Search results for "DASE"
showing 10 items of 1891 documents
Towards sarcosine determination in urine for prostatic carcinoma detection
2019
Abstract Sarcosine, a potential biomarker for prostate cancer, can be detected in a solid state enzyme based biosensor using sarcosine oxidase, with particle immobilised reagents. A novel fusion protein of the fluorescent protein, mCherry, sarcosine oxidase (SOx), and the polypeptide R5 (R52-mCherry-SOx-R5-6 H), was explored, which allowed self-immobilization on silica microparticles and long-term (90 days +) retention of activity, even at room temperature. In contrast, commercial wildtype SOx lost activity in a few days. A silica-R52-mCherry-SOx-R5-6H microparticle sensor for determination of sarcosine in urine, linked the SOx coproduct, H2O2, to a measurement catalysed by horseradish pero…
Heteroaromatic Inhibitors of the Astacin Proteinases Meprin α, Meprin β and Ovastacin Discovered by a Scaffold-Hopping Approach.
2020
Abstract Astacin metalloproteinases, in particular meprins α and β, as well as ovastacin, are emerging drug targets. Drug‐discovery efforts have led to the development of the first potent and selective inhibitors in the last few years. However, the most recent compounds are based on a highly flexible tertiary amine scaffold that could cause metabolic liabilities or decreased potency due to the entropic penalty upon binding to the target. Thus, the aim of this study was to discover novel conformationally constrained scaffolds as starting points for further inhibitor optimization. Shifting from flexible tertiary amines to rigid heteroaromatic cores resulted in a boost in inhibitory activity. …
Bioinspired Mo, W and V complexes bearing a highly hydroxyl-functionalized Schiff base ligand
2020
Abstract A series of bioinspired dioxidomolybdenum( vi), dioxidotungsten (vi) and oxidovanadium (v) complexes [MoO2(H2LSaltris)], [WO2(H2LSaltris)] and [VO(HLSaltris)]2 were prepared by the reaction of a hydroxyl-rich Schiff base proligand N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)-3,5-di-tert-butylsalicylaldimine (H4LSaltris) with metal precursors in methanol solutions. Molybdenum and tungsten complexes crystallize as mononuclear molecules, whereas the vanadium complex forms dinuclear units. From the complexes, [VO(HLSaltris)]2 shows activity in the oxidation of 4-tert-butylcatechol and 3,5-di-tert-butylcatechol, mimicking the action of the dicopper enzyme catechol oxidase.
Therapeutic dosages of raloxifene do not modify myeloperoxidase and F2alpha-isoprostane levels in postmenopausal women.
2005
We investigated the effect of a therapeutic dose of raloxifene on the plasma levels of myeloperoxidase and F2alpha-isoprostanes, two markers of oxidative stress recently described as reliable indicators of coronary heart disease. Contrary to changes described in the literature for estrogens (E), raloxifene did not modify the levels of either myeloproxidase or F2alpha-isoprostanes after 3 or 6 months of treatment.
Overexpression of apolipoprotein J in human fibroblasts protects against cytotoxicity and premature senescence induced by ethanol and tert-butylhydro…
2008
Human diploid fibroblasts (HDFs) exposed to subcytotoxic stresses under H2O2, tert-butylhydroperoxide (t-BHP), and ethanol (EtOH) undergo stress-induced premature senescence (SIPS) characterized by many biomarkers of HDFs replicative senescence. Among these biomarkers are a growth arrest, an increase in the senescence-associated β-galactosidase activity, a senescent morphology, an overexpression of p21waf-1 and the subsequent inability to phosphorylate pRb, the presence of the common 4977-bp mitochondrial deletion, and an increase in the steady-state level of several senescence-associated genes such as apolipoprotein J (apo J). Apo J has been described as a survival gene against cytotoxic s…
DNA damage causes TP53-dependent coupling of self-renewal and senescence pathways in embryonal carcinoma cells.
2013
Recent studies have highlighted an apparently paradoxical link between self-renewal and senescence triggered by DNA damage in certain cell types. In addition, the finding that TP53 can suppress senescence has caused a re-evaluation of its functional role in regulating these outcomes. To investigate these phenomena and their relationship to pluripotency and senescence, we examined the response of the TP53-competent embryonal carcinoma (EC) cell line PA-1 to etoposide-induced DNA damage. Nuclear POU5F1/OCT4A and P21CIP1 were upregulated in the same cells following etoposide-induced G 2M arrest. However, while accumulating in the karyosol, the amount of OCT4A was reduced in the chromatin fract…
Changes in the Level of Peptidase Activities in Pea Ovaries during Senescence and Fruit Set Induced by Gibberellic Acid
1990
The activities and changes in the levels of exopeptidase and endopeptidase activities were characterized in unpollinated ovaries of Pisum sativum L. cv Alaska during senescence and early fruit development induced by gibberellic acid (GA3). Two aminopeptidases and one iminopeptidase were electrophoretically separated. These peptidases were sensitive to inhibitors of sulfhydryl proteases. Carboxypeptidase activity was inhibited by phenylmethyl sulfonyl fluoride. An azocasein-degrading endopeptidase, sensitive to thiol protease inhibitors, was also found. An increase in the specific activity of aminopeptidase during both fruit development and ovary senescence was observed. In contrast, the spe…
Pharmacological prevention of eNOS uncoupling.
2013
Under physiological conditions, nitric oxide (NO) is produced in the vasculature mainly by the endothelial NO synthase (eNOS). This endothelium-derived NO is a protective molecule with antihypertensive, antithrombotic and anti-atherosclerotic properties. Cardiovascular risk factors such as hypertension, hypercholesterolemia, cigarette smoking and diabetes mellitus induce oxidative stress mostly by stimulation of the NADPH oxidase. Overproduction of reactive oxygen species leads to oxidation of tetrahydrobiopterin (BH4), the essential cofactor of eNOS. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting eNOS to a superoxide- producing enzyme. Consequently, NO …
Prophenoloxidase activating system in tunicate hemolymph
1996
The activation sequence and related factors of the prophenoloxidase activating system in crustaceans was compared with the equivalent system in tunicates. Both solitary and colonial ascidians present in their hemolymph a copper-dependent phenoloxidase activity that may be inhibited by tropolone and phenylthiourea. Carbohydrates are able, to various extents, to trigger proPO system which requires serine protease cleavage for activation to phenoloxidase (PO). In some ascidians, hemocytes called ≪morula cells≫ show PO activity, while in Ciona intestinalis the ≪univacuolar refractile granulocytes≫ are positive after cytochemical staining with L-dopa. The relationships between proPO system and d…
Microbial and histopathological study of the vibriosis caused by Vibrio vulnificus serovar E in eels: The metalloprotease Vvp is not an essential les…
2008
Vibrio vulnificus biotype 2 serovar E (Bt2-serE) is a zoonotic pathogen that causes a haemorrhagic septicaemia in eels, called warm water vibriosis. The main objective of the present work was to study the onset of the eel vibriosis from the microbiological and histopathological viewpoint, as well as to ascertain the role of the protease Vvp as a lesional factor by comparing the histopathological lesions caused by the wild strain and its vvp deficient derivative. The wild-type strain was observed to attach to the gills, where it multiplied following saturation dynamics, subsequently invading the blood stream and reaching the internal organs. Here it reached population sizes that are notably …