen Komplexes KF-2·Be (C 2 H 5 ) 2 wird an der Kathode primär K ⊕ entladen, welches dann in einer Zementierungsreaktion Beryllium ausfällt. Der Elektrodenbelag enthält kristallines Beryllium und Be 2 C sowie polykristallines Kalium. Die Netzebenenabstände des elektrolytisch erzeugten Berylliums sind doppelt so groß wie die der normalen α-Modifikation. An inerten Anoden wird das Radikal C 2 H 5 · abgeschieden, welches zu C 2 H 4 und C 2 H 6 disproper tioniert. Bei Verwendung einer Berylliumanode wird an der Anode quantitativ Be (C 2 H 5 ) 2 gebildet.

Δ 7 -Stigmastenon-(3) and Δ 7 -stigmastenol-(3β) have been isolated from Coccinia indica. Cucumis sativus, C. melo, Cucurbita pepo and Citrullus vulgaris contain sterols IV, V and VI.

Die Pygidialwehrblasen von Idiochroma dorsalis enthalten als Wehrstoffe Salicylsäuremethylester und Ameisensäure. Als Hauptkomponente wurde gaschromatographisch, IR- und massenspektroskopisch n-Undecan neben n-Decan nachgewiesen.

Total RNA from yeast stimulates the incorporation of 14 C-amino acids into material insoluble in hot trichloroacetic acid in a cell-free E. coli system. In a sucrose gradient the stimulating RNA fraction sediments together with the 28 S fraction of ribosomal RNA. RNA from isolated yeast ribosomes preincubated with RNase was active in amino acid incorporation as well. Preincubation of ribosomal RNA at 70° resulted in an increased incorporation activity of the RNA. However, attempts to separate an active messenger fraction from total RNA as well as from 28 S RNA by heating were unsuccessful. The presented data indicate that ribosomal RNA itself is active in cell-free amino acid incorporation. By hydrolysis of the incorporation products it could be shown that the 14 C-amino acids used in the cell free system were incorporated into peptides. The bulk of the radioactive peptides had a molecular weight below 2000 as estimated by Sephadex gel filtration.

On the irreversible conversion of glucose-6-phosphate to fructose-6-phosphate in H 2 O/HOT with glucose-6-phosphate-isomerase 8 - 10% of the tritium content per gram atom hydrogen in the water are incorporated. The corresponding figures for the enzymatical conversions of mannose-6-phosphate → fructose-6-phosphate, dihydroxyacetone phosphate → glyceraldehyde phosphate, phosphoenol pyruvate → pyruvate are 17 - 18, 15 and 16% respectively. When fructose-l,6-diphosphate is transferred into dihydroxyacetone phosphate 40-45% tritium is fixed and 40% when pyruvate is decarboxylated to acetaldehyde. The triose isomerase reaction is approximately 10% intramolecular.

Baker’s yeast was incubated anaerobically and aerobically in H 2 O/HOT with uniformly labeled 14 C-glucose. After partial fermentation the tritium distribution in some intermediates was determined. The equilibriums glucose-6-phosphate ⇄ frucose 6-phosphate ⇄ mannose-6-phosphate has not been reached. The tritium distribution in mannose-6-phosphate markedly differs from that in glucose- and fructose-6-phosphate. In fructose-1,6-diphosphate C-3, 4 and 5 have obtained the highest tritium label possible. The tritium content in the methyl group of ethanol is in good agreement with that obtained by adding up the tritium incorporation of every single step determined experimentally.

1. 3 H-Thymidin und 3 H-Cytidin werden sehr rasch in die DNS bzw. RNS der Rattenmilz eingebaut. 2. Während der Erstimmunisierung mit Brucella abortus ist der Nucleinsäure-Stoffwechsel in der Rattenmilz gesteigert; die DNS-Synthese nimmt wesentlich mehr zu als die der RNS. 3. Die Basen-Zusammensetzung der Kern-RNS wird durch Immunisierung leicht verändert. 4. Während der Zweitimmunisierung mit Brucella abortus ist der Nucleinsäure-Stoffwechsel in der Rattenmilz ebenfalls gesteigert; die RNS-Synthese erreicht das Maximum schneller, die DNS-Synthese langsamer als bei der Erstimmunisierung.

1. Endoxan hemmt, insbesondere während der Erstimmunisierung, die Ausbildung von Antikörpern gegen Brucella abortus; 6-Mercaptopurin hat einen weitaus geringeren Effekt. 2. Beide Substanzen vermindern die DNS-Synthese in der Rattenmilz erheblich, die der RNS hingegen nur wenig. 3. Die Induktion der Tyrosin-α-Ketoglutarat-Transaminase in der Rattenleber wird durch Endoxan nicht gestört. 4. Diese Ergebnisse lassen den Schluß zu, daß bei der Erstimmunisierung zur Ausbildung der Antikörper eine DNS-Synthese unerläßlich ist.

Die auf der Zelloberfläche lokalisierte, dereprimierbare saure Hefephosphatase hat keinen Einfluß auf anaerobe Glykolyse und Wachstumsgeschwindigkeit. Bei Phosphatmangel kann sie der Hefezelle im Medium vorhandene Phosphatester als Phosphatquelle erschließen. Die saure Hefephosphatase ist nicht identisch mit der intrazellulär wirksamen Phosphatase.

Electron micrographs of thin sections of the mesophyll cells of red kidney bean leaves (Phaseolus vulgaris), which had in negatively stained “dipping method”-preparations been shown to be infected with a rod-shaped virus, revealed an unusual cytological feature. The cytoplasm of these cells contains pinwheel-like inclusions comparable to those recently described by several authors in various other plants after infection with viruses. In these particular inclusions, however, parallel bands, 7 nm broad and 7-10 nm high, with a spacing of 10 to 15 nm are found lying upon the convex side of the lamellar plates of the inclusion body. From longitudinal, transverse and tangential sections a three-dimensional model of these inclusions has been constructed.

ESR-spectra of purified preparations of bacteriophage and of DNA extracted from these objects were found to contain the characteristic lines of atomic hydrogen after γ-irradiation at 77 °K. The experimental results demonstrate the production of atomic hydrogen by irradiation of organic materials in a direct way. The high stability of the trapped hydrogen atoms is indicated by the fact that heating to 200 °K for 10 min reduces the spectral amplitudes by a factor of two only. The yield of trapped atomic hydrogen varied between 0.05 and 0.6 while the total radical yield derived from the ESR-spectra was found between 1.0 and 3.0. Addition of moisture to vacuumdried samples did not enhance the yield of H-atoms. At 50% water content the yield was also reduced to about 50% other parameters remaining unchanged. The disappearance of hydrogen lines on heating is accompanied by an enhancement of the octet spectrum due to the addition of atomic hydrogen to thymine groups. The observation of H-stabilization in inorganic phosphates is taken to suggest trapping by phosphate groups in DNA. The efficiency of trapping is probably influenced by the presence of impurities, notably transition metals. The apparent g-factor of 2.014 ± 0.002 is explained by IS-coupling. The true g-factor obtained by application of the Breit - Rabi formula is equal to the free electron value within experimental limits of error.

The distribution of antigen components of adenovirus type 26 in aqueous two-phase systems of sodium dextran sulfate and polyethylene glycol is described. Depending on composition and NaCl molarity of the system, the infectious particles and the soluble haemagglutinin were either concentrated in one phase or distributed in two phases and separated from one another. The complement-fixing group antigen could not be determined, since the polymers interfered extensively with the CF test.

5-Fluor-2′-desoxyuridin (FUdR) blockiert in tierischen Zellen und Bakterien fast ausschließlich die DNS-Synthese. Auch die Vermehrung von Viren, deren Genom aus DNS besteht, wird in derartigen Zellen selektiv gehemmt. Wir versuchten mit der meist verwendeten FUdR-Dosis von 1 μMol/l den cytopathischen Effekt von Vaccinia-Virus in „KB“-Zellfilmen (monolayer) zu unterdrücken. Dies gelang jedoch erst mit 50 μΜοl/l FUdR. Zur Klärung der diskutierten möglichen Ursachen dieses Versagens untersuchten wir mit 3 H-markiertem Thymidin ( 3 H-TdR) die Vorgänge bei der Vaccinia-Virus-Infektion und bei deren Hemmung. Die autoradiographische Auswertung ergab folgendes: Mit 1 μΜοl/l und mit 50 μΜοl/l behandelte Zellfilme wiesen weit mehr 3 H-TdR-markierte Zellkerne auf als unbehandelte Kontrollen, was als Synchronisationseffekt von FUdR angesehen wird. Die Unterdrückung der Zell-DNS-Synthese durch die Vaccinia-Virus-Infektion war deutlich zu beobachten, ebenso die Ausbildung der cytoplasmatischen Herde der Virus-DNS-Synthese. Bei Verwendung von 1 μΜο/l FUdR wurde ein verzögertes Ingangkommen der Virus-DNS-Synthese beobachtet. Anzeichen hierfür blieben bei 50 μΜοl/l aus.

The metabolic fate of C 14 -methanol and 1-C 14 -ethanol in the adult larva of Prodenia litura has been investigated in vivo. Following the intersegmental injection of C 14 -methanol (1.2 mg/g. insect), about 70% of the radioactivity was recovered as C 14 O 2 in the expired air, after 20 hours. Also, about one fourth of the administered dose was recovered as unchanged methanol, during the first six hours. Only a minute trace of C 14 -formate was found in the excreta. It is suggested that a catalase-peroxide system is involved in the oxidation of methanol. Ethanol and its metabolites were eliminated at a slower rate than methanol. After 20 hours, C 14 O 2 - being the major C 14 -metabolite - accounted for 56% of the applied dose. In addition, there is at least one minor non-volatile C 14 -metabolite eliminated in the excreta of ethanol-treated larvae.