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Results 301 - 350 of 1660
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Liu Guang-shen - - 2004
The main effects of pollutions including acid rain, Cu2+, atrazine and their combined products on the activities of urease, invertin, acid phosphatase and catalase were studied by means of orthogonal test. The results showed that H+ and Cu2+ had significant influence on the activities of four enzymes and the ability ...
Abe Koji - - 2004
Pyroglutamyl aminopeptidase I (PAP-I) is known for specifically removing the L-pyroglutamate (L-pGlu) residue from the amino terminus of L-pGlu proteins and peptides. In general, substrate recognition of PAP-I as to L-pGlu moiety is tightly regulated. However, we recently identified PAP-I as a metabolic enzyme of an organic nitrate compound, RS-7897, ...
Custódio Ana Maria Galvan - - 2004
The prostate is present in both male and female mammals. It is composed of secretory epithelium, connective stroma, smooth muscle and neuroendocrine cells, which are under hormonal regulation. Acid phosphatases catalyze the hydrolysis of orthophosphate monoesters. We have compared the expression of acid phosphatases in gerbil (Meriones unguiculatus) prostate glands ...
Marcon Edyta - - 2003
With the phosphatase inhibitor, okadaic acid, we induce the precocious onset of the chiasmate stage and under those conditions show that the recombination nodules, MLH1 and MLH3 foci, are localized to the chiasmata. It is concluded that MLH1/3 foci are appropriate markers for the studies of crossovers/chiasmata development and distribution ...
Tsvetkov I L - - 2003
Acid phosphatases differing in both subcellular localization and substrate specificity were isolated for the first time from the liver of the freshwater snail Viviparus viviparus L. by preparative isoelectrofocusing. One of five characterized phosphatases is highly specific to ADP and the others can hydrolyze (at variable rate) a series of ...
Contín María A - - 2003
The association of tubulin carboxypeptidase with microtubules may be involved in the determination of the tyrosination state of the microtubules, i.e. their proportion of tyrosinated vs. nontyrosinated tubulin. We investigated the role of protein phosphatases in the association of carboxypeptidase with microtubules in COS cells. Okadaic acid and other PP1/PP2A ...
Zhang Hai-Rong - - 2003
The influence of different denaturants on the phosphorescence spectrum and lifetime decay of Escherichia coli alkaline phosphatase (AP) was investigated. Phosphorescence intensity and lifetime of tryptophan residue (Trp-109) decrease upon addition of guanidine hydrochloride, ethylene diamine tetraacetic acid, and urea or decreasing acidity. The experiments show that AP undergoes different ...
Oh B-C - - 2004
Phytases are a special class of phosphatase that catalyze the sequential hydrolysis of phytate to less-phosphorylated myo-inositol derivatives and inorganic phosphate. Phytases are added to animal feedstuff to reduce phosphate pollution in the environment, since monogastric animals such as pigs, poultry, and fish are unable to metabolize phytate. Based on ...
Prigent Stéphane - - 2003
Understanding the significance of electrophoretic variation is of interest for both ecological and evolutionary genetics. Although there has been a very active neutralist-selectionist debate about the patterns of electrophoretic variation in natural populations, it is only recently that charged amino acids have been shown to be important in enzyme adaptation. ...
Tamura Tadashi - - 2003
We found that the treatment with 1 mM butyric acid for 2 days renders Vero cells highly sensitive to ricin-induced apoptosis reflected by cytolysis concomitant with apoptotic cellular and nuclear morphological changes, DNA fragmentation, and increase in caspase-3 like activity, whereas butyric acid alone had no cytotoxic effect on Vero ...
Kondomerkos D J - - 2003
Peritoneal and bronchoalveolar macrophages activated in vitro by endotoxin, exhibit alterations in the acid phosphatase activity of cell lysates when certain hormones or autacoids are present in the culture medium. They also show morphological changes concerning general appearance and acid phosphatase cytochemistry. Certain agents known to increase the intracellular levels ...
Teiber John F - - 2003
Human paraoxonase (PON1) was previously shown to hydrolyze over 30 different lactones (cyclic esters). In the present study purified human PON1 was found to catalyze the reverse reaction (lactonization) of a broad range of hydroxy acids. Hydroxy acid lactonization or lactone hydrolysis is catalyzed until equilibrium between the open and ...
Trouverie Jacques - - 2003
Among the numerous molecular and physiological modifications induced by water deficit, one of the earliest events observed in maize mature leaves subjected to water deprivation was a strong enhancement of acid vacuolar invertase activity, which occurred before the classical reduction in gas exchange due to stomatal closure. The increase in ...
Kölzer Melanie - - 2003
Acid sphingomyelinase (A-SMase, EC 3.1.4.12) catalyzes the lysosomal degradation of sphingomyelin to phosphorylcholine and ceramide. Inherited deficiencies of acid sphingomyelinase activity result in various clinical forms of Niemann-Pick disease, which are characterised by massive lysosomal accumulation of sphingomyelin. Sphingomyelin hydrolysis by both, acid sphingomyelinase and membrane-associated neutral sphingomyelinase, plays also ...
Al-Adhami B H - - 2003
A variety of fluorescent probes have been used to study the acidic compartments in cercariae and schistosomula of Schistosoma mansoni. Freshly transformed schistosomula treated with the LysoTracker Red dye specific for lysosomes showed large acid-containing compartments (0.5-10 microm in size). The uptake of the dye is an energy-dependent process that ...
Tanaka Naoko - - 2003
Nonspecific acid phosphatases share a conserved active site with mammalian glucose-6-phosphatases (G6Pase). In this work we examined the kinetics of the phosphorylation of glucose and dephosphorylation of glucose-6-phosphate (G6P) catalysed by the acid phosphatases from Shigella flexneri (PhoN-Sf) and Salmonella enterica (PhoN-Se). PhoN-Sf is able to phosphorylate glucose regiospecifically to ...
Swierczek Krzysztof - - 2003
Phosphorothioates, analogues of phosphate esters in which a sulfur replaces an oxygen atom in the phosphoryl group, are competent surrogate substrates for a number of phosphatases. In some cases the thio analogues show similar binding (as estimated by K(m)) while other phosphatases show quite different K(m) values for phosphate compared ...
Nozawa S R - - 2003
In this communication, we show that the pacC(c)14 mutation drastically reduced the mannose and N-acetylglycosamine content of the pacA-encoded acid phosphatase secreted by the fungus Aspergillus nidulans when grown at 22 degrees C, pH 5.0, compared to a control strain. The staining after PAGE was not observed for the pacA-encoded ...
Møller Michael T N - - 2003
Glycine N-methyltransferase (GNMT) is an abundant cytosolic enzyme that catalyses the methylation of glycine into sarcosine, coupled with conversion of the methyl donor, S -adenosylmethionine (AdoMet), into S -adenosylhomocysteine (AdoHcy). GNMT is believed to play a role in monitoring the AdoMet/AdoHcy ratio, and hence the cellular methylation capacity, but regulation ...
Kusudo Tatsuya - - 2003
Purple acid phosphatase (PAP) was purified from sweet potato dry powder, which is used as a food additive. Spectrometric and enzymatic analyses, and analysis of the amino-terminal sequence indicated that the purified purple acid phosphatase was PAP1. High activity in neutral and acidic conditions, broad substrate specificity, and good thermal ...
Marquínez A C - - 2003
The decapacitating fraction of human seminal plasma, which strongly interacts with concanavalin A, is constituted by high mannose-type N-linked glycoproteins, most of them of less than 44 kDa. Each component with apparent molecular mass of 30, 18, and 17 kDa respectively, as judged by SDS-PAGE, was submitted to "in gel" ...
Seufferheld Manfredo - - 2003
Acidocalcisomes are acidic calcium storage compartments described in several unicellular eukaryotes, including trypanosomatid and apicomplexan parasites, algae, and slime molds. In this work, we report that the volutin granules of Agrobacterium tumefaciens possess properties similar to the acidocalcisomes. Transmission electron microscopy revealed that each intracellular granule was surrounded by a ...
Le Hegarat Ludovic - - 2003
Okadaic acid (OA) is a major toxin involved in diarrhetic shellfish poisoning in humans and has been shown to be both a potent tumor promoter in rodent skin and stomach and an inhibitor of serine/threonine protein phosphatases, specifically PP1 and PP2A. The research on the genotoxic potential of OA amounts ...
Sassa Shuji - - 2003
An extract from corn germ induced a positive response in the pigeon crop sack test, used for the detection of prolactin-like substances. One of the substances extracted was identified as ferulic acid, which was reported to affect serum gonadotropin levels in ovariectomized male rats. To evaluate the effects of ferulic ...
Lad Chetan - - 2003
To evaluate the proficiency of phosphatases as catalysts, the rate of the uncatalyzed hydrolysis of simple phosphate monoester dianions was estimated by extrapolating rates measured over a range of high temperatures. The rate of spontaneous hydrolysis of phenyl phosphate dianion indicates that a linear free energy relationship reported earlier is ...
Borelli G - - 2003
The soluble organic matrix (OM) of various biominerals (red coral skeleton, oyster shell, sea urchin test, turbot otolith, chicken eggshell) was extracted after demineralization with acetic acid. The protein content of the OM varies strongly from 0.02 to 1.6 microg/mg biomineral whereas proteoglycans present less variations (from 0.7 to 1.4 ...
Shakarian Alison M - - 2003
Recently, we identified and characterized the genes encoding several distinct members of the histidine-acid phosphatase enzyme family from Leishmania donovani, a primitive protozoan pathogen of humans. These included genes encoding the heavily phosphorylated/glycosylated, tartrate-sensitive, secretory acid phosphatases (Ld SAcP-1 and Ld SAcP-2) and the unique, tartrate-resistant, externally-oriented, surface membrane-bound acid ...
Aleksieva Penka - - 2003
Acid phosphatase activities in a culture liquid and mycelial extract were studied in submerged cultures of the filamentous fungus Humicola lutea 120-5 in casein-containingmedia with and without inorganic phosphate (Pi). The Pi-repressible influence on the phosphatase formation was demonstrated. Significant changes in the distribution of acid phosphatase between the mycelial ...
Pattingre Sophie - - 2003
Activation of ERK1/2 stimulates macroautophagy in the human colon cancer cell line HT-29 by favoring the phosphorylation of the Galpha-interacting protein (GAIP) in an amino acid-dependent manner (Ogier-Denis, E., Pattingre, S., El Benna, J., and Codogno, P. (2000) J. Biol. Chem. 275, 39090-39095). Here we show that ERK1/2 activation by ...
Yamahama Y - - 2003
The present study was designed to investigate the process of acidification of yolk granules during embryogenesis. In oocytes of mature Bombyx mori silkmoth, yolk proteins and a cysteine protease (pro-form BCP) were found in yolk granules. BCP was localized in small sized yolk granules (SYG, 3-6 microm in diameter) and ...
Schadeck Ruth Janice Guse - - 2003
Vacuoles of ungerminated Colletotrichum graminicola conidia engulf cytoplasmic structures by a process analogous to microautophagy, demonstrated by using a vacuolar membrane acid phosphatase marker. Fusion of vesicles with vacuoles, without deposition of the acid phosphatase reaction product has been observed, suggesting other pathways of material delivery to vacuoles than microautophagy. ...
Nakagami Yoshihiro - - 2003
DNase II is involved in DNA fragmentation induced by a variety of treatments. However, according to past reports DNase II does not directly generate TUNEL (in situ DNA end labeling)-positive cells. The purpose of this study was to investigate the participation of acid phosphatase in the generation of TUNEL-positive cells. ...
Gallardo-Williams Maria T - - 2003
BACKGROUND: Prostate specific antigen (PSA) is a well-established marker of prostate cancer, but it can also degrade extracellular matrix proteins such as fibronectin and could be involved in tumor progression and metastasis. In this study, we have addressed the use of boric acid and 3-nitrophenyl boronic acid (NPBA) as PSA ...
Mitsuishi Hiroko - - 2003
Okadaic acid (OA) decreased the leptin content in isolated mouse fat pads in a time and dose-dependent manner. MG-132, a membrane-permeable proteasome inhibitor, prevented the decrease by OA, suggesting the involvement of proteasome in the OA action. No significant decrease in the incorporation of [(3)H]leucine into leptin was observed with ...
Sevenou O - - 2002
Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) was used to study the external regions of starch granules. Native starches (wheat, potato, maize, waxy maize and amylomaize) were analysed and compared to gelatinised and acid-hydrolysed starches. The IR spectra of potato and amylomaize starches were closer to that of highly ordered acid-hydrolysed ...
Dubbelhuis Peter F - - 2002
Amino acid-induced cell swelling stimulates conversion of glucose into glycogen in isolated hepatocytes. Activation of glycogen synthase (GS) phosphatase, caused by the fall in intracellular chloride accompanying regulatory volume decrease, and activation of phosphoinositide 3-kinase (PI 3-kinase), induced by cell swelling, have been proposed as underlying mechanisms. Because PI 3-kinase ...
Haux J Eric - - 2002
Butyrylcholinesterase (BChE) is inhibited by the plant growth regulator (2-chloroethyl)phosphonic acid (ethephon) as observed 25 years ago both in vitro and in vivo in rats and mice and more recently in subchronic studies at low doses with human subjects. The proposed mechanism is phosphorylation of the BChE active site at ...
Piquemal Joel - - 2002
Transgenic maize (Zea mays) plants were generated with a construct harboring a maize caffeic acid O-methyltransferase (COMT) cDNA in the antisense (AS) orientation under the control of the maize Adh1 (alcohol dehydrogenase) promoter. Adh1-driven beta-glucuronidase expression was localized in vascular tissues and lignifying sclerenchyma, indicating its suitability in transgenic experiments ...
Helmann John D - - 2002
Helmann discusses the controversy surrounding the activation of the bacterial redox-regulated transcription factor OxyR. Evidence from different sources, including crystallographic data, has led to opposing models for the chemical changes that activate OxyR. Is it an intramolecular disulfide-linkage? Is it oxidation of a single cysteine residue to a sulfenic acid? ...
Dounay A B - - 2002
As the first recognized member of the "okadaic acid class" of phosphatase inhibitors, the marine natural product okadaic acid is perhaps the most well-known member of a diverse array of secondary metabolites that have emerged as valuable probes for studying the roles of various cellular protein serine/threonine phosphatases. This review ...
Partanen Seppo - - 2002
Fluoride is considered to be a nephrotoxic substance, due to the association of 50-180 microM serum concentrations of fluoride with dose-related, subclinical to overt clinical renal impairment. At these concentrations the cellular targets of fluoride in renal tissue remain unknown. Fluoride at micromolar concentrations inhibits some enzymes including phosphatases. Here ...
Olsson Pål Axel - - 2002
The influence of external phosphorus (P) on carbon (C) allocation and metabolism as well as processes related to P metabolism was studied in monoxenic arbuscular mycorrhiza cultures of carrot (Daucus carota). Fungal hyphae of Glomus intraradices proliferated from the solid minimal medium containing the colonized roots into C-free liquid minimal ...
Edqvist Johan - - 2003
The endosperm of Euphorbia lagascae Spreng. seeds contains high levels of the epoxidated fatty acid vernolic acid [12(S),13(R)-epoxy-12-octadecenoic acid]. To learn more about the function and metabolism of vernolic acid, we have initiated an investigation into the gene activities involved in the processes of vernolic acid mobilization and oxidation during ...
Romanowska-Duda Zdzisława - - 2002
The eutrophication of the Sulejów Reservoir dam in Poland is related to toxicity from cyanobacterial blooms. The main species responsible for hepatotoxic bloom formation is Microcystis aeruginosa. The aim of this study was to evaluate the influence of toxic cyanobacterial extract on the growth and morphology of the water plant ...
Klumpp Susanne - - 2002
The cellular composition and concentration of fatty acids are crucial for proliferation and survival. We recently showed stimulation of protein phosphatase type-2C (PP2C) by unsaturated fatty acids. Here, we describe that treatment of cultured chick neurons with 100 microM oleic acid for 24h increased the percentage of damaged neurons to ...
Foissner Ilse - - 2002
We investigated the cytoskeleton of Lilium longiflorum pollen tubes and examined the effects of the type 2A protein phosphatase (PP2A) inhibitors calyculin A and okadaic acid. An improved method for actin visualization, the simultaneous fixation and staining with rhodamine-labelled phalloidin during microscopical observation, revealed abundant actin filaments of no preferential ...
Qi Xiaoyang - - 2002
Saposin C is a biological activator of acid beta-glucosidase (GCase), the lysosomal hydrolase with activity towards glucosylceramide (GC). In addition, saposin C possesses a functional domain that determines the in vitro and ex vivo neuritogenic effects of prosaposin, the precursor of saposins A, B, C, and D. The domains for ...
Kalamidas S A - - 2002
The effects of agents that could manipulate the lysosomal calcium such as phorbol myristate acetate, ionophore A23187, and phentolamine on the lysosomal glycogen degradation were studied by electron microscopy, morphometric analysis, and biochemical assays in newborn rat hepatocytes. Phorbol myristate acetate, which promotes the input of calcium to lysosomes, increased ...
Martínez-Grueiro M M - - 2002
Acid phosphatase (AP) activity was detected in 24 h culture media from adult Heligmosomoides polygyrus. Female and male excretion/secretion products showed similar specific activity. For both, the AP had a pH optimum of 4.0 and was inhibited by sodium fluoride, tartaric acid, and sodium orthovanadate. The release of AP by ...
Waheed Abdul - - 2002
BACKGROUND: The level of prostatic acid phosphatase in serum is an established marker for prostate carcinoma. METHODS: Inactivation of homogeneous prostatic acid phosphatase from human seminal fluid by purified plasmin and human serum was studied in the presence and absence of bovine pancreatic trypsin inhibitor, a plasmin inhibitor, or phenylmethylsulfonylfluoride, ...
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