bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of chlorella T‐1 ingredient which enhances DMPO‐OH adduct formation in fenton reaction
Authors: Ali M. Aktar , Oykawa Kikuo , Ohwada Minoru , Konishi Tetsuya 
Published: July 2007

AbstractChlorella T‐1 is a micro algae which carries out highly active photosynthetic carbon fixation. For searching the ·OH scavenging molecules in this strain, the methanol extract of T‐1 was fractionated by RP‐HPLC and the fractions were analyzed for DMPO‐OH formation by ESR after Fenton reaction. In the course of study, a single chlorella T‐1 ingredient was found to enhance the formation of DMPO‐OH rather than scavenge in the Fenton system. The ·OH enhancing chlorella component was further purified by chromatography and finally identified as lactic acid by NMR and LC‐MS. From the analysis of the reaction conditions for DMPO‐OH, it was found that lactic acid did not serve as direct source of ·OH but accelerated Fenton reaction.
Involvement of the GLUT 3 transporter in myogenic regulation
Authors: Broydell M. , Mazzuca D. M. , Abidi F. , Kudo P. A. , Lo T. C. Y. 
Published: July 2007

AbstractWe have recently demonstrated a close relationship between the GLUT 3 transporter and the myogenic ability of rat skeletal L6 myoblasts [1]. This investigation examined the effects of over‐and under‐expression of the GLUT 3 transporter on both biochemical and morphological differentiation. L6 transfectants expressing two to five times the normal L6 GLUT 3 transcript level were impaired in the expression of myogenesis‐associated genes, such as myogenin, MLC, MHC and TnT, and in myotube formation. Similar defects were also observed in myoblast mutants expressing less than 20% of the normal GLUT 3 level. Forced expression of an exogenous GLUT 3 cDNA could partially rescue the myogenic defect of these GLUT 3‐ mutants. However, such myogenic defects were not observed in L6 GLUT 3 antisense transfectants expressing 39% of the normal L6 GLUT 3 level. These data suggest that myogenic differentiation will proceed only within a critical level of the GLUT 3 transporter. The optimal GLUT 3 content for myogenesis ranges from around 2 × 105 to 5 × 105 molecules per cell in day 2 cultures; GLUT 3 levels outside this range have a negative effect on myogenesis. Our data suggest that GLUT 3 may regulate myogenesis by modulating the levels of signal transducers required for expression of myogenin and muscle‐specific contractile protein genes.
Occurrence of two missense mutations in Cu‐ATPase of the macular mouse, a menkes disease model
Authors: Ohta Yuriko , Shiraishi Noriyuki , Nishikimi Morimitsu 
Published: July 2007

AbstractWe have investigated the genetic defect of the Cu‐ATPase gene (Atp7a) in the macular mouse, a genetic model of classical Menkes disease. Northern blot analysis showed that its placenta and kidney possess a normal amount of the Cu‐ATPase mRNA of the normal size; sequencing analysis revealed two missense mutations, His674Arg and Ser1381Pro, in a PCR‐amplified cDNA for mutant Cu‐ATPase. The latter mutation was suspected to affect the function of the ATPase, because it lies in the transmembrane segment that is thought to form a channel for the transportation of copper ions.
Intracellular proteases in sporulated Bacillus thuringiensis subsp. tenebrionis: detection and analysis by gelatin zymography
Authors: Reddy Sreelatha T. , Venkateswerlu G. 
Published: July 2007

AbstractThree intracellular proteases were identified from sporulated cultures of Bacillus thuringiensis subsp. tenebrionis by fractionation with ammonium sulfate. In this study, we detected protease activities at Mr 92 kDa, 81 kDa and 69 kDa employing gelatin zymography. The major proteolytic activity was due to the 81 kDa protease, which was identified as a metalloprotease being inhibited by both 1,10‐phenanthroline and ethylenediamine tetraacetic acid. The proteases showed maximal azocasein hydrolytic activity at 60°C and were heat‐activated from 40°C to 60°C. The 69 kDa and 81 kDa proteases were thermo‐inactivated at 70°C and 80°C respectively, while the 92 kDa protease was still active at 80°C.
Effect of pyrrolidine dithiocarbamate on photo‐induced proton transport through chloroplast membranes
Authors: Po Edwina Sau‐Man , Ho John W. 
Published: July 2007

AbstractpH changes produced by photo‐induced proton transport through chloroplast membranes in spinach were measured by a glass microelectrode. Effect of pyrrolidine dithiocarbamate on proton translocation through chloroplast membranes has been studied. Kinetic analysis of proton translocation shows that the rate is reduced as the carbamate concentration increases. The rate of proton uptake follows firstorder kinetics and diminishes with increasing carbamate concentrations. The outward leakage of accumulated protons through thytakoid membranes in the dark also decreases likewise. However, the leakage of protons takes a much longer time. Pyrrolidine dithiocarbamate is an effective inhibitor of proton transport through chloroplast membranes. The results suggest that the photo‐induced proton translocation is regulated by conformation change in the membrane. Higher concentration of carbamate disrupts the tertiary conformation of the membrane. The inhibition of proton transport would affect ATPase function; thus, an excess use or accumulation of pyrrolidine thiocarbamate may compromise ATP production.
A new family of plasma membrane polypeptides differentially regulated during plant development
Authors: Logan David C. , Domergue Odile , de la Serve Bernard Teyssendier , Rossignol Michel 
Published: July 2007

AbstractTwo cDNAs encoding polypeptides identified in a tobacco leaf plasma membrane fraction prepared by phase partitioning were cloned. The deduced polypeptides, P16 and P17, exhibit a striking primary structure, similar to that of P19, a previously cloned plasma membrane polypeptide. Antibodies raised to the recombinant proteins were used to probe the cellular location of P16, P17 and P19 by means of western blotting of sucrose density‐gradient fractions; all three polypeptides were found to be located solely at the plasma membrane. Furthermore, P19 antigen accumulated transiently at the time of floral induction while P16 and P17 antigens accumulated towards the end of the life‐cycle. These results together with sequence database searches and multiple‐sequence alignments suggest that we have identified a new family of plasma membrane polypeptides that (i) are putatively plant specific and (ii) are differentially regulated during plant development. These polypeptides are termed DREPPs for developmentally regulated plasma membrane polypeptides.
Inhibition of proteases, myotoxins and phospholipases A2 from Bothrops venoms by the heteromeric protein complex of Didelphis albiventris opossum serum
Authors: Soares A. M. , Rodrigues V. M. , Borges M. H. , Andrião‐Escarso S. H. , Cunha O. A. B. , Homsi‐Brandeburgo M. I. , Giglio J. R. 
Published: July 2007

AbstractThe antibothropic complex (ABC) from opossum (species Didelphis albiventris) serum was purified by chromatography on DEAE‐Sephacel. It showed an acidic character and two polypeptide chains of ca. 45 kDa and 48 kDa, respectively. Lyophilized opossum serum or the ABC (1001μg), as well as ethylenediamine tetraacetate (0.25μmotes) were able to completely neutralise the hemorrhagic effect of 50μg of the desiccated venoms of Bothrops moojeni, Bothrops pirajai and Bothrops jararacussu. The myotoxic (100μg venom in mice) and edematogenic (90μg venom in rats) activities of Bothrops moojeni and Bothrops jararacussu venoms, as well as of the major myonecrotic protein (myotoxin‐I) isolated from Bothrops moojeni venom, were also totally inhibited by the ABC (200μg and 270μg, respectively). The lyophilized opossum serum (30μg) and the ABC (30μg) reduced to 50% the phospholipase A2 activity of Bothrops moojeni venom (10μg). The clotting activity of Bothrops alternatus and Bothrops moojeni (20μg) on bovine plasma was also significantly inhibited by the ABC (60μg).
The differential transforming activities of TAL1 oncoproteins
Authors: Hsu Shih‐Fang , Cheng Jiin‐Tsuey 
Published: July 2007

AbstractTAL1 (Or SCL) oncogene produces both full‐length pp42 and truncated pp22 phosphoproteins in T‐cell acute lymphoblastic leukemia cells. To investigate the transforming properties of these two oncoproteins, permanent transfected NIH3T3 cell lines were generated that constitutively express either pp42 or pp22. Both cell lines exhibited similar morphology as parental NIH3T3 cells. However, they showed differential anchorage independent growth in soft‐agar. The clonogenicity of pp22 expressing cells was ten folds higher than that of pp42 expressing cells. This result might implicate the differential transformation potential of the two Tal1 oncoproteins.
Single microinjection of L‐glutamate induces oxidative stress in discrete regions of rat brain
Authors: Babu G. Nagesh , Bawari Meenakshi 
Published: July 2007

AbstractGlutamate (Glu) is a major excitatory aminoacid neurotransmitter in the mammalian brain. Under Certain Circumstances Glu can also exert toxic effects on neuronal Cells. To unravel the biochemical mechanisms of Glu‐induced acute neuronal injury, Glu 1μmol/1μl was microinjected into cerebral Cortex, striatum and hippocampus of adult rats and oxidative stress and antioxidant parameters were evaluated. The results show that the rate of lipid peroxidation was significantly increased in the above brain regions following Glu administration suggesting neuronal membrane damage and also the total and free sulfhydryl groups were significantly depleted, indicating altered red‐ox status of the cells. There was also alteration in the activity of antioxidant enzyme catalase in cerebral cortex. Some of the above Glu‐induced effects were reversed or modified by NMDA receptor antagonist MK‐801.
RAPD analysis of Candida albicans strains recovered from different immunocompromised patients (ICP) reveals an apparently non‐random infectivity of the strains
Authors: Gyanchandani Anita , Khan Zafar K. , Farooqui Nuzhat , Goswami Mamta , Ranade Shirish A. 
Published: July 2007

AbstractThe opportunistic imperfect fungus Candida albicans causing life‐threatening infections in immunocompromised patients (ICP), especially in HIV‐positive cases, is recognized to be one of the most important nosocomial pathogens in the recent decades. The extent of strain‐to‐strain variation within a species and its relationship to the ability of the organism to colonize or invade a specific group of patients or even a body site is, however, not well known. We have analysed 19 strains of C.albicans recovered from ICP at different locales and times, employing the RAPD technique. No two strains generated identical RAPD profiles with any of the 21 primers tested. Further, the UPGMA clustering of the strains seemingly reflected a certain relationship or non‐randomness in the infection of the patients with the strain of C.albicans vis‐a‐vis the immunocompromised status due to underlying disease such as diabetes, cancer, asthma and meningitis. These results may have a profound impact on the management of candidiasis, especially in the ICP.
Conformation of polygalacturonase‐II from Aspergillus carbonarius ‐ A spectroscopic study
Authors: Devi Nemkal Anjana , Rao A.G. Appu 
Published: July 2007

AbstractSolution conformation of polygalacturonase from Aspergillus carbonarius was determined by spectroscopy. UV absorption, second derivative, near‐UV CD, fluorescence emission spectra and fluorescence quenching measurements suggest that the tryptophan fluorophores are in a hydrophobic environment. Of the nine tryptophan residues, only one is exposed to the solvent. In the near UV region the enzyme exhibits very weak CD bands, the far UV CD spectrum has a minimum at 218 nm; the enzyme is rich in parallel β structure. Modification of solvent exposed tryptophan by N‐bromosuccinimide resulted in the complete loss of enzyme activity. The enzyme is very sensitive towards urea induced unfolding, with complete loss of activity at 3 M urea concentration.
Is the glutathione S‐conjugate pump a flippase?
Authors: Sokal Adam , Pułaski Łukasz , Rychlik Błazej , Fortuniak Anna , Bartosz Grzegorz 
Published: July 2007

AbstractA hypothesis of the flippase nature of the glutathione S‐conjugate transport is presented. Experimental premises for this hypothesis include interaction of glutathione S‐conjugates with the membrane, as demonstrated by their effects on membrane fluidity, quenching of 1‐(4‐trimethylammoniumphenyl)‐6‐phenyl‐1,3,5‐hexatriene fluorescence and induction of echinocytosis by 2,4‐dinitrophenyl‐S‐glutathione (DNP‐SG). This hypothesis can rationalize, i. a., observations of the enhancement of DNP‐SG transport by butanol and stimulation of erythrocyte membrane Mg2+‐ATPase activity by albumin‐coupled DNP‐SG.
Fru 2,6‐P2 and citrate: Intracellular distribution in citrus tissues and effect on grapefruit leaf PFP.
Authors: Van Praag Esther , Gonzalez Pedro , Brune Andreas , Goren Raphael , Zehavi Uri , Echeverria Ed 
Published: July 2007

AbstractGrapefruit leaf PFP was studied for its activation by fructose 2,6‐bisphosphate (Fru 2,6‐P2) in the forward and reverse reactions. In the glycolytic reaction, a Ka of 4.0±0.12 nM was obtained. This constant is affected by the presence of increasing concentrations of citrate (1, 5 and 20 mM) with a Ka(citrate) of 4.5±0.09, 6.9±0.05 and 38.2±1.4 respectively. The inhibition mode of citrate is competitive with Fru 2,6‐P2, but non‐linear in relation of increasing concentrations of the inhibitor. The intracellular distribution and concentration of the key regulatory metabolite Fru 2,6‐P2 was further investigated in citrus leaves and juice cells. Fru 2,6‐P2 was only found in the cytosol of juice cells. Fru 2,6‐P2 was detected under both conditions with higher concentrations found under aerobiosis.
Non‐synergistic interactions between strong allosteric effectors and human embryonic and adult haemoglobins
Authors: McLennan Amy. E. M. , Brittain Thomas 
Published: July 2007

AbstractThe binding of two strong allosteric effectors (2,3 Diphosphoglycerate D.P.G., and Bezafibrate, Bzf) to both adult and the three human embryonic haemoglobins, either individually or in combination, have been studied in detail. The adult protein exhibits one binding site for D.P.G and two for Bzf. When both effectors are present simultaneously their effects are simply additive. The same qualitative pattern of binding is observed in the case of the three human embryonic haemoglobins, although with different binding constants. The lack of synergism between these effectors and the different binding affinity expressed by these proteins are discussed in terms of the known amino acid sequence differences.
Carnitine palmitoyltransferase II activity is decreased in liver mitochondria of cachectic rats bearing the Walker 256 carcinosarcoma: Effect of indomethacin treatment
Authors: Seelaender Maríla C. L. , Curi Rui , Colquhoun Alison , Williams John F. , Zammitt Victor A. 
Published: July 2007

AbstractThe syndrome of cancer cachexia is accompanied by several alterations of lipid metabolism, especially that in the liver. In this study we have investigated a possible mechanism whereby the presence of the Walker 256 carcinosarcoma affects hepatic fatty acid oxidative capacity in tumour‐bearing rats. Hepatic mitochondrial outer membrane carnitine palmitoyltransferase I (CPT I), generally accepted as the main site of regulation of fatty acid oxidation, was unaffected by the presence of the extra‐hepatic tumour. However, mitochondrial inner‐membrane carnitine palmitoyltransferase II (CPT II) activity was markedly decreased in mitochondria isolated from the liver of tumour‐bearing rats. Immuno‐detection by Western blotting using a CPT II‐specific antibody identified two bands (corresponding to Mr 69,000 and 54,000) in tumour‐bearing rats whereas only the normal‐sized CPT II was present (at the expected Mr 69,000) in mitochondria from control rats. It is suggested that the emergence of the second, smaller protein may represent a catalytically less active protein that arises in vivo, since its appearance was not affected by the inclusion of proteolysis inhibitors in the mitochondrial preparation buffers. Treatment of the tumour‐bearing rats with indomethacin, a prostaglandin (including PGE2) synthesis inhibitor, increased CPT II activity to levels even higher than those found in the control animals. It is suggested that PGE2 may play a role in the control of CPT II expression in the liver of tumour‐bearing rats. Indomethacin treatment did not affect either of the two CPT activities of the mitochondria isolated from tumour tissue.
D‐myo‐inositol derivatives alter liposomal membrane fluidity
Authors: Brailoiu Eugen , Margineanu Anca , Toma Catalin P. , Filipeanu Catalin M. , Rusu Valeriu , Branisteanu Dimitrie D. 
Published: July 2007

AbstractWe investigated the effect on membrane fluidity induced by D‐myo‐inositol derivatives (IP3, IP4, IP5, IP6). Fluidity was determined as the anisotropy of fluorescence polarisation from liposome model membranes labelled with DPH (1,6‐diphenyl‐1,3,5 hexatriene). IP3 (10‐10 to 10‐5 M) increased the membrane fluidity with a maximum effect at 10‐5 M. For IP4, IP5 and IP6, at concentrations less than 10‐6 M these derivatives increased the membrane viscosity (i.e. reduced fluidity). This effect was enhanced when the derivatives were incorporated in the vesicles, rather than added to the vesicle suspension. In this case IP5 and IP6 increased viscosity over the reference values. We conclude that inositol derivatives directly modified membrane fluidity which could play a role in their effects in biological systems, beside the one mediated by binding to specific receptors.
Lithium regulation of protein phosphorylation in rat cerebral cortex slices in vitro
Authors: Singh Tryambak Deo , Shankar Raj 
Published: July 2007

AbstractThe aim of the present study was to evaluate the direct effect of Li+ and Na+‐Li+ exchange on protein phosphorylation in rat cerebral cortex slices incubated in Krebs Ringer medium. When Na+ concentration was varied in the incubation medium, either by replacement with Li+ or sucrose, a variable effect on [32P] phosphate incorporation into proteins was observed. Protein phosphorylation in cerebral cortex slices was very low in the absence of Na+, and some dependence of phosphorylating system of neural tissue on extra cellular concentration of Na+ was evident. Lithium was not able to replace sodium as far as protein phosphorylation in cortical slices is concerned. Ouabain was more effective in a Li+ containing medium in inhibiting protein phosphorylation, presumably due to improper functioning of the sodium pump.
Ascorbate peroxidase and catalase cooperate for protection against hydrogen peroxide generated in potato tubers during low‐temperature storage
Authors: Mizuno Masashi , Kamei Michiyo , Tsuchida Hironobu 
Published: July 2007

AbstractWe investigated the behavior of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APx), in potato tubers during storage at low temperature. SOD activity increased temporarily within 3 weeks and was higher at 1°C than at 20°C. APx activity also increased more at low (1°C) than at higher temperatures (5 and 20°C). The contents of ascorbic acid (AsA), which is the substrate of APx, decreased immediately within 3 weeks and then gradually decreased until 15 weeks. The activity of CAT, the other enzyme which can scavenge hydrogen peroxide, decreased once in the first six weeks and thereafter increased to 15 weeks. Thus, the enhancement of the active oxygen‐scavenging system that was induced by low temperature in potato tubers could result not only in a decrease of AsA but also in combined increases in APx and CAT activity whose manners were different.
Structural characterization of human glyoxalase II as probed by limited proteolysis
Authors: Aceto Antonio , Dragani Beatrice , Melino Sonia , Petruzzelli Raffaele , Gualtieri Gabriella , Principato Giovanni , Saccucci Franca 
Published: July 2007

AbstractHuman glyoxalase II is partially proteolyzed by trypsin, under non denaturing conditions, only at the level of the C‐terminal region. The proteolytic cleavage resulted in an inactivation of the enzyme without loss of the secondary structure. Sodium dodecyl sulphate polyacrylamide gel‐electrophoresis and microsequence analysis showed that the glyoxalase II is proteolyzed at the level of Arg 184 and Lys 230 and undergoes a third cleavage in a region located at the beginning of the supposed C‐terminal domain. The proteolysis occurs either in the presence or in the absence of specific inhibitors. Our limited proteolysis experiments and secondary structure prediction give evidence for the presence of two domains characterized by different pattern of secondary structure.
Aquaporin 3 is induced in rat alveolar epithelium after birth
Authors: Koyama Nobuyuki , Inase Naohiko , Tanaka Michiko , Ichioka Masahiko , Sasaki Sei , Marumo Fumiaki 
Published: July 2007

AbstractAquaporin (AQP) is the water channel protein associated with water‐permeability, in which AQP1, AQP3, AQP4, and AQP5, are expressed in respiratory organs. Because water filling the fetal lung has to be absorbed after birth, aquaporins are postulated to contribute to this water reabsorption. To examine the potential role of AQP3 around birth, we studied mRNA expression and localization of AQP3 in fetal and postnatal rat lung. AQP3 mRNA was most prominently expressed in rat lung on the day of birth, began to decrease on the 2nd day after birth, and was not observed on the 4th day and later. In situ hybridization demonstrated that AQP3 mRNA was expressed in alveolar epithelium. The expression of AQP3 mRNA may influence water reabsorption of the perinatal rat lung.
Identification by bacterial expression of the yeast genomic sequence encoding L‐galactono‐γ‐lactone oxidase, the homologue of L‐ascorbic acid‐synthesizing enzyme of higher animals
Authors: Nishikimi Morimitsu , Ohta Yuriko , Ishikawa Takahiro 
Published: July 2007

AbstractBaker's yeast possesses L‐galactono‐γ‐lactone oxidase that is similar in enzymic properties to L‐gulono‐γ‐lactone oxidase, the terminal enzyme of L‐ascorbic acid biosynthesis in higher animals. Computer‐assisted comparison of amino acid sequences revealed the occurrence of a homologue of rat L‐gulono‐γ‐lactone oxidase in the database of the proteins encoded by the Saccharomyces genome. The gene encoding the homologue was amplified by polymerase chain reaction and expressed as a fusion protein with glutathione S‐transferase in Escherichia coli cells with expression vector pGEX‐5X‐3. The expressed protein was found to show L‐galactono‐γ‐lactone oxidase activity and also to have covalently bound flavin, as is the case with purified L‐galactono‐γ‐lactone oxidase. Thus the gene for this enzyme was unequivocally identified.
The role of counterions in the interaction of bifunctional surface active compounds with model membranes
Authors: Sarapuk J. , Kleszczynska H. , Rózycka‐Roszak B. 
Published: July 2007

AbstractInteraction of two series of bifunctional surfactants (bromides and chlorides) with red blood cells and planar lipid membranes was studied. The aim of the work was to determine the role of counterions in the mechanism of interaction of bifunctional cationic surfactants with model membranes. In each case bromides influenced model membranes to a greater degree than the corresponding chlorides. The possible explanation of the obtained results is presented. It seems that the greater ability of bromides to destabilize model membranes in comparison with chlorides can be attributed to the greater mobility and the smaller radius of the hydrated bromide ion. This may underlie the greater ease that this anion can modify the surface potential of the lipid bilayer, thus enhancing the interaction of the cationic surfactant with such a modified bilayer.