Search results for "amine"
showing 10 items of 7299 documents
Identification and characterisation of the dopamine receptor II from the cat flea Ctenocephalides felis (CfDopRII)
2006
International audience; G protein-coupled receptors (GPCRs) represent a protein family with a wide range of functions. Approximately 30% of human drug targets are GPCRs, illustrating their pharmaceutical relevance. In contrast, the knowledge about invertebrate GPCRs is limited and is mainly restricted to model organisms like Drosophila melanogaster and Caenorhabditis elegans. Especially in ectoparasites like ticks and fleas, only few GPCRs are characterised. From the cat flea Ctenocephalides felis, a relevant parasite of cats and dogs, no GPCRs are known so far. Thus, we performed a bioinformatic analysis of available insect GPCR sequences from the honeybee Apis mellifera, the mosquito Anop…
The Effect of Metal Cations on the Aqueous Behavior of Dopamine. Thermodynamic Investigation of the Binary and Ternary Interactions with Cd2+, Cu2+ a…
2021
The interactions of dopamine [2-(3,4-Dihydroxyphenyl)ethylamine, (Dop−)] with cadmium(II), copper(II) and uranyl(VI) were studied in NaCl(aq) at different ionic strengths (0 ≤ I/mol dm−3 ≤ 1.0) and temperatures (288.15 ≤ T/K ≤ 318.15). From the elaboration of the experimental data, it was found that the speciation models are featured by species of different stoichiometry and stability. In particular for cadmium, the formation of only MLH, ML and ML2 (M = Cd2+; L = dopamine) species was obtained. For uranyl(VI) (UO22+), the speciation scheme is influenced by the use of UO2(acetate)2 salt as a chemical; in this case, the formation of ML2, MLOH and the ternary MLAc (Ac = acetate) species in a …
Asymmetric Oxidative Mannich Reactions
2020
The asymmetric Mannich reaction is one of the most straightforward methodologies for the enantioselective synthesis of chiral amines. In general, asymmetric Mannich reactions involve the use of imines as electrophiles. However, in recent years, several asymmetric oxidative Mannich reactions have been reported using amines as electrophiles. This review provides an overview of these recent publications, including the different oxidants used and the scope and limitations of the different catalytic systems.
Immigrant entrepreneur firm start-up behavior and reasoning : a reflective study of causation, effectuation and bricolage
2013
Entrepreneurship research studies how and why firms come into being, survive and grow (Davidsson, 2004; Gartner, 1985; Schumpeter, 1934). Early literature has proposed a linear model of entrepreneurship which is intentional (Bird, 1988), opportunity discovery (Kirzner, 1997; Shane and Venkataraman, 2000) and goal & strategy oriented (Wiklund & Shepherd, 2005). Being a mainstream in the earlier research, it is labelled as causation model by Sarasvathy (2001). Several scholars such as Baker & Nelson (2005) and Sarasvathy (2001a, b; 2008) questioned the validity of the model and proposed two additional models to the classic model: Effectuation (Sarasvathy, 1998) and Entrepreneurial Bricolage (…
Suomi toisena kielenä -oppijoiden sanaston kehittyminen taitotasolta toiselle siirryttäessä
2012
Tutkimuksen tavoitteena on selvittää, kuinka sanaston käyttö kehittyy suomi toisena kielenä -oppijoiden teksteissä. Tarkastelun kohteena on sanavaraston rikkaus eli leksikaalinen diversiteetti. Aineistona on 1197 aikuisten ja koululaisten eri tekstilajeja edustavaa kirjoitusta, jotka on arvioitu valmiiksi Eurooppalaisen viitekehyksen mukaisille taitotasoille. Työ on osa Suomen Akatemian ja Jyväskylän yliopiston vuosina 2007-2009 rahoittamaa Cefling hanketta, jonka tehtävänä on selvittää, millaista kielitaito on kullakin Eurooppalaisessa viitekehyksessä kuvatulla kuudella taitotasolla. Tavoitteena on myös selvittää, onko aikuisten ja koululaisten kielenoppimisessa eroja. Keskeisimmät teoreet…
Sphingomyelin inhibition of Ciona intestinalis (Tunicata) cytotoxic hemocytes assayed against sheep erythrocytes
1995
Hemocytes from the ascidian, Ciona intestinalis, are capable of lysing erythrocytes in vitro following cell membrane contact. With the aim of examining the mechanism of cytotoxicity, we performed inhibition experiments with lipid components of erythrocyte membranes. Cholesterol is not an inhibitor, whereas, among the phospholipids tested, (sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine) sphingomyelin inhibits the hemolytic activity of hemocytes. However, thin layer chromatography showed that sphingomyelinase activity was not contained in the chloroform-methanol extracts from hemocyte debris. The inhibition capacity of the components ceramide and phosphorylc…
Transglutaminase activity is involved in Saccharomyces cerevisiae wall construction
2002
Transglutaminase activity, which forms the interpeptidic cross-link N(epsilon)-(gamma-glutamyl)-lysine, was demonstrated in cell-free extracts of Saccharomyces cerevisiae by incorporation of [(14)C]lysine into an exogenous acceptor, N,N'-dimethylcasein. Higher levels of the activity were present in the cell wall, which also contained endogenous acceptors. The enzyme activity in the wall was inhibited by cystamine, a known inhibitor of transglutaminase, and by EDTA, indicating a cation-dependent activity. After the endogenous wall acceptors were labelled radioactively by transglutaminase, extraction with SDS solubilized about 50% of the total radioactivity, while Zymolyase and chitinase each…
Concepts to Reveal Parvovirus–Nucleus Interactions
2021
Parvoviruses are small single-stranded (ss) DNA viruses, which replicate in the nucleoplasm and affect both the structure and function of the nucleus. The nuclear stage of the parvovirus life cycle starts at the nuclear entry of incoming capsids and culminates in the successful passage of progeny capsids out of the nucleus. In this review, we will present past, current, and future microscopy and biochemical techniques and demonstrate their potential in revealing the dynamics and molecular interactions in the intranuclear processes of parvovirus infection. In particular, a number of advanced techniques will be presented for the detection of infection-induced changes, such as DNA modification…
Uridine enhances the cytotoxic effect of D-glucosamine in rat C6 glioma cells.
1986
This paper studies the influence of uridine on the effects exerted by D-glucosamine in rat C6 glioma cells. 2 mM uridine increased markedly both the cytotoxic effect of the aminosugar and the inhibition of thymidine incorporation into acid-insoluble fraction. Furthermore the complete resumption of the capacity to incorporate either 3H-thymidine or 3H-mannose which was observed after the removal of the aminosugar, was impeded when the cells were treated contemporaneously with D-glucosamine and uridine. An exposure for 4 hr to 20 mM glucosamine alone enhanced about 15-fold the cellular pool of UDP-N-acetylhexosamines; the addition of 2 mM uridine intensified the expansion of this pool, which …
Galantamine modulates nicotinic receptor and blocks Aβ-enhanced glutamate toxicity
2004
Galantamine is a plant alkaloid that is used in the treatment of Alzheimer's disease. We have studied the effects of galantamine on beta-amyloid-enhanced glutamate toxicity using primary rat cultured cortical neurons. Nicotine and galantamine alone, and in combination, protected neurons against this neurotoxicity. The protection was not blocked by alpha4beta2 nicotinic acetylcholine receptor (nAChR) antagonists, but was partially blocked by alpha7 nAChR antagonists. Galantamine induced phosphorylation of Akt, an effector of phosphatidylinositol 3-kinase (PI3K), while PI3K inhibitors blocked the protective effect and Akt phosphorylation. The antibody FK1, which selectively blocks the alloste…