Search results for "KINASE"

Species-Specific Aggregation Factor In Sponges.

1978

In dissociated single cells from the sponge Geodia cydonium, DNA synthesis is initiated after incubation with a homologous, soluble aggregation factor. During the DNA-initiation phase the cyclic AMP- and cyclic GMP levels vary drastically; the cyclic AMP content drops from 2.2 pmol/10(6) cells to 0.3 pmol/10(6) cells while the cyclic GMP content increases from 0.6 pmol to 3.7 pmol/10(6) cells. The activity of neither the adenylate cyclase nor of the guanylate cyclase isolated from cells which have been incubated for different periods of time with the aggregation factor, is changed. The soluble as well as the particulate enzyme activities were checked in vitro. The cyclic nucleotide receptor…

Kinetic and functional characterization of a membrane-bound NAD(P)H dehydrogenase located in the chloroplasts of Pleurochloris meiringensis (Xanthoph…

1996

Using isolated chloroplasts or purified thylakoids from photoautotrophically grown cells of the chromophytic alga Pleurochloris meiringensis (Xanthophyceae) we were able to demonstrate a membrane bound NAD(P)H dehydrogenase activity. NAD(P)H oxidation was detectable with menadione, coenzyme Q0, decylplastoquinone and decylubiquinone as acceptors in an in vitro assay. K m-values for both pyridine nucleotides were in the μmolar range (K m[NADH]=9.8 μM, K m[NADPH]=3.2 μM calculated according to Lineweaver-Burk). NADH oxidation was optimal at pH 9 while pH dependence of NADPH oxidation showed a main peak at 9.8 and a smaller optimum at pH 7.5-8. NADH oxidation could be completely inhibited with…

2003

Jerboa (Jaculus orientalis) is a deep hibernating rodent native to subdesert highlands. During hibernation, a high level of ketone bodies i.e. acetoacetate (AcAc) and D-3-hydroxybutyrate (BOH) are produced in liver, which are used in brain as energetic fuel. These compounds are bioconverted by mitochondrial D-3-hydroxybutyrate dehydrogenase (BDH) E.C. 1.1.1.30. Here we report, the function and the expression of BDH in terms of catalytic activities, kinetic parameters, levels of protein and mRNA in both tissues i.e brain and liver, in relation to the hibernating process. We found that: 1/ In euthemic jerboa the specific activity in liver is 2.4- and 6.4- fold higher than in brain, respective…

Alterations inras-gene expression and intracellular distribution of protein kinase C in the spongeGeodia cydonium in response to marine pollution

1990

The siliceous spongeGeodia cydonium Jameson was used to study the influence of pollution in marine environments on selected parameters of the intracellular signal transduction pathway. The parameters chosen were: intracellular distribution of protein kinase C (PK-C),ras-gene expression and DNA polymerasealpha (DNA Polalpha) activity. Both PK-C andras-gene product (ras-protein) have previously been established to be key molecules in the intracellular signalling pathway in sponges; increased level ofras-protein mediates events following sponge cell-cell contact. Three unpolluted and three polluted sites in the off-shore seawater around Rovinj (Yugoslavia) were selected for the study in 1989. …

STUDIES ON NAD- AND NADP- DEPENDENT ENZYMES IN PERIPHERAL NERVE

1966

Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains ofSaccharomyces cerevisiaeand interspecies hybrids

2015

The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the p…

Der cytochemische Nachweis von Prolin-Dehydrogenasen, Acetaldehyd-Dehydrogenasen und Dihydrolipons�ure-Dehydrogenase in den Zellen vonSaccharomyces c…

1967

Using the tetrazolium salt Nitro-BT, the following dehydrogenases can be demonstrated cytochemically in the cells ofSaccharomyces cerevisiae: (1)Proline dehydrogenase activity: it cannot be decided whether the formazan production is a result of L-proline: NAD(P)-2-oxidoreductase (E.C. 1.5.1.1) or of L-proline:NAD(P)-5-oxidoreductase(E.C. 1.5.1.2); (2)Aldehyde dehydrogenase activity: using the coenzymes NAD and NADP and the activators KCl and MgCl2, different reaction pictures are obtained which led to the conclusion that aldehyde: NADP oxidoreductase (E.C. 1.2.1.4) and aldehyde: NAD(P) oxidoreductase (E.C. 1.2.1 5) can be demonstrated seperately; (3)Dihydrolipoic dehydrogenase (E.C. 1.6.4.3…

Kinetic properties of a nucleoside phosphotransferase of chick embryo

1981

1. A nonspecific nucleoside phosphotransferase (nucleotide : 3'-deoxynucleotide 5'-phosphotransferase, EC 2.7.1.77), purified from chick embryos, catalyzes the transfer of phosphate ester from a nucleotide donor to a nucleoside acceptor. 2. The enzyme exhibits sigmoidal kinetics with respect to nucleoside monophosphate donors, but with respect to nucleoside di- or triphosphate donors and nucleoside acceptors hyperbolic kinetics were obtained. 3. The nucleoside phosphotransferase of chick embryo is unstable to heat and is protected from inactivation by a large number of nucleosides. 4. Nucleoside di- and triphosphates lower both the concentration of nucleoside monophosphates required for hal…

Cyclic voltammetric analysis of pH-dependent complex formation equilibria in anion coordination chemistry

1995

A procedure to analyze pH-dependent complex formation equilibria from cyclic voltammetry is described. Application to adduct formation equilibria between [Fe(CN)(6)](4-) and [Fe(CN)(6)](3-) with different polyammonium receptors is discussed. Extension to the interaction of substrates such as ATP, NAD(+), NADP(+), and carboxylate ions with these receptors by means of competitive interaction with hexacyanoferrate(II) ion is presented.

Interrelationships between Growth Yield, ATPase and Adenylate Kinase Activities inZymomonas mobilis

2001

The presence of cytoplasmic and membrane-bound adenylate kinase (EC 2.7,4.3) as well as inorganic pyrophosphatase (EC 3.6.1.1) was detected in Zymomonas mobilis ATCC 29191. An increase in the molar growth yield (Y X/S ) of Z. mobilis under aerobic growth conditions appeared to be in proportion to a reduction of membrane-bound adenylate kinase (mAK) and ATPase activities and to an increase in cytoplasmic adenylate kinase (AK) activity. Significant (1 - P < 0.01) multiple regressions were observed between the values of Y x (dependent variable), ATPase and AK or AK and mAK as independent variables, suggesting that a combined operation of these phosphohydrolases and phosphotransferases would be…