Kathepsinaktivit�t in Placenten verschiedener Altersstufen

In Placenten verschiedener Altersstufen wurde nach der Methode vonAnson die Kathepsinaktivitat bestimmt. Dabei zeigte sich, das gegenuber der Fruhgraviditat die Aktivitat am Ende der Schwangerschaft deutlich erniedrigt ist. Bemerkenswert ist die Gruppe der echten Schwangerschaftsubertragungen, die die niedrigsten Werte aufwiesen. Die Differenzen zwischen den einzelnen Gruppen sind statistisch signifikant. Die Bedeutung der Fermentaktivitat fur das Wachstum wird diskutiert.

�ber d-Peptidasen in isolierten Zellkernen

Intracellular location of DNA nucleotidyltransferase.

�ber die enzymatische Glutathionhydrolyse durch isolierte Zellkerne aus Schweineniere

Zellkerne aus Schweineniere vermogen die γ-Peptidbindung in Glutathion unter Freisetzung von Glutaminsaure aufzuspalten.

Über die Hemmung der Arginase durch Stickstofflost

Liver arginase is completely inhibited by nitrogen mustard [tris-(β-chloroethyl)amine, HCl] at a final concentration of 4.6×10−4 M. This holds true for isolated liver cell nuclei also. The experimental conditions are described exactly.

Stoffwechsel von P32-Phosphatiden in isolierten Zellkernen

An isolierten Zellkernen aus Schweineniere in vitro, als einem System, dessen Phosphorumsatz ohne Mitbeteiligung energiereicher Phosphatverbindungen erfolgt, wird gezeigt, das eine Phosphatubertragung von P32-Phosphatiden auf Nukleinsauren und vermutlich auch auf andere phosphorhaltige Verbindungen nicht stattfindet.

Zur Darstellung und Chemie des Hyalin Spieglerscher Tumoren

Über die Hemmung von Desoxyribonucleotide spaltenden Fermenten durch Colchicin

The authors raise the question, if enzymatic processes possibly linked with the mitotic cell division may be influenced by mitotic poisons. The presented date show an inhibition of the dephosphorylation of desoxyribonucleotides at a rate of about 50% and of the deamination of about 40% by colchicine (final concentration 1·2·10−2M).

Enzymatic and Metabolic Studies on Isolated Nuclei

Publisher Summary In protein synthesis it is important to distinguish between the net synthesis of protein, as measured by an increased amount of protein nitrogen or by the formation of proteins with specific biological properties, such as enzymatically and immunologically active proteins, and exchange reactions, which may be observed in isotope experiments and, which reflect the replacement of an amino acid in a protein molecule with one from its environment. Incorporation of an amino acid into a protein can occur only during net synthesis; both types of reaction occur in similar systems. In true synthesis of protein it is usually difficult to obtain synthesis of a specific entity, especia…

Verhalten der Nierenmitochondrien nach intraven�ser Rohrzuckerinjektion bei Ratten

Aktivit�ten von Steroidenzymen in Zellkernen der Rattenleber

Metabolism of reduced pyridine nucleotides in ascites cell nuclei

1. The conditions are described under which the fluorescence due to reduced pyridine nucleotides can be studied separately at nuclear and cytoplasmic sites of glass-grown ascites cells, by the use of a flow chamber in the microfluorimeter ofChance andLegallais.

Isolierung und chemische Charakterisierung von Hyalin ausSpieglerschen Tumoren

Bestimmung von Glykolyse-Metaboliten in isolierten Zellkernen

Isolated rat liver nuclei have been analyzed for the intranuclear concentration of 8 glycolytic metabolites, and in addition for the 3 adenine nucleotides, and for malate. All these substrates are to be found in nuclei in a range of concentration comparable to that in the whole tissue. The consequences of these findings with respect to the definite establishment of glycolysis in isolated nuclei, as well as for the intranuclear formation of energy-rich phosphate bonds, are discussed.

Aktivität Eiweiss spaltender Enzyme in Fischen

Fresh tissues from sea fishes show much higher activities of cathepsins than the corresponding mammalian tissues. The significance of these findings is discussed. There is no indication for the presence in fresh extracts of fish muscle of either proteinases with a pH optimum near neutrality or of decarboxylases for glutamic and aspartic acids. The activities of glycylglycine dipeptidase in fish muscle are found to be at the upper limit of the values obtained by other workers with mammalian tissues.

Thermische Denaturierung von Kaltblüter-Enzymproteinen

The temperature, which leads to 50% reduction of catalytic activity by heat denaturation, has been determined for 8 different enzymes from cod muscle, as being in the range between 30 and 52°C. Therefore, there are no indications of a generally different heat resistance of enzymes from cold-blooded animals as compared with those from warm-blooded animals. The same conclusion is derived from calculations ofQ10-values, measured between +37 and − 37°C for cathepsin and glycylglycine dipeptidase.

Isolierung und chemische Untersuchung von Lipofuscin

Isolierung und Eigenschaften von Lipofuscin aus Herzgewebe des Menschen

Über das Vorkommen von Desoxyribonuclease und Kathepsin in Zellkernen aus Nieren

The authors prepare cell nuclei by a newly developed procedure. Isolated cell nuclei from hog and calf kidney contain almost the whole activity of desoxyribonuclease (depolymerase) of these tissues. — The catheptic activity of isolated cell nuclei from hog kidney is a very considerable one. The importance of these findings is briefly discussed.

High nucleo-cytoplasmic concentration gradient of chloride in rat liver.

PREVIOUSLY, a high nucleo-cytoplasmic concentration gradient of sodium was found in rat liver and other tissues1,2. Since the concentration of potassium also was higher in the nucleus than in the cytoplasm, about 500 µequiv./g dry weight of anions should exist in the nucleus if the assumption is correct that nucleic acids and basic proteins approximately neutralize each other. This communication presents data which demonstrate a high concentration of chloride in the nucleus of the rat-liver cell.

Hemmung der Adenosintriphosphatase durch Colchicin

The ATPase activity is inhibited by Colchicin in concentrations of 10−3 m and 10−4 m at a rate of 40 to 20 %, but in no way in the range of 10−7 m and 10−8 m, where Colchicin exerts its typical spindle-blocking action on the mitotic cell division. It is therefore no evidence, that Colchicin acts by influence on the energy yielding ATP-ATPase system, which was proposed to be responsible for the spindle contraction.

Scientific Proceedings Second International Symposium on Cytostatic Drug Resistance