bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ursodeoxycholate promotes protein phosphorylation in the cytosol of rat hepatocytes
Authors: Capuano Ferdinando , Barone Michele , D'Eri Nicola , Russo Elisabetta , Varone Davide , Francavilla Antonio , Papa Sergio 
Published: July 2007

AbstractA study is presented of the effect of the bile salt ursodeoxycholate (UDC) on protein phosphorylation by [γ‐32P]ATP in the cytosol from ra hepatocytes. Gel electrophoresis and corresponding autoradiograms of cytosolic proteins show that UDC promotes phosphorylation of at least eight different protein bands. Four of them (the 36, 60, 64 and 76 kDa) are phosphorylated by Ca2+ and phospholipid‐dependent protein kinase (PKC); three (the 31, 51 and 71 kDa) are phosphorylated by cAMP‐dependent protein kinase (PKA) and one protein band, with molecular weight of 34 kDa, apparently contains substrates of both PKC and PKA. Data are reported indicating that UDC can directly affect the intrinsic activity of protein kinases.
The Presence of A manganese‐rich particle in lysosome of rat pancreas due to excess manganese treatment
Authors: Okamoto Yoshihiro , Oshima Reiko , Inagaki Kazuhiro , Aita Saburo , Nisioka Hideo , Kondo Yumi , Ishizuka Hiroshi , Takada Jitsuya , Nishida Mikio 
Published: July 2007

AbstractManganese (Mn) accumulates at a higher level in the pancreas than in any other organs when excess Mn is administered to the rat. The present study is carded out to analyze the intracellular localization of Mn existed in the pancreatic cell of Mn‐treated rats. Transmission electron microscope and X‐ray micro‐analysis connected with a rapid freezing fixation technique showed that a large amount of Mn was localized in tysosomal particles of the pancreatic cell of Mn‐treated rats. The Mn‐rich particles disappeared when the element‐administration was discontinued, showing that the accumulation of Mn is reversible. To confirm that Mn is in the lysosomes, a centrifugal subcellular‐fractionation and a neutron activation analysis were carried out. The result indicated that much Mn existed in the lysosomal fraction.
Characterization of phosphate transport in Strephtomyces granaticor
Authors: Lichá I. , Beneš I. , Janda S. , Hošt′álek Z. , Janáček K. 
Published: July 2007

AbstractTransport of inorganic phosphate in Streptomyces granaticolor was characterized in two growth stages; kinetic parameters were determined and two transport systems were found in both stages, with the following values: KT1=0.06 mM, Jlim1=0.95 nmo1 min‐1 (mg DS) ‐l, and KT2=1.80 mM, Jlim2= 25 nmol min‐1 (mg DS)‐1. Both systems require metabolic energy and substrates, such as sugars or polyols; when alanine was used or the energy source was omitted, the kinetic parameters changed in both systems. Both systems were inhibited by the ionophore CCCP with identical Ki. KCN, an inhibitor of terminal cytochrome oxidase, inhibited the uptake of phosphate only partially, the uptake was inhibited completely when also the inhibitor of the alternative oxidative pathway (salicylhydroxamic acid) was added. Antimycin A inhibited the uptake completely. Arsenate inhibited competitively.
Properties of Thermus aquaticus β‐NADH oxidase immobilised on various supports
Authors: Sanjust Enrico , Curreli Nicoletta , Rescigno Antonio , Bannister Joe V. , Cocco Dina 
Published: July 2007

Abstractβ‐NADH oxidase purified from Thermus aquaticus was covalently immobilised on various solid supports. The preparations obtained were compared with the soluble enzyme for activity and kinetic properties. Activated glutaryl‐PVA was found to be the best support. The immobilised enzyme was less stable at high temperatures than the soluble enzyme. No differences could be detected in the presence of organic solvents.
Molecular cloning of the leub genes from Mycobacterium bovis BCG and Mycobacterium tuberculosis
Authors: Han Mi Young , Son Mi Young , Lee Seung‐Hwan , Kim Jin Koo , Huh Jae Suk , Kim Jeong Hyun , Choe In Seong , Chung Tai Wha , Choe Yong‐Kyung 
Published: July 2007

AbstractA gene responsible for the biosynthesis of leucine has been cloned by the complementation of the Escherichia coli leuB6 auxotroph mutant after transformation with the Mycobacterium bovis BCG genomic DNA library, which was constructed by ligating the partially digested BCG DNA with Sau3AI into the pUC 19 digested with BamHI. Sequencing of the leuB gene of BCG revealed an ORF (open reading frame) of 1,011 bp encoding isopropytmalate dehydrogenase with a calculated molecular weight of 42 kDa. The leuB gene of Mycobacterium tuberculosis isolated from Korean tuberculosis patient is shown to be identical to that of BCG except one bp.
Intracellular calcium variation in heparin‐capacitated bovine sperm
Authors: Córdoba Mariana , Santa‐Coloma Tomás A. , Beorlegui Norma B. , Beconi Martha T. 
Published: July 2007

AbstractThis report investigates the mechanisms by which heparin induces capacitation of sperm. Capacitation was determined with chlortetracycline and intracellular calcium concentration, [Ca2+]i, with FURA 2‐AM. Atter 15 minutes incubation with heparin, [Ca2+]i was increased 60% over basal, reaching a plateau thereafter. Sixty percent of calcium entry was inhibited by methoxy‐verapamil, suggesting that activation of voltage dependent calcium channels (VDCC) may be involved in the process. A significant correlation (R2 = 0.88, p<0.006) was found between the percentage of capacitated spermatozoa and the [Ca2+]i increase. The effects of heparin on both processes were blocked by the protein kinase C (PKC) inhibitors staurosporine (100%) and GF‐109203X (90%). It is concluded that heparin may induce sperm capacitation and calcium influx mainly through VDCC (approx. 60%), and also through other membrane systems (40%). Both systems of calcium entry as well as the capacitation process appear to involve on PKC activity.
Carbohydrate handling in the hind leg muscle of exercising rats
Authors: Adán C. , Ardévol A. , Remesar X. , Alemany M. , Fernández‐López J. ‐A. 
Published: July 2007

AbstractThe arterio‐venous concentrations of oxygen, glucose and lactate, as well as blood flow and muscle levels of lactate, glucose, hexose‐phosphates and glycogen of rat hind leg muscle were determined under basal conditions and under mild and intense exercise, as well as during post‐exercice recovery. During intense exercise and fatigue glycogen is practically exhausted, providing glycosyl residues to the hexose‐phosphates pool in addition to increased glucose uptake from the blood. The result is the production of huge amounts of lactate, which accumulates in muscle and the skin, and buildup the arterial concentrations. During recovery lactate is slowly disposed of, and the muscle takes up large amounts of glucose which is stored into glycogen, with fully reinstated glucose oxidation. The data shown suggest that the shift from oxidative to mainly anaerobic utilization of glucose is not as streamlined as is usually assumed, since the results found here hint at the wasteful utilization of glycogen‐derived hexose skeletons for other synthetic pathways. Glucose, nevertheless, is of paramount importance as energy staple to sustain untrained intense exercise in the rat
Molecular cloning and analysis of a HSP (heat shock protein) ‐ Like 42 kDa antigen gene of Mycoplasma hyopneumoniae
Authors: Chou Shih‐Yu , Chung Tung‐Liang , Chen Re‐Jen , Ro Lee‐Hwa , Tsui Pei‐I , Shiuan David 
Published: July 2007

AbstractThe recombinant clone expressing the 42 kDa protein (P42) of Mycoplasma hyopneumoniae in Escherichia coli was analyzed. The 4.4 kb HindIII‐XmaI DNA fragment expressing the p42 gene product encodes three ORFs: p42 and pl6 in the forwarding strand, p24 in the reverse strand. Sequence comparisons revealed that p42 could be part of a p65 gene, and has 62% identities with Mycoplasma genitalium HSP70 gene and 56% identities with Bacillus subtilis dnaK gene; p16 and p24 genes share 73% and 47% identities with Erysipelothrix rhusiopathiae dnaJ gene and Pseudomonas fluorescens uvrC gene, respectively. Further analysis demonstrated that P42 is indeed a heat shock protein and the monospecific antibodies against P42 can block the growth of Mycoplasma hyopneumoniae.
Protease triggers dephosphorylation of cdc2 kinase during starfish oocyte maturation
Authors: Sawada Hitoshi , Yokoyama Kuniko , Morinaga Chikako , Yokosawa Hideyoshi , Sawada Michiko Takagi 
Published: July 2007

AbstractWe previously presented evidence that a Z‐Phe‐Ser‐argininal‐susceptible protease which is involved in oocyte maturation of the starfish, Asterina pectinifera is the proteasome (Takagi Sawada et al., Dev. Biol. 150, 414‐418 (1992)). In the present study, we investigated the timing of the function of and the role of the protease in oocyte maturation using Z‐Phe‐Ser‐argininal. By adding the inhibitor in maturing oocytes at various times after 1‐methyladenine treatment, the inhibitory ability was markedly reduced in half the time required for germinal vesicle breakdown. Furthermore, the inhibitor potently blocked the activation of histone H 1 kinase and the dephosphorylation of cdc2 kinase during oocyte maturation. These results indicate that the Z‐Phe‐Ser‐argininal‐susceptible protease, probably the proteasome, plays a key role in the step of the signal transduction pathway that triggers the dephosphorylation of cdc2 kinase in response to the maturation‐inducing hormone.
Effect of long time storage on cytosolic glutathione S‐transferases
Authors: Peters Wilbert H. M. , Roelofs Hennie M. J. 
Published: July 2007

AbstractGlutathione S‐transferases are a family of enzymes catalyzing the conjugation of glutathione to a wide variety of compounds. Stability of human liver cytosolic glutathione S‐transferase enzyme activity and levels of glutathione S‐transferase class Alpha and Mu were assessed. Cytosolic fractions of sixteen different patients were stored up to two years at three different temperatures: ‐20°, ‐80° and ‐196° Celsius. Samples were assayed for glutathione S‐transferase enzyme activity and glutathione S‐transferase class Alpha and Mu levels, after 3, 6, 12 and 24 months of storage.No significant differences in glutathione S‐transferase enzyme activity as well as in isoenzyme levels were found during this 24 months of storage at the three different temperatures. It is concluded that stability of glutathione S‐transferases allows long term storage even at ‐20°C, without significant loss of enzyme activity or enzyme protein.
Effect of cyclins and Cdks on the cyclin B1 promoter activation
Authors: Moro A. , Zerfass K. , Joswig S. , Jansen‐Duerr P. 
Published: July 2007

AbstractTo study the effect of several cyclins on cyclin B1 promoter activation, we co‐transfected cyclin A, cyclin E and cyclin D1 expressing plasmids with a cyclin B1 promoter construction driving a luciferase repotnter gene into NIH 3T3 cells. All three cyclins produced activation of the reporter gene, however, co‐transfection of cyclin A with a Cdk2 dominant negative mutant blocks activation by cyclin A. Our results suggest that cyclin B1 activation depends on Cdk2 kinase activity associated to cyclin A. To our knowledge this is the first report showing positive effect of cyclin A, cyclin E and cyclin D1 on cyclin B1 activation and blocking of this activation by a Cdk2 dominant negative mutant.
Purification and characterisation of the soluble glutathione S‐transferase isoenzymes in rat kidney derived NRK cells
Authors: Dierickx Paul J. , Noble Elisabeth 
Published: July 2007

AbstractGlutathione S‐transferase (GST) enzymes are toxicologically important from many points of view. Rat kidney derived established NRK cells were mass cultured for the isolation of GST isoenzymes. These were enriched by affinity chromatography and separated by chromatofocusing and HPLC. Exactly the same major GST subunits were found in NRK cells as in the rat kidney. Strong evidence was also found for the presence of an aberrant form of GST 7‐7, as was described in rat kidney. A very good correlation between the NRK GST and rat kidney, and especially cis‐platinum treated kidney, was found. It is concluded that NRK cells can be considered as a valuable alternative tool for in vitro research of rat kidney phenomena, especially when toxicological interactions are investigated.
Refolding kinetics of partially reduced and S‐carboxymethylated trypsin‐subtilisin inhibitor from marine turtle eggwhite
Authors: Chaudhuri Tapan K. 
Published: July 2007

AbstractThree accessible disulphide bonds of basic trypsin‐subtilisin inhibitor from marine turtle eggwhite have been reduced with 0.1M NaBH4 at 0°C under nitrogen atmosphere at pH9.8 and then S‐carboxymethylated. The partially reduced inhibitor retains 80% of the native inhibitory activity towards trypsin and subtilisin. The S‐carboxymethylated inhibitor undergoes slower refolding than the native inhibitor from its fully denatured and reduced state at pH 8.5 in the presence of oxidised and reduced glutathione. The refolding process was characterised by the attainment of the inhibitory activity towards trypsin and subtilisin. The values of the second order rate constant for the refolding reactions of the modified protein are 0.02×102M‐1sec1 and 0.033×102M‐1sec‐1 for its trpsin and subtilisin inhibiting domains and their energies of activation are 20.1 Kcal/mole and 24.6 Kcal/mole. The partially modified inhibitor does not regain complete inhibitory activity even after long incubation in the oxido‐shuffiing buffer. From the above findings it can be concluded that the three disulphide bonds of the native inhibitor are not essential for the inhibitory activity of the trypsinsubtilisin inhibitor but they help in the correct refolding of the inhibitor by forming transient disulphide bonds with the external disulphide reagents as well as with the internal sulphydryl groups.
Complete sequence of the upp gene encoding uracil phosphoribosyltransferase from Mycobacterium bovis BCG
Authors: Kim Jin Koo , Kim Jeong Hyun , Lee Seung‐Hwan , Kang Young , Lim Jong‐Seok , Lee Hee Gu , Kim Sang Jae , Bai Gill Han , Park Young Kil , Cho Sang‐Hyun , Kang Sang Won , Kim Yu Sam , Choe In Seong , Chung Tai Wha , Park Sue‐Nie , Kim Seung Ho , Ahn Jong Seog , Choe Yong‐Kyung 
Published: July 2007

AbstractThe nucleotide sequence of a 799 bp fragment of Mycobacterium bovis BCG containing the putative upp genc that encodes a uracil phosphoribosyltransferase (UPRTase [EC 2.4.2.9]) has been determined. The upp gene of BCG has an open reading frame (ORF) of 621 bp (207 amino acids) starting with GTG (position 112) and ending with TGA (position 733), and its molecular mass was calculated to be 21,864 Da. Comparative analyses of the deduced amino acid sequence of BCG UPRTasc with the UPRTase of six bacterial genera revealed that 24% (50/211) of the residues are perfectly conserved and 32% (67/211) of the residues arc well conserved.
Differences in aldehyde oxidase activity in cytosolic preparations of human and monkey liver
Authors: Sugihara Kazumi , Kitamura Shigeyuki , Tatsumi Kiyoshi , Asahara Toshimasa , Dohi Kiyohiko 
Published: July 2007

AbstractThis study presents data showing individual differences in aldehyde oxidase activity in human and monkey liver cytosols. When assayed with benzaldehyde as a substrate, a significant inter‐subject variation in the activity was found in the human liver preparations. When assayed with N1‐methylnicotinamide as a substrate, the inter‐subject variation of the activity was also observed, but to a lesser extent compared with that of the activity with benzaldehyde. Similarly, variations in aldehyde oxidase activity were found in the monkey liver preparations when assayed with benzaldehyde or N1‐methylnicotinamide. The present study suggested that at least two isozymes of aldehyde oxidase exist in the human liver preparations.
Denaturation of uridine phosphorylase from Escherichia coli K‐12 by guanidine hydrochloride
Authors: Kurganov B. I. , Burlakova A. A. , Chernyak V.Ya. , Debabov V. G. 
Published: July 2007

AbstractDenaturation of uridine phosphorylase from Escherichia coli K‐12 by guanidine hydrochloride results in red shift of the maximum in the protein fluorescence spectrum, dissociation of the hexameric enzyme molecule into monomers, and the loss of the enzymatic activity. The initial rate of the enzyme reactivation after the dilution of the enzyme preincubated with guanidine hydrochloride has the second order with respect to protein. It is assumed that the rate of the reactivation process is limited by the reassociation of monomers possessing low enzymatic activity to dimers followed by the rapid step of hexamer formation.
High salt and solvent induced Z‐conformation in native calf thymus DNA
Authors: Ali Naushad , Ali Rashid 
Published: July 2007

AbstractThe Z‐DNA forming potentiality of native calf thymus DNA using spectrophotometric measurements and diethyl pyrocarbonate reactivity have been investigated. The [image omitted] value was evaluated from absorbance ratio for B‐ and Z‐DNA and compared with the values obtained for native DNA. The results suggest that native DNA undergoes B‐ to Z‐/Z‐analogous transition to an extent of 20 per cent under constraint conditions. Possible Z‐DNA formation was also characterized by hyper‐reactivity of native DNA towards diethyl pyrocarbonate in aqueous solvent. The thermal melting profile of native and modified DNA and nuclease S1 digestibility data, in addition, reflects B‐ to Z‐/Z‐analogous transition in native DNA.
Nanomolar concentrations of gangliosides stimulate primary humoral response
Authors: Dozmorov I. M. , Prokhazova A. L. , Svirtshevskaya E. V. , Lutsan N. I. , Kozin I. I. , Lemenovskaya A. F. , Dyatlovitskaya E. V. , Bergelson L. D. 
Published: July 2007

AbstractExogenous gangliosides act as immunosuppressors when applied at micromolar concentrations corresponding to their average level in human plasma. Here we show that at nanomolar concentrations the gangliosides GD3, GD1a and GM1 can act as immunostimulators markedly enhancing the number of plaque‐forming cells in mouse splenocyte culture responding to sheep erythrocytes. At such low concentration these gangliosides as well as GM3 were not able to influence significantly proliferative responses of splenic B and T lymphocytes or of cytotoxic T‐cells. Neither did they change significantly the production of IL‐1 by antigen‐ representing cells, or of IL‐2 by Con A‐induced blasts in the splenocyte culture. It is suggested that the stimulatory effect of low ganglioside concentrations on humoral response is due to their influence on cooperative cell‐cell interactions required for the differentiation of B‐cells into Ig‐secreting cells.
Acetylcholinesterase activity of normal and diabetic human erythrocyte membranes: The effect of oxidative agents
Authors: Krajewska Emilia , Zavodnik Ilya , Kluska Beata , Szosland Konrad , Bryszewska Maria 
Published: July 2007

AbstractThe activity characteristics of membrane acetylcholinesterase from red blood cells of diabetic patients are very different from those of healthy donors: the limiting enzyme reaction rate is 17.2±0.8 μmol acetylthiocholine per ml packed cells per min compared with 13.1±0.8 μnol for control cells. The Michaelis constants for substrate are the same: 0.061±0.007 mM for diabetic and 0.061±0.004 mM for control cells. Cell exposure to oxidative agent (t‐butyl hydroperoxide) significantly changes the enzyme activity parameters. The limiting enzyme reaction rate increases but the affinity for the substrate decreases at lower oxidant concentrations (up to 0.1 mM for the “diabetic” erythrocytes and up to 0.4 mM for the control ones). At higher oxidant concentrations both the limiting reaction rate and the Michaelis constant decrease. The susceptibility of erythrocyte membranes of diabetic patients to oxidative stress is much higher in comparison with control erythrocyte membranes.
Effect of thiols on fructosamine assay
Authors: Liu Wei , He Rongqiao 
Published: July 2007

AbstractFresh human serum, gGAPDH and β‐mercaptoethanol were used to examine the effect of thiols on fructosamine assay. The kinetics of the reaction with both fresh human serum and gGAPDH displayed biphasic behaviour (fast and slow). When the thiols were modified with IAA, the kinetics only demonstrated the slow phase. Since the absorbance increase in the interval from 9 to 10 min was used in the fructosamine assay of glycated human serum we studied the effect of thiols on that measurement. In the case of gGAPDH, the value was approximately one‐half of the original after thiol modification, suggesting thiol interference. Nevertheless, gGAPDH may contain a fructosamine structure, β‐Mercaptoethanol itself gave a strong positive result in the fructosamine assay. Hence, thiol groups on glycated proteins should be modified before doing a fructosamine assay because of their substantial interference.
Activity and carboxylation specificity factor of mutant ribulose 1,5‐bisphosphate carboxylase/oxygenase from Anacystis Nidulans
Authors: Romanova Alla K. , Zhen‐qi‐Cheng  , McFadden Bruce A. 
Published: July 2007

AbstractThe values of molecular carboxylase activity kcat and carboxylation specificity factor τ for mutant ribulose 1,5‐bisphosphate carboxylase (rubisco) from Anacystis nidulans decreased as compared to those of the wild type recombinant rubisco. The substitution of five amino acid residues in rubisco large subunit Lys,AIa,Ser, Thr, Leu(339‐343)Phe,Leu,Met,Ile,Lys had kcat decreased by 90% and τ by 36.3%. The same parameters for mutants with the single replacements decreased: for Thr342Ile kcat by 40.5% and τ by16.7%, and for mutant Leu343Lys kcat by 48.1% and τ by 18.5%. Mutant rubisco with three amino acid resudues changed Val,Asp,Leu(346‐348)Tyr,His,Thr was inactive. The substitution Leu326Ile decreased kcat by 54.4% and τ by 34.2%; and change Ser328Ala decreased kcat only by 5.6% but τ by 41.5%. Replacement Asn123His decreased kcat by 16.5%. Significance of the non conservative amino acid residues for carboxylase activity and ribulose‐l,5‐bisphosphate partition is discussed.
Effect of 5‐fluorouracil on interleukin‐1 and interleukin‐2 receptor expression
Authors: Balaji K. N. , Nayak R. 
Published: July 2007

AbstractWe have studied the effect of anticancer drug 5‐Fluorouracil on the expression of human Interleukin‐1 and Interleukin‐2 receptor. In this report, we show that 5‐Fluorouracil increases the Interleukin‐1 expression upto 2.66 folds without significantly affecting the levels of surface expression of p55 IL‐2 receptor on human Peripheral blood mononuclear cells, CD4 and CD8 T cells. On contrary, the drug decreases the levels of Interferon‐γ secretion by upto 42%. In earlier studies we have shown that 5‐Fluorouracil increases the IL‐2 expression both at mRNA and protein levels. Taken together, 5‐Fluorouracil differentially affects the expression of Interleukin‐1, Interferon‐γ and Interleukin‐2 receptor.
Expression of the trefoil polypeptide ITF in PC12 cells
Authors: Probst Joseph Christopher , Landgraf Rainer , Behl Christian 
Published: July 2007

AbstractTrefoil polypeptides are expressed mainly in the amphibian skin and the gastrointestinal tract of mammals, usually coexpressed with mucin‐glycoproteins. Recently, the trefoil polypeptides were shown to be expressed also in different areas of the human and routine brain. To investigate the expression and possible functions of ITF in rat pheochromocytoma (PC12) ceils were employed. PC12 cells show a low basal expression of this polypeptide as determined by reverse transcriptase‐polymerase chain reaction. After treatment with the synthetic glucocorticoid dexamethasone, the second messenger cyclic adenosine monophosphate and the neurotrophic factor nerve growth factor the expression of the trefoil polypeptide ITF was increased as shown by reverse transcriptase‐polymerase chain reaction and by immunocytochemistry. Since these various stimuli can directly alter the expression level of this peptide we conclude that the presented results may form the basis for further investigations of possible functions of this novel gut‐brain polypeptide in neurons using PC12 cells.