bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dexamethasone induced expression of phosphatase inhibits generation of reactive oxygen species in ehrlich ascietes tumor cells
Authors: Salimath Bharathi P. , Sharma Ranjana , Tabassum Arshia 
Published: July 2007

AbstractBoth pre‐activated and phorbol ester tetradecanoyl phorbol myristate acetate (TPA) activated reactive oxygen species (ROS) generation were inhibited by dexamethasone in viva. Time kinetics on influence of dexamethasone on cytosolic phosphoprotein phosphatase activity revealed that, when compared to phosphatase activity in cytosol of control Ehrlich ascites tumor (EAT) cells, a 5‐fold increase in specific activity is seen in the cytosol of EAT cells treated (in viva, 0‐90 min. 1 mg/kg body weight) with dexamethasone. Dexamethasone induced phosphatase was partially purified by conventional ion‐exchange and gel filtration column chromatographic techniques. Purified phosphatase had a molecular weight of 70 KDa by SDS‐PAGE. A dose‐dependent inhibition of TPA activated ROS generation by partially purified phosphatase in permeabilized EAT cells suggested that dephosphorylation is a major regulatory mechanism in “switching off” of the respiratory burst. Anti‐phosphatase antibodies were raised, purified and were used to quantitate cytosolic phosphatase by ELISA, which revealed that dexamethasone induces 6‐fold increase in expression of phosphatase in EAT cells by 120 min. The expression of phosphatase in EAT cell cytosol gas further confirmed by immunostaining using anti‐phosphatase antibodies, the results of which showed intense blue staining on development with BCIP/NBT.
Purification and partial characterization of thioredoxin reductase from Streptomyces aureofaciens
Authors: Horecká Tatiana , Perecko Dusan , Kutejová Eva , Mikulásová Darina , Kollárová Marta 
Published: July 2007

AbstractThioredoxin reductase (TrxR) is one of a number of flavoproteins that catalyze the transfer of electrons between pyridine nucleotides and a specific disulfide‐containing substrate. Thioredoxin reductase from Streptomyces aureofaciens 3239 has been purified to homogeneity by a two‐step chromatographic procedure including anion‐exchange chromatography and affinity chromatography on 2′5′‐ADP‐Sepharose 4B. Molar mass determined by chromatography on Superose 12 HR 10/30 and sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed 69 kDa for the native protein and 34.8 kDa for the enzyme subunit. The isoelectric point determined by isoelectric focusing gel electrophoresis was 4.3. TrxR effectively catalyzed the reduction of DTNB in the presence of S. aureofaciens thioredoxin‐1. TrxR activity in the presence of S. aureofaciens thioredoxin‐2 was only 1/4 of the activity with thioredoxin‐1 (1). The activity of pure TrxR decreased drastically in the presence of NADPH, while NADP+ as well as Streptomyces aureofaciens thioredoxin‐1 protected the enzyme from inactivation. These results indicate that thioredoxin reductase activity in bacteria could be modulated by the redox status of NADP+/NADPH and thioredoxin pools.
Site‐directed mutagenesis and steady‐state kinetic analysis of mutant enzymes of human adenylate kinase
Authors: Ayabe Takanori , Park Seung Kyu , Nagahama Hiroyuki , Maruyama Hideharu , Sumida Michihiro , Takenaka Hitoshi , Takenaka Osamu , Onitsuka Toshio , Hamada Minoru 
Published: July 2007

AbstractSite‐directed mutagenesis of human adenylate kinase (AK) was carried out on residues His36, Lys55, and the C‐terminal segment (Val182, V186, and Leu193). Five mutants (H36T, K55G, V182G, V186S, and L193Stop (deletion of residues 193‐194) were generated and analyzed by steady‐state kinetics. H36T, K55G, and L193Stop mutants showed an increase of Km values (19.8‐, 19.7‐, and 11.3‐fold) for AMP2‐ compared to that for the wild‐type enzyme, and these residues appeared to interact with AMP2‐. V182G showed an increased Km value (7.4‐fold) for MgATP2‐. Therefore, V182 may be essential for interaction with MgATP2‐. V186S increased the Km value (7.0‐ and 7.5‐fold) for MgATP2‐ and AMP2‐. V186 may thus interact with both substrates. The C‐terminal domain of AK appears to be essential for MgATP2‐ and AMP2‐ binding.
Degradation of transferrin and albumin by radical reactions in human plasma evaluated by immunoblot
Authors: Yamada Yasuko , Okamoto Eiko , Tanaka Kyoko , Kojo Shosuke 
Published: July 2007

AbstractImmunoblot analysis showed that transferrin and human serum albumin were degraded in a similar rate on the basis of the protein weight by radical reactions using a solution containing each protein initiated by Cu2+ and hydrogen peroxide. When plasma was treated with Cu2+ and hydrogen peroxide, the rate profile of the degradation of transferrin was similar to that of albumin based on immunoblot analysis in spite that the content of these proteins in plasma was considerably different. These results suggest that highly reactive hydroxyl radicals attack these proteins indiscriminately. Present observations demonstrate that immunoblot analysis is an effective method to analyze radical reactions of each protein in the presence of many other proteins like plasma.
Structural studies of cucumber mosaic virus: Fourier transform infrared spectroscopic studies
Authors: Renugopalakrishnan V. , Piazzolla P. , Tamburro A. M. , Lamba O. P. 
Published: July 2007

AbstractThe secondary structure of cucumber mosaic virus (CMV) was investigated in solution using Fourier transform infrared (FT‐IR) spectroscopy. The amide I region of intact CMV revealed a doublet at 1671 cm‐1 and 1653 cm‐1, respectively. In order to isolate the IR bands arising from the protein backbone of CMV, the FT‐IR spectra of the RNA component, isolated by phenol‐SDS treatment of purified CMV and subsequent precipation by ethanol, was obtained separately and digitally subtracted from the intact CMV spectra. After digital subtraction, the amide I region contained two bands at 1682 cm‐1 and 1644 cm‐1. The former band was ascribed to β‐sheet structures, while the later band occurs in the region between α‐helix and “unordered” structures. Resolution enhancement of the finger print amide I region was accomplished using Fourier self‐deconvolution of the digitally subtracted FT‐IR spectrum of CMV which further confirmed the presence of anti‐parallel β‐sheet structure in the protein coat of CMV. Chou‐Fasman predictions on the the coat protein also revealed the presence of β‐sheet structure in agreement with FT‐IR studies.
cDNA cloning and sequence analysis of six neurotoxin‐like proteins from Chinese continental banded krait
Authors: Qian You‐cun , Fan Chun‐yang , Gong Yi , Yang Sheng‐li 
Published: July 2007

AbstractThe cDNAs encoding six neurotoxin‐like proteins were cloned from the total RNA isolated from one venom gland of Bungarus multicinctus multicinctus by reverse transcription‐polymerase chain reaction. Although they shared a high degree of nucleotide sequence homology, the deduced proteins displayed a rather low extent of identical residues with the exception that the 21 residue signal peptides were highly conserved. Each mature protein consisted of 65, 66 or 68 amino acids with four or five disulfide bonds respectively. Comparative sequence analyses showed that they were structurally related to neurotoxin homologues. Phylogenetic analyses implied that they might represent two different evolutionary branches.
Antioxidant activity of aminoethylcysteine ketimine decarboxylated dimer on copper‐induced LDL oxidation
Authors: Matarese Rosa Marina , Macone Alberto , Fontana Mario , Duprè Silvestro , Cavallini Doriano 
Published: July 2007

AbstractAminoethylcysteine ketimine decarboxylated dimer (AECK‐DD), a member of a family of natural cyclic sulfur‐containing aminoacids, recently detected in biological samples, protects low density lipoprotein (LDL) against copper‐mediated oxidation, as assessed by monitoring the kinetics of conjugated diene formation, thiobarbiturie acid‐reactive substances production and LDL‐tryptophan fluorescence quenching. Moreover, AECK‐DD exerts a protective effect also against metal‐independent, peroxyl radical‐induced lipoprotein oxidation. It is of note that the concentrations exerting a protective effect against LDL oxidation are similar to those found in biological samples.
HMG CoA reductase inhibitor accelarates aging effect on diaphragm mitochondrial respiratory function in rats
Authors: Sugiyama Satoru 
Published: July 2007

AbstractWe examined effects of pravastatin on age‐related changes in mitochondrial function in rats. Decline in the activity of complex I of the mitochondrial electron transport chain was observed in diaphragm and psoai major in rats aged 35 and 55 weeks, and that of complex IV in rats aged 55 weeks. Pravastatin accelerated significantly age‐related decline in the activity of complex I of diaphragm mitochondria, though pravastatin did not show significant effect on normally observed age‐associated decline in the activities of complex IV of psoal major and diaphragm mitochondria. Aginng effect on mitochondrial respiratory function was not observed on heart muscle and liver in rats up to 55 weeks old, and pravastatin did not effect significantly heart and liver mitochondrial respiratory function. From these results, careful clinical examination on respiratory muscle function should be necessary in patients treated with pravastatin particularly in elderly patients.
High‐level expression of human interleukin‐17 in the yeast Pichia pastoris
Authors: Zhou Limei , Wang Jiaxi , Peng Shangyun , Duan Jubao , Cai Xin , Zou Minji , SU Qing 
Published: July 2007

AbstractHuman interleukin‐17 (hIL‐17) gene without the signal sequence was isolated from activated peripheral blood lymphocytes by RT‐PCR, then highly expressed in the yeast Pichia pastoris in the form of the glycosylated monomer. The monomer of rhIL‐17 stimulated mouse fibroblast 3T3 cells to secrete IL‐6 and was specifically bound to its receptors on 3T3 cells.
Influence of age on enzyme activities of pyrimidine metabolism in the chicken heart
Authors: Wegelin I. , Pane G. , Orlandini G. , Clò C. 
Published: July 2007

AbstractThe effect of the aging on the activities of enzymes involved in UMP‐CMP metabolism were evalued in the heart of newborn (1‐day‐old), young (20‐day‐old), adult (12‐month‐old), and aged (30‐month‐old) chickens.In newborn animals, UMP metabolism proceeds preferentially towards cytidine compounds rather than to breakdown. In addition, two pathways different from those involved in de novo synthesis may contribute to the synthesis of UMP : one, through cytosine deaminase that shows its maximal activity; the other, by uridine kinase, the main “salvage” enzyme of pyrimidine nucleotides.In young chickens, pyrimidine metabolism regards especially UMP. In fact, the lower activities of cytidylate phosphatase and cytosine deaminase, together with the remarkable increase of uridine kinase indicate that the metabolic flux converges on the main salvage pathway.In adult chickens, pyrimidine catabolism is enhanced, as supported by the maximal activity of the enzymes involved in UMP‐CMP breakdown. On the contrary, the remarkable reduction of the anabolic enzymes suggests a limited resort to the salvage pathways.Finally, in aged chickens a reduced pyrimidine catabolism and a greater utilization of the salvage pathways appear to take place, thus contributing to the maintenance of pyrimidine nucleotide pool.
The free radical‐generating function of a familial amyotrophic lateral sclerosis‐associated D90A Cu,Zn‐superoxide dismutase mutant
Authors: Kim Sung Moon , Eum Won Sik , Kwon Oh Bin , Kang Jung Hoon 
Published: July 2007

AbstractThe free radical‐generating functions of the D90A Cu,Zn‐superoxide dismutase (SOD) associated with Swedish familial amyotrophic lateral sclerosis (FALS) patients are investigated. The results show that both the wild‐type and mutant enzymes have identical dismutase activity, while the free radical‐generating activity of the D90A mutant is enhanced relative to that of the wild‐type enzyme. The studies suggest that the active channel of the D90A mutant is larger than that of the wild‐type enzyme. A higher free radical‐generating activity of the mutant enzyme led to the release of copper ions from the damaged protein. The generation of strand breaks in plasmid DNA was enhanced more effectively by the D90A mutant Cu,Zn‐SOD than by the wild‐type enzyme. The results suggest that the pathology of FALS may be attributed to oxidative damage caused by the gain‐of‐function of FALS Cu,Zn‐SOD mutant.
Characterization and cloning of long neurotoxin homolog from Naja naja atra
Authors: Lin Shinne‐ren , Huang Hsien‐bin , Wu Bin‐nan , Chang Long‐sen 
Published: July 2007

AbstractThe cDNA encoding a long neurotoxin homolog was constructed from the cellular RNA isolated fom the venom glands of Naja naja atra (Taiwan cobra) by reverse transcription‐polymerase chain reaction. BLAST searches for sequence similarity in the GeneBank databases reveal that the cDNA sequence of the long neurotoxin homolog is not highly homologous with long and short neurotoxins. Although the long neurotoxin homolog exhibited an activity to inhibit acetylcholine‐induced muscle contractions as Naja naja atra cobrotoxin, the degree of inhibition caused by the addition of long neurotoxin homolog was only approximately 35% of that observed with the addition of cobrotoxin. Moreover, the primary structure of the long neurotoxin homolog did not fulfill the characteristic features of long or short neurotoxins. Together with long neurotoxin homologs from other snake species, they probably represent an evolutionary divergence between long and short neurotoxins.
Genomic structure of the human ribosomal protein L41 gene
Authors: Go Hiroki , Miyado Kenji , Taniguchi ShuN′ichiro 
Published: July 2007

AbstractUsing PCR technique, genomic DNA encoding the gene of the human ribosomal protein L41 was amplified. Subsequent sequencing showed that the gene was constituted with 4 exons and 3 introns. Because the amplified gene contained introns and whole the open reading frame, we concluded the fragment corresponded to the functional gene.
Novel substrates of yeast alcohol dehydrogenase‐4. Allyl alcohol and ethylene glycol
Authors: Trivic Svetlana , Leskovac Vladimir 
Published: July 2007

AbstractIn the present work, we have determined the steady‐state kinetic constants for yeast alcohol dehydrogenase‐catalyzed oxidation of allyl alcohol (H2C=CH.CH2OH) and ethylene glycol (HOCH2.CH2OH) with NAD+, at pH 8.0; also, a kinetic mechanism for the former reaction was determined at the same pH. In addition, it was found that acrolein is a potent inhibitor of yeast alcohol de‐hydrogenase.
Characterization and partial purification of CD34 progenitor cell ecto‐phosphatidic acid phosphohydrolase
Authors: Harvey Kevin A. , Siddiqui Rafat A. , Reeves Margaret , Kovala Thomas , Dugan Michael , Akard Luke P. , English Denis 
Published: July 2007

AbstractPhosphatidic acid and its hydrolysis product, diacylglycerol, play potentially vital roles as extracellular messengers in numerous cellular systems and may play a key role in regulating hematopoiesis. In this study, we describe an ecto‐phosphatidic acid phosphohydrolase that potentially regulates cellular responses to phosphatidic acid on bone marrow derived human hematopoietic progenitors. We partially purified hematopoietic progenitor ecto‐PAPase using a novel in‐gel phosphatase assay and then characterized the enzyme on phenotypically defined subpopulations of hematopoietic CD34+ progenitors isolated by flow cytometry. The most pronounced PAPase activity was confined to uncommitted CD34+/CD38+ hematopoietic progenitors, which lacked the expression of other lineage‐associated antigens. We conclude that hematopoietic progenitor cells at various stages of maturation possess a potent ecto‐PAPase, an enzyme well positioned to regulate progenitor cell growth and differentiation induced by phosphatidic acid and related lipids.
Pressure effects on proteolysis catalysed by calpain
Authors: Bessiere Philippe , Bancel Frédéric , Cottin Patrick , Ducastaing André 
Published: July 2007

AbstractThe effects of pressure on μ and m‐calpain stability and specific activity have been examined. Activity and stability of these neutral calcium‐dependent heterodimeric proteinases were studied using an in‐house built bioreactor allowing on‐line spectrophotometric monitoring with retention of pressure. Both isozymes were founded to be rather baro‐sensitive with t1/2 at 1500 bar of 6 min and 11 min for μ and m‐calpain respectively. Activity measurements under pressure showed a biphasic behavior for both proteinases with a slight activation for pressure up to 500 bar and 750 bar for m and μ‐calpain respectively. Activation volume changes indicated that the proteolytic reaction was alternatively favored and disfavored by pressure due to catalytic step activation associated with enzyme‐substrate binding step being continuously inhibited by pressure. Furthermore, autoproteolysis of calpain, a calcium dependent phenomenon was inhibited by application of pressure indicating that pressure inhibition of proteolytic activity could also be due to Ca2+‐binding decrease under pressure. Implication of these results with catalytic mechanism of these heterodimeric proteinases is also discussed.
Effects of ethanol ingestion on sperm monosaccharides and fertility
Authors: Srikanth V. , Aruldhas M. M. , Srinivasan N. , Govindarajulu P. , Balasubramanian K. 
Published: July 2007

AbstractChronic alcohol abuse is often associated with reproductive disorders. Sperm monosaccharides play an indispensable role in sperm‐egg interactions and fertilization. Ethanol (3 g/kg body weight as 25%, v/v) was given by gastric intubation twice daily for 30 days while in another group, rats which had been treated with ethanol were withdrawn from treatment for a further period of 30 days, in order to assess the reversibility of the ethanol‐induced effects. Epididymal ethanol content, sperm monosaccharides and the fertility of ethanol treated and ethanol withdrawn rats were assessed. Ethanol ingestion caused a significant decrease in sperm monosaccharides suggesting defective glycosylation of sperm surface proteins. Sperm monosaccharides and fertility were returned to normal following the withdrawal of ethanol. Ethanol‐induced changes in sperm monosaccharides may be one of the reasons for the reduced fertility of ethanol treated rats.
Monoclonal antibodies against vascular endothelial growth factor 165 (VEGF165): Neutralization of biological activity and recognition of the epitope
Authors: Chen Jun‐Hui , Wang Xin‐Chang , Sato J. Denry 
Published: July 2007

AbstractFive antibodies against vascular endothelial growth factor 165 (VEGF165) were obtained. These antibodies, Ab‐2, Ab‐20, Ab‐153, Ab‐309, Ab‐342, were able to recognize not only native VEGF165, but also reducing VEGF165. Three of the antibodies, Ab‐153, Ab‐309, Ab‐342, were identified as VEGF165 neutralizing antibody on the basis of its ability to inhibit the proliferation of human umbilical vein endothelial cells (HUVEC) induced by VEGF165 and the binding of [125I]‐VEGF165 to receptors on HUVEC. The fragments of E1 (VEGF120‐135) and E2 (VEGF46‐60) recognized by neutralizing antibodies may be related the receptor binding domain of VEGF.
Cloning of a tellurite resistance determinant from Bacillus stearothermophilus V in Escherichia coli
Authors: Vásquez Claudio , Saavedra Claudia , Loyola Claudia , Moscoso Hugo , Pichuantes Sergio 
Published: July 2007

AbstractA potassium tellurite‐resistance determinant was isolated from Bacillus stearothermophilus V and cloned in Escherichia coli. Transformed cells formed black colonies when grown on solid media containing permissive tellurite concentrations. The resistance determinant was contained in a B. stearothermophilus V chromosomal DNA fragment of 7 kb.
Cloning, sequence analysis and expression in E. coli of the cDNA of the thrombin‐like enzyme (pallabin) from the venom of Agkistrodon halys pallas
Authors: Fan Chun‐Yang , Qian You‐Cun , Yang Sheng‐Li , Gong Yi 
Published: July 2007

AbstractThe cDNA of the thrombin‐like enzyme (pallabin) from the venom of Agkistrodon halys pallas was cloned and sequenced. The length of the cDNA is 923bp which includes 120bp of noncoding region and 780bp of coding region. Pallabin was synthesized as a prozymogen with 260 amino acids, which includes a signal peptide of 18 amino acids, a proposed propeptide of 6 amino acids and a matured peptide of 236 amino acids. Pallabin exhibits a strong amino acid similarity to the serine proteases isolated from other snake venoms. It contains 12 cysteins which form 6 disulfide bridges. Like other serine proteases, it also has three conserved catalytically active sites: His41, Asp86 and Ser182. To our knowledge, this study is the first report concerning the cDNA of a thrombin‐like enzyme from Agkistrodon halys pallas. The cDNA was cloned into the expression plasmid pT7ZZa and expressed in E.coli. The recombinant pallabin immunologically reacted with its specific antibody.
Effect of dietary fish oil on tumor‐induced hyperlipidemia and tumor growth in rats implanted with a methylcholanthrene‐induced sarcoma
Authors: Radcliffe J. , Narins D. Czajka , Imrhan V. , Edwards M. 
Published: July 2007

AbstractMale Fischer 344 rats implanted with a methylcholanthrene‐induced sarcoma (MCS), along with normal (or control) animals, were fed diets containing either 10% corn oil (CO) or 2% CO + 8% fish oil (FO), designated as diets CO and FO, respectively, in a study designed to determine the effect of dietary FO on serum lipids (in the presence or absence of a tumor) and the growth and fatty acid composition of the MCS. For both diets, MCS‐bearing rats had significantly (p<0.05) higher serum levels of triglycerides, cholesterol, phospholipids, and total lipids than controls. For both controls and tumor‐bearers, serum levels of all these lipids were, with the exception of cholesterol for the tumor‐bearers, significantly lower in rats receiving the FO diet than for the corresponding groups receiving the CO diet. Relative to rats fed the CO diet, those fed the FO diet had significantly higher serum levels of some fatty acids (e.g., 20:5n‐3) but significantly lower levels of others (e.g.,18:2n‐6), regardless of tumor status. For the tumor‐bearers, differences in the levels of fatty acids in MCS tissue reflected differences in the fatty acid composition of total serum lipids. Sarcoma growth was unaffected by diet. Thus, feeding dietary FO resulted in changes in the lipid status of both control and tumor‐bearing rats. Since sarcoma growth was unaffected by diet, the reduction in the severity of MCS‐induced hyperlipidemia by FO appears to be due to an effect of the oil per se.
Sedimentation analysis of muscle glycogen phosphorylase b entrapped in hydrated reversed micelles of aerosol OT in octane
Authors: Kurganov B. I. , Chebotareva N. A. 
Published: July 2007

AbstractThe oligomeric state and formation of supramolecular structures of glycogen phosphorylase b from rabbit skeletal muscles have been studied in the system of hydrated reversed micelles of aerosol OT (AOT) in octane. Sedimentation studies show that the oligomeric state of the enzyme is controlled by the degree of hydration of micelles. Monomeric, dimeric, trimeric, tetrameric, hexameric, or octameric forms of the enzyme were observed depending on the degree of micelle hydration.
Purification and characterization of a cell‐surface lectin (lectin II) from Agrobacterium radiobacter NCIM 2443
Authors: Syed F. B. F. , Joshi B. N. , SivaRaman H. , Khire J. M. , Khan M. I. 
Published: July 2007

AbstractA lectin was isolated from Agrobacterium radiobacter cell surface and purified. It is a monomer of 40 kDa as shown by SDS‐PAGE. The lectin has a pI of 9.15 and amino acid composition of the lectin shows that 44% of the amino acids are hydrophobic. The lectin agglutinates rabbit erythrocytes but does not agglutinate human erythrocytes. It does not show specificity for monosaccharides except for D‐glucosamine. Fetuin and its N‐linked glycopeptide also inhibit the activity of the lectin but greater inhibition is shown by locust bean gum and Nicotiana tobaccum (tobacco) tissue extracts.