scholarly journals Kinetic Analysis of Bifidobacterial Metabolism Reveals a Minor Role for Succinic Acid in the Regeneration of NAD+ through Its Growth-Associated Production

2006 ◽  
Vol 72 (8) ◽  
pp. 5204-5210 ◽  
Author(s):  
Roel Van der Meulen ◽  
Tom Adriany ◽  
Kristof Verbrugghe ◽  
Luc De Vuyst
Keyword(s):  
Lactic Acid ◽  
Succinic Acid ◽  
Bifidobacterium Longum ◽  
Product Formation ◽  
Minor Role ◽  
Specific Rate ◽  
Sugar Consumption ◽  
Associated Production ◽  
A Minor

ABSTRACT Several strains belonging to the genus Bifidobacterium were tested to determine their abilities to produce succinic acid. Bifidobacterium longum strain BB536 and Bifidobacterium animalis subsp. lactis strain Bb 12 were kinetically analyzed in detail using in vitro fermentations to obtain more insight into the metabolism and production of succinic acid by bifidobacteria. Changes in end product formation in strains of Bifidobacterium could be related to the specific rate of sugar consumption. When the specific sugar consumption rate increased, relatively more lactic acid and less acetic acid, formic acid, and ethanol were produced, and vice versa. All Bifidobacterium strains tested produced small amounts of succinic acid; the concentrations were not more than a few millimolar. Succinic acid production was found to be associated with growth and stopped when the energy source was depleted. The production of succinic acid contributed to regeneration of a small part of the NAD+, in addition to the regeneration through the production of lactic acid and ethanol.

scholarly journals In Vitro and In Vivo Biology of Recombinant Adenovirus Vectors with E1, E1/E2A, or E1/E4 Deleted

1998 ◽  
Vol 72 (3) ◽  
pp. 2022-2032 ◽  
Author(s):  
M. Lusky ◽  
M. Christ ◽  
K. Rittner ◽  
A. Dieterle ◽  
D. Dreyer ◽  
...  
Keyword(s):  
Recombinant Adenovirus ◽  
Virus Genome ◽  
Minor Role ◽  
Immunodeficient Mice ◽  
Viral Genomes ◽  
Viral Genes ◽  
Adenovirus Vectors ◽  
A Minor

ABSTRACT Isogenic, E3-deleted adenovirus vectors defective in E1, E1 and E2A, or E1 and E4 were generated in complementation cell lines expressing E1, E1 and E2A, or E1 and E4 and characterized in vitro and in vivo. In the absence of complementation, deletion of both E1 and E2A completely abolished expression of early and late viral genes, while deletion of E1 and E4 impaired expression of viral genes, although at a lower level than the E1/E2A deletion. The in vivo persistence of these three types of vectors was monitored in selected strains of mice with viral genomes devoid of transgenes to exclude any interference by immunogenic transgene-encoded products. Our studies showed no significant differences among the vectors in the short-term maintenance and long-term (4-month) persistence of viral DNA in liver and lung cells of immunocompetent and immunodeficient mice. Furthermore, all vectors induced similar antibody responses and comparable levels of adenovirus-specific cytotoxic T lymphocytes. These results suggest that in the absence of transgenes, the progressive deletion of the adenovirus genome does not extend the in vivo persistence of the transduced cells and does not reduce the antivirus immune response. In addition, our data confirm that, in the absence of transgene expression, mouse cellular immunity to viral antigens plays a minor role in the progressive elimination of the virus genome.

Ethanol metabolism by the rat heart and alcohol dehydrogenase activity

1976 ◽  
Vol 54 (6) ◽  
pp. 539-545 ◽  
Author(s):  
G. W. Forsyth ◽  
H. T. Nagasawa ◽  
C. S. Alexander
Keyword(s):  
Alcohol Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Rat Heart ◽  
Specific Activity ◽  
Ph Dependence ◽  
Ethanol Metabolism ◽  
Minor Role ◽  
Alcohol Dehydrogenase Activity ◽  
A Minor

Rat hearts perfused with oxygenated buffer containing [1-14C]ethanol metabolized small amounts of the ethanol to carbon dioxide. Very sensitive techniques are required to separate the resulting 14CO2 from the ethanol. This metabolism is not inhibited by levels of pyrazole which markedly inhibit NAD dependent liver alcohol dehydrogenase (EC 1.1.1.1). In vitro studies suggest that NADP functions as a cofactor for the rat heart alcohol dehydrogenase activity of crude heart homogenates. The kinetic parameters, the specific activity, and the pH dependence of the enzyme activity measured in these experiments suggest that it may have a minor role in ethanol metabolism by the rat.

scholarly journals New Insight into Amphotericin B Resistance in Aspergillus terreus

2013 ◽  
Vol 57 (4) ◽  
pp. 1583-1588 ◽  
Author(s):  
Gerhard Blum ◽  
Caroline Hörtnagl ◽  
Emina Jukic ◽  
Thomas Erbeznik ◽  
Thomas Pümpel ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Molecular Basis ◽  
Aspergillus Terreus ◽  
Minor Role ◽  
Content Type ◽  
Ergosterol Content ◽  
Disseminated Aspergillosis ◽  
A Minor

ABSTRACTAmphotericin B (AMB) is the predominant antifungal drug, but the mechanism of resistance is not well understood. We compared thein vivovirulence of an AMB-resistantAspergillus terreus(ATR) isolate with that of an AMB-susceptibleA. terreusisolate (ATS) using a murine model for disseminated aspergillosis. Furthermore, we analyzed the molecular basis of intrinsic AMB resistancein vitroby comparing the ergosterol content, cell-associated AMB levels, AMB-induced intracellular efflux, and prooxidant effects between ATR and ATS. Infection of immunosuppressed mice with ATS or ATR showed that the ATS strain was more lethal than the ATR strain. However, AMB treatment improved the outcome in ATS-infected mice while having no positive effect on the animals infected with ATR. Thein vitrodata demonstrated that ergosterol content is not the molecular basis for AMB resistance. ATR absorbed less AMB, discharged more intracellular compounds, and had better protection against oxidative damage than the susceptible strain. Our experiments showed that ergosterol content plays a minor role in intrinsic AMB resistance and is not directly associated with intracellular cell-associated AMB content. AMB might exert its antifungal activity by oxidative injury rather than by an increase in membrane permeation.

Endothelial nitric oxide synthase plays a minor role in inhibition of arterial thrombus formation

2005 ◽  
Vol 93 (06) ◽  
pp. 1161-1167 ◽  
Author(s):  
Burcin Özüyaman ◽  
Susanne Küsters ◽  
Elisabeth Kirchhoff ◽  
Rüdiger Scharf ◽  
Jürgen Schrader ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Surface Expression ◽  
No Synthase ◽  
Minor Role ◽  
Endothelial No Synthase ◽  
Tail Tip ◽  
A Minor

SummaryEndothelial NO synthase (eNOS) expressed in the vascular en-dothelium or formed within platelets was postulated to inhibit platelet activation and aggregation. We have assessed the role of eNOS in platelet aggregation in vitro and in vivo by comparison of WT and eNOS-/- mice. Aggregometer studies revealed that collagen over a concentration range of 0.36–10 µg aggregated WT and eNOS-/- platelets to the same extent (10 µg: WT 86.7±4.7%, eNOS-/- 91±12%, n=6). Collagen treatment did not result in a significant increase in cGMP formation and VASP phosphorylation. Thrombin-induced P-selectin surface expression was unchanged in eNOS-/- platelets. In line with these findings no eNOS protein was detectable within the platelets of WT mice. In vivo, bleeding time after tail tip resection tended to be shorter in eNOS/- mice (WT: 116±35 s; eNOS-/- 109±37 s, n.s). Similarly, time to occlusion of the A.carotis after focal induction of thrombosis was 501±76 s (WT) and 457±95 s (eNOS-/-) (n.s.). These data demonstrate that eNOS-deficiency minimally affects platelet aggregation and is not associated with accelerated arterial thrombosis in vivo. Thus, in the mouse endothelial NO synthase does not play a major role in the autocrine modulation of platelet function and in thrombosis of conduit vessels in vivo.

scholarly journals Potential Sustainable Properties of Microencapsulated Endophytic Lactic Acid Bacteria (KCC-42) in In-Vitro Simulated Gastrointestinal Juices and Their Fermentation Quality of Radish Kimchi

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Chae Eun Song ◽  
Han Hyo Shim ◽  
Palaniselvam Kuppusamy ◽  
Young-IL Jeong ◽  
Kyung Dong Lee
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Organic Acids ◽  
Succinic Acid ◽  
Fermentation Medium ◽  
Gastrointestinal Fluid ◽  
Fermentation Quality

The objective of this study was to investigate alginate microencapsulated lactic acid bacteria (LAB) fermentation quality of radish kimchi sample and its potential survivability in different acidic and alkaline environments. Initially, we isolated 45 LAB strains. One of them showed fast growth pattern with potential probiotic and antifungal activities against Aspergillus flavus with a zone of inhibition calculated with 10, 8, 4mm for the 4th, 5th, and 6th day, respectively. Therefore, this strain (KCC-42) was chosen for microencapsulation with alginate biopolymer. It showed potential survivability in in-vitro simulated gastrointestinal fluid and radish kimchi fermentation medium. The survival rate of this free and encapsulated LAB KCC-42 was 6.85 × 105 and 7.48× 105 CFU/ml, respectively; the viability count was significantly higher than nonencapsulated LAB in simulated gastrointestinal juices (acid, bile, and pancreatin) and under radish kimchi fermentation environment. Kimchi sample added with this encapsulated LAB showed increased production of organic acids compared to nonencapsulated LAB sample. Also, the organic acids such as lactic acid, acetic acid, propionic acid, and succinic acid production in fermented kimchi were measured 59mM, 26mM, 14mM, and 0.6mM of g/DW, respectively. The production of metabolites such as lactic acid, acetic acid, and succinic acid and the bacteria population was high in microencapsulated LAB samples compared with free bacteria added kimchi sample. Results of this study indicate that microencapsulated LAB KCC-42 might be a useful strategy to develop products for food and healthcare industries.

scholarly journals Reciprocal Activation by Cyclin-Dependent Kinases 2 and 7 Is Directed by Substrate Specificity Determinants outside the T Loop

2001 ◽  
Vol 21 (1) ◽  
pp. 88-99 ◽  
Author(s):  
Sarah Garrett ◽  
William A. Barton ◽  
Ronald Knights ◽  
Pei Jin ◽  
David O. Morgan ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Protein Interactions ◽  
Phosphorylation Site ◽  
The Body ◽  
Regulatory Subunit ◽  
Minor Role ◽  
Protein Protein Interactions ◽  
Threonine Residue ◽  
A Minor

ABSTRACT Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of the metazoan CDK-activating kinase (CAK), which activates CDKs, such as CDC2 and CDK2, through phosphorylation of a conserved threonine residue in the T loop. Full activation of CDK7 requires association with a positive regulatory subunit, cyclin H, and phosphorylation of a conserved threonine residue at position 170 in its own T loop. We show that threonine-170 of CDK7 is phosphorylated in vitro by its targets, CDC2 and CDK2, which also phosphorylate serine-164 in the CDK7 T loop, a site that perfectly matches their consensus phosphorylation site. In contrast, neither CDK4 nor CDK7 itself can phosphorylate the CDK7 T loop in vitro. The ability of CDC2 or CDK2 and CDK7 to phosphorylate each other but not themselves implies that each kinase can discriminate among closely related sequences and can recognize a substrate site that diverges from its usual preferred site. To understand the basis for this paradoxical substrate specificity, we constructed a chimeric CDK with the T loop of CDK7 grafted onto the body of CDK2. Surprisingly, the hybrid enzyme, CDK2-7, was efficiently activated in cyclin A-dependent fashion by CDK7 but not at all by CDK2. CDK2-7, moreover, phosphorylated wild-type CDK7 but not CDK2. Our results suggest that the primary amino acid sequence of the T loop plays only a minor role, if any, in determining the specificity of cyclin-dependent CAKs for their CDK substrates and that protein-protein interactions involving sequences outside the T loop can influence substrate specificity both positively and negatively.

The Different Genotoxicity of P-Dichlorobenzene in Mouse and Rat: Measurement of the in Vivo and in Vitro Covalent Interaction with Nucleic Acids

1989 ◽  
Vol 75 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Giovanna Lattanzi ◽  
Silvana Bartoli ◽  
Bruna Bonora ◽  
Annamaria Colacci ◽  
Sandro Grilli ◽  
...  
Keyword(s):  
Mouse Liver ◽  
Covalent Binding ◽  
Minor Role ◽  
Covalent Interaction ◽  
Male Wistar Rats ◽  
Mixed Function Oxidase System ◽  
Index Value ◽  
A Minor

Twenty-two hours after i.p. injection to male Wistar rats and BALB/c mice para-dichlorobenzene (p-DCB) is bound covalently to DNA from liver, kidney, lung and stomach of mice but not of rats. DNA adducts in mouse liver are repaired in seventy-two hours. The covalent binding index value, calculated on the labelling of mouse liver DNA, classifies p-DCB as a weak initiator with an oncogenic activity lower than that of chlorobenzene. The labelling of RNA and proteins from the different organs of both species is, however, low. In vitro interaction with calf thymus DNA mediated by mouse and rat microsomes from liver and lung did occur. Binding extent was strongly reduced by addition of 2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride (SKF 525-A) to the microsomal standard incubation mixture, whereas it was enhanced by adding GSH. Cytosolic fractions from kidney and lung were able to induce binding of p-DCB to DNA to a lower extent with respect to microsome-mediated binding. These results indicate that microsomal mixed function oxidase system and microsomal GSH-transferases can be involved in overall activating metabolism whereas cytosolic GSH-transferases play a minor role. This study, which is a part of a structure-activity relationship approach on benzene and its haloderivatives, provides the first evidence of genotoxicity of p-DCB in mammalian cell. It allows to partly explain variations of susceptibility of different species to hepatocarcinogenesis and of hepatotoxicity of different isomers.

scholarly journals RNA binding activates RIG-I by releasing an autorepressed signaling domain

2019 ◽  
Vol 5 (10) ◽  
pp. eaax3641 ◽  
Author(s):  
T. H. Dickey ◽  
B. Song ◽  
A. M. Pyle
Keyword(s):  
Rna Binding ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fluorescent Labeling ◽  
Minor Role ◽  
Signaling Domain ◽  
A Minor ◽  
Dual Site

The retinoic acid–inducible gene I (RIG-I) innate immune receptor is an important immunotherapeutic target, but we lack approaches for monitoring the physical basis for its activation in vitro. This gap in our understanding has led to confusion about mechanisms of RIG-I activation and difficulty discovering agonists and antagonists. We therefore created a novel fluorescence resonance energy transfer–based method for measuring RIG-I activation in vitro using dual site-specific fluorescent labeling of the protein. This approach enables us to measure the conformational change that releases the signaling domain during the first step of RIG-I activation, making it possible to understand the role of stimulatory ligands. We have found that RNA alone is sufficient to eject the signaling domain, ejection is reversible, and adenosine triphosphate plays but a minor role in this process. These findings help explain RIG-I dysfunction in autoimmune disease, and they inform the design of therapeutics targeting RIG-I.

scholarly journals Inhibitors of the Bub1 spindle assembly checkpoint kinase: synthesis of BAY-320 and comparison with 2OH-BNPP1

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Ilma Amalina ◽  
Ailsa Bennett ◽  
Helen Whalley ◽  
David Perera ◽  
Joanne C. McGrail ◽  
...  
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Kinase Activity ◽  
Spindle Assembly ◽  
Minor Role ◽  
Serine Threonine Kinase ◽  
Chromosome Alignment ◽  
A Cell ◽  
A Minor ◽  
Target Effects

Bub1 is a serine/threonine kinase proposed to function centrally in mitotic chromosome alignment and the spindle assembly checkpoint (SAC); however, its role remains controversial. Although it is well documented that Bub1 phosphorylation of Histone 2A at T120 (H2ApT120) recruits Sgo1/2 to kinetochores, the requirement of its kinase activity for chromosome alignment and the SAC is debated. As small-molecule inhibitors are invaluable tools for investigating kinase function, we evaluated two potential Bub1 inhibitors: 2OH-BNPPI and BAY-320. After confirming that both inhibit Bub1 in vitro , we developed a cell-based assay for Bub1 inhibition. We overexpressed a fusion of Histone 2B and Bub1 kinase region, tethering it in proximity to H2A to generate a strong ectopic H2ApT120 signal along chromosome arms. Ectopic signal was effectively inhibited by BAY-320, but not 2OH-BNPP1 at concentrations tested. In addition, only BAY-320 was able to inhibit endogenous Bub1-mediated Sgo1 localization. Preliminary experiments using BAY-320 suggest a minor role for Bub1 kinase activity in chromosome alignment and the SAC; however, BAY-320 may exhibit off-target effects at the concentration required. Thus, 2OH-BNPP1 may not be an effective Bub1 inhibitor in cellulo , and while BAY-320 can inhibit Bub1 in cells, off-target effects highlight the need for improved Bub1 inhibitors.

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