bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid assessment of early glycation products by mass spectrometry
Authors: Prabhakaram Malladi , Smith J. B. , Ortwerth B. J. 
Published: July 2007

AbstractIn order to detect the early glycation products, we have reacted a model peptide (t‐boc‐lys‐ala‐ala) with L‐threose (a degradation product of ascorbic acid) and analyzed the reaction products by a combination of HPLC and mass spectrometry. Amino group modification, as observed by a fluorescamine assay, indicated complete modification after 3 days of incubation with a 10‐fold excess of threose. As much as 60% of the adducts were acid labile and only 4% of the adducts could be observed by amino acid analysis. However, Fast atom bombardment mass spectrometry (FABMS) of the samples incubated for 6 hr showed relative molecular masses consistent with the formation of adducts corresponding to the addition of one and two molecules of L‐threose to the peptide. Likewise, samples incubated for 12 hr showed peptide adducts with two and three L‐threoses. The number of threose molecules added to the peptide was also confirmed from the FABMS analysis by using [1‐13C]‐threose as the glycating agent.
1H‐NMR relaxometric study of pancreatic serine (pro)enzyme inhibition by a Gd(III) chelate bearing boronic functionalities
Authors: Aime Silvio , Fasano Mauro , Paoletti Silvia , Viola Franca , Tarricone Cataldo , Ascenzi Paolo 
Published: July 2007

AbstractBinding of the paramagnetic N,N″‐bis(m‐boroxyphenylcarbamoylmethyl)‐diethylenetriamine‐N,N′,N″‐triacetic acid Gd(III) complex (GdBB) to chymotrypsin, chymotrypsinogen, trypsin, trypsinogen and pancreatic elastase has been investigated by 1H‐NMR relaxometry, between pH 6.0 and 8.5, at 25.0°C. Values of Ki for the competitive inhibition of serine proteinases by GdBB are in excellent agreement with values of Kd obtained by 1H‐NMR relaxometry, suggesting that the substrate and the paramagnetic complex bind to the same region. Moreover, 1H‐NMR relaxometry allowed to determine values of Kd for GdBB binding to chymotrypsinogen and trypsinogen, both devoid of catalytic activity. The increase of the water proton relaxation rate upon GdBB binding to serine (pro)enzymes may be useful in the design of novel functional contrast agents for magnetic resonance imaging.
A novel cDNA encoding for a lim domain protein located at human chromosome 14q32 as a candidate for leukemic translocation
Authors: Tsui Stephen Kwok Wing , Chan Peggy Pik Kwan , Cheuk Chin Wah , Liew Choong Chin , Waye Mary Miu Yee , Fung Kwok Pui , Lee Cheuk Yu 
Published: July 2007

AbstractA full‐length cDNA clone encoding a zinc finger protein was isolated and sequenced. This full‐length clone consists of 728 bp and has a predicted open reading frame (ORF) encoding 208 amino acids. The ORF of this polypeptide codes for the human cysteine‐rich protein 2 (HCRP2) and has an amino acid sequence that is 92.8% identical to its rat homolog (RCRP2). HCRP2 was mapped to chromosome 14q32, which is a hot spot of translocation in tumor development, by fluorescent in situ hybridization (FISH).
3‐Hydroxybutyrate decreases noradrenaline affinity for rat erythrocyte ghost β2‐adrenergic receptors
Authors: Gómez G. , Cañas X. , Fernández‐López J. A. , Remesar X. , Alemany M. 
Published: July 2007

AbstractThe effects of physiological levels of 3‐hydroxybutyrate on noradrenaline binding to rat erythrocyte membranes were studied. The binding of noradrenaline to membranes was determined by measuring the union of 3H‐noradrenaline in the presence of varying concentrations of 3‐hydroxybutyrate. Scatchard plots of the results were used to determine that 3‐hydroxybutyrate provoked a loss of affinity of the β2‐adrenergic receptors for adrenaline. Thus high (but physiological) 3‐hydroxybutyrate levels can lower the binding of the catecholamine, thus diminishing the extent or intensity of adrenergic‐driven responses
Characterization of the purified cytosolic thymidine kinase from murine Ehrlich ascites tumor: Interconversion of two different relative molecular weight forms
Authors: Tsukifuji‐Nabeya Reiko , Yusa Toshikazu , Kuroiwa Namiko , Kumazawa Takeshi , Tamiya Norihisa , Moriyama Yoichi , Okamoto Shoji , Yamaguchi Yutaka , Fujimura Shinji 
Published: July 2007

AbstractCytosolic thymidine kinase was purified 18,000‐fold of the homogenate from murine Ehrlich ascites tumor, using the [p‐aminophenyl 3′‐dTMP]‐CH‐Sepharose affinity column. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of the purified enzyme showed a single protein band of molecular weight 26,000. Two different forms, relative molecular weight 50,000 and 70,000, were found by gel filtration, depending on the existence of dithiothreitol, ATP and other nucleotides. These agents also stabilize and stimulate the enzyme activity. The existence of two forms was also manifested by DEAE‐Sephacel column chromatography, where the 50,000 form was eluted by 50 mM NaCl and the 70,000 form by 400 mM NaCl.
Effect of a cholesterol‐rich diet on the excitability of rabbit aorta
Authors: Wong Kai K. 
Published: July 2007

AbstractThe level of plasma total cholesterol in rabbits after 8‐week feeding on a cholesterol‐rich diet was raised significantly. The excitability of the rabbit aorta in response to the depolarizing agent KC1 was enhanced, demonstrating an increased sensitivity to KC1 stimulation as well as an increase of the KC1‐induced maximum tension. It is speculated that 7 weeks of hypercholesterol state may vary the membrane lipid composition, enhancing the aortic excitability in response to depolarizing agent.
A low molecular weight urokinase derivative with enhanced fibrin affinity
Authors: Chen Xiao‐Chun , Hua Zi‐Chun , Zhu De‐Xu 
Published: July 2007

AbstractA Gly‐Pro‐Arg‐Pro tetrapeptide, homologous to amino‐terminal segment of the human fibrin α chain after the release of the fibrinopeptide A, was covalently coupled to peptide A of low molecular weight urokinase. The resulting derivative gained increased affinity for fibrin. In caseinolytic assay, fibrin can stimulate the derivative to activate plasminogen. The derivative had two‐fold greater fibrinolytic potency than native low molecular weight urokinase and its affinity for fibrin clot was 3.9‐fold higher than that of low molecular weight urokinase.
Binding of non‐homologous series of anticancer drugs to cytosine
Authors: Cserháti Tibor , Forgács Esther 
Published: July 2007

AbstractThe interaction of 20 anticancer drugs with cytosine was studied by charge‐transfer reversed‐phase thin‐layer chromatography. The hydrophobicity, the specific hydrophobic surface area and the relative strength of interaction was calculated. Significant linear correlation was found between the hydrophobicity and specific hydrophobic surface area of drugs; this means that, from the chromatographic point of view, they form a homologous series of solutes. Only eight anticancer drugs showed significant interaction with cytosine. The binding of these drugs to cytosine (and possibly to other nucleotides) might be an important interaction which plays a role in the biological activity of drugs.
Hysteretic properties of rabbit skeletal muscle phosphorylase kinase: Synergistic activation by phosphorylase b, Ca2, and Mg2
Authors: Kurganov B. I. , Andreeva I. E. , Makeeva V. F. , Livanova N. B. 
Published: July 2007

AbstractTo study the hysteretic properties of rabbit skeletal muscle phosphorylase kinase the method of continuous registration of the kinetics of the kinase reaction developed by us earlier has been used. It was shown that duration of the lag period on the kinetic curves is independent of the phosphorylase kinase concentration and the simultaneous presence of phosphorylase b, Ca2+, and Mg2+ is required for the complete transition of the enzyme into the activated state.
cDNA sequence analysis of a novel cardiotoxin‐like protein from Taiwan banded krait
Authors: Chang Long‐Sen , Lin Jordge 
Published: July 2007

AbstractThe cDNAs encoding a novel protein was constructed from the cellular RNA isolated from the venom glands of Bungarus multicinctus by reverse transcription‐polymerase chain reaction. The deduced amino acid sequence of this novel protein contained 65 amino acid residues with 8 cysteine residues. Comparative sequence analysis showed that it was structurally related to cardiotoxin rather than neurotoxins. These results suggest that the venom of Bungarus multicinctus may contain cardiotoxin(s) which was not noticed before.
Intracellular distribution of polyamines in human lymphoblastoid cell line during phorbol ester‐induced differentiation
Authors: Stabellini Giordano , Creati Beatrice , Primio Roberto Di , Trubiani Oriana 
Published: July 2007

AbstractPolyamines such as putrescine, spermidine and spermine play an important role in nucleic acid metabolism. These aliphatic amines display a key role in cell‐induced transformation by carcinogenic substances. In particular, one of these, the phorbol myristate acetate, provokes cell differentiation and gives an increase of ornithindecarboxylase activity; enzyme regulating the pathways of polyamines. In this study we analyse the trend of the polyamines at cytoplasmic and nuclear level during phorbol treatment. Our results show a correlation between nuclear and cytoplasmic spermine, 3H‐Thymidine, 3H‐Leucine incorporation and cell cycle phases. These data remark that the polyamines are differently distributed into the cell during the phorbol myristate acetate‐mediated differentiation process and that the spermine is down‐regulated for to supply the increased protein biosynthesis.
Sequence‐specific interactions of minor groove binders with the 154 base pair hindlll‐rsal restriction fragment of cDNA of the human tau 40 protein involved in pathology of alzheimer's disease
Authors: Kittler Leonhard , Matesoi Diana , Bell Achim , Baguley Bruce C. , Unger Eberhard , Löber Günter 
Published: July 2007

AbstractThe DNA minor groove binders netropsin, distamycin and four structurally related bisquaternary ammonium heterocycles (BQA), SN 6999, SN 6570, SN 6132 and SN 6131, were investigated for sequence‐specific interactions with the 154 base pair fragment of cDNA of the human Tau 40 protein (h Tau 40 protein), involved in pathology of Alzheimer's disease. The base sequences 5′ AATCTT 3′, 5′ AATATT 3′ and 5′ TTTCAATCTTTTTATTT 3′ were identified as ligand specific binding sites and demonstrate the obvious dA·dT binding preference. Footprinting titration experiments were performed to estimate sequence‐specific binding constants (KA). The KA‐Values were in the order of 106M‐1 and dependent on DNA base sequence as well as ligands used. The highest values estimated were for netropsin (KA=5.0×106M‐1) and the quinoline derivative SN 6999 (KA=6.2×106M‐1) binding to the sequence 5′ ATAAT 3′. Microscopic binding constants are determined by the base sequence rather than by the length of dA·dT stretches. In the extended dA·dT run, 5′ TTTCAATCTTTTTATTT 3′, netropsin and distamycin binding tolerates the presence of two dG·dC base pairs, as indicated by nearly unaffected footprints. In contrast, the failure of BQAs to form footprints demonstrates their significantly decreased binding selectivity.
Cell volume regulation in Claviceps fusiformis. An animal‐type Na,K‐ATPase operating in a fungus?
Authors: Rauferová Ludmila , Metlička Rudolf , Beneš Ivan , Kotyk Arnošt , Janáček Karel 
Published: July 2007

AbstractClaviceps fusiformis, an ergot pathogen of pearl millet, was equilibrated in media without and with 0.1 mM ouabain (g‐strophantin). Highly significant effects of ouabain on the contents of sodium ions and water were found, suggesting that an active transport of sodium ions, similar to that in animal cells, regulates the cell volume of the fungus. The basic role of the sodium pump appears to be to decrease larger cell volumes and to increase the small ones; for this purpose it can even reverse its direction.
Effect of intramitochondrial Mg2 on citrulline synthesis in rat liver mitochondria
Authors: Rodríguez‐Zavala José S. , Saavedra‐Molina Alfredo , Moreno‐Sánchez Rafael 
Published: July 2007

AbstractA correlation was found between mitochondrial matrix free magnesium ([Mg2+]m), measured by means of the fluorescent indicator Mag‐Fura‐2, and citrulline synthesis in rat liver mitochondria. The variation of [Mg2+]m from 0.05 to 1.7 mM by changes in external Mg2+, induced a 20 + 8.5% increase in the rate of citrulline synthesis, whereas a further increase of [Mg2+]m to 3.3 mM induced a return to basal values. The increase in [Mg2+]m, as well as the diminution of external pH, also promoted an elevation of matrix free Ca2+ ([Ca2+]m). An increase in [Ca2+]m, at constant [Mg2+]m and pH, resulted in a 3‐fold stimulation of citrulline synthesis. The data suggest that [Mg2+]m may modulate the rate of citrulline synthesis through a direct interaction with carbamoyl‐phosphate synthase I (ammonia) and, indirectly. by changing the levels of matrix Ca2+.
Interaction of recombinant rat nucleoside diphosphate kinase α with bleached bovine retinal rod outer segment membranes: A possible mode of pH and salt effects
Authors: Orlov Nicolay Ya. , Orlova Tatiana G. , Reshetnyak Yana K. , Burstein Edward A. , Kimura Narimichi 
Published: July 2007

AbstractAn attempt was made to reveal the mode of action of protons and salts on the recently discovered GTPγS‐dependent interaction of bovine retinal rod outer segments (ROS)1 nucleoside diphosphate kinase (NDP kinase) with the complex between bleached visual receptor rhodopsin and retinal G‐protein transducin in bovine ROS membranes. The properties of recombinant rat NDP kinase α, that is immunologically similar to the soluble NDP kinase from bovine ROS preparation, have been studied in solution by means of protein fluorescence at different pH and salt concentrations and results were compared with pH and salt effects on the binding of NDP kinase α to bleached bovine ROS membranes. The results suggest that NDP kinase α itself may serve as a target for protons and salts and mediates their effects on the interaction between the enzyme and ROS membranes.
Identification of the functional improtance of valine‐19 residue in streptokinase by N‐terminal deletion and site‐directed mutagenesis
Authors: Lee Si Hyoung , Jeong Seong Tae , Kim Il Chul , Byun Si Myung 
Published: July 2007

AbstractStreptokinase (SK) is a bacterial plasminogen activator of multi‐domain structure. In deletion analysis of the N‐terminal region of SK, the deletion of 20 amino acids (SKΔN20) resulted in the dramatic reduction of plasminogen activator activity compared to deletion of 7 (SK ΔN7) and 13 amino acids (SKΔN13). The incubation time to reach maximal active site generation in an equimolar mixture of SKΔN20 and plasminogen was the same as that for wild‐type SK. To identify the functional residues important in plasminogen activation, several site‐directed mutations were introduced at the region spanning Serl6‐Val20 of SK. The results showed that Vall9 residue is important for the activity of the SK‐plasminogen complex.
Immunoreactivities of p11 and calcyclin in baker's yeast, wheat germ and lobster
Authors: Kuo W. N. , Jn‐Baptiste J. B. , Zhai L. , Chambers M. C. , Kanadia R. 
Published: July 2007

AbstractAfter effectively eliminating the nonspecific cross‐immunoreactivity with the affinity columns of anti‐IgG agarose and IgG agarose, the potent immunoreactivities of p11 and calcyclin in wheat germ, lobster tail muscle, and three strains of baker's yeast were analyzed by Western blotting using mouse anti‐p11 and rabbit anti‐calcyclin. The occurrence of multiple bands may be due to either autolyses and/or the interactions between the p11 (or calcyclin) and other endogenous biological molecules. The results suggest not only a ubiquitous distribution and a universal Ca2+‐mediating regulatory role of p11 and calcyclin in eukaryotes, but also an evolutionary conservation of these (S‐100)‐related proteins.
Opposite effects of isoniazid and fasting on the expression of CYP2E1 protein and mRNA in house musk shrew (Suncus murinus)
Authors: Nakura Hironori , Itoh Susumu , Kusano Hisashi , Ishizone Hiroyuki , Kamataki Tetsuya 
Published: July 2007

AbstractThe effects of isoniazid and fasting on hepatic CYP2E1 in the suncus were investigated. Aniline hydroxylation and N‐nitrosodimethylamine demethylation, which are known to be catalyzed by CYP2E1, in liver microsomes were induced and suppressed by the treatment with isoniazid and the fasting, respectively. Immunoblot analysis indicated that CYP2E1 protein in liver microsomes from isoniazid‐treated suncus was increased in contrast to the result with the fasting of the suncus. Northern blot analysis showed that the treatment of suncus with isoniazid increased the expression of CYP2E1 mRNA in livers although the fasting of the suncus significantly decreased CYP2E1 mRNA. These results suggest that the regulation of hepatic CYP2E1 in the suncus by treatment with isoniazid and fasting was different from that in rats.
Inhibition of DNA synthesis in CCL 39 cells by impermeable iron chelators
Authors: Alcaín Francisco J. , Löw Hans , Crane Frederick L. 
Published: July 2007

AbstractThe synthesis of DNA in CC1 39 cells is inhibited by the presence of the Fe2+ chelator bathophenanthroline disulfonate (BPS) when growth is stimulated by thrombin EGF plus insulin, but not by fetal calf serum. The presence of transferrin and Fe3+ in fetal calf serum can be the basis for lack of BPS effect with serum. The impermeable Fe3+ chelator Tiron does not, by itself inhibit growth factor induced DNA synthesis, but it induces together with BPS inhibition on fetal calf serum induced DNA synthesis. The combined effect of BPS and Tiron is similar to inhibition of DNA synthesis by impermeable polyvalent DTPA which can chelate both Fe2+ and Fe3+ but does not inhibit ribonucleotide reductase in intact cells. Ferrous iron that bind BPS can relieve the inhibition at stoichiometric concentration. Ferric iron also prevents the inhibition even though it does not bind BPS. BPS does not inhibit DNA synthesis in HeLa cells. BPS reacts with iron from CC1 39 cells but not from HeLa cells. Data show that iron available for impermeable external chelators is in the ferrous state, and that exogenous iron should be reduced before it reverses the inhibition.
Changes in protein composition during chick embryo retina development
Authors: Carabillò M. , Gerbino E. , Main H. , Calvaruso G. , Tesoriere G. 
Published: July 2007

AbstractTwo dimensional gel electrophoresis was employed to analyse the protein composition of chick embryo retina during “in ovo” development in order to individuate some components which are typical of different stages of growth. The study of protein composition of 7‐day‐old chick embryo retinas revealed the presence of about eighty different soluble components. In four of these proteins the staining intensity decreased during retina development. One of these components, of 35 KD with an isoelectric point of about 5.15, was partially purified by means of preparative isoelectric focusing. Other components, which were absent at day 7 appeared during the second week of development and were clearly visualised at day 16. These results were also compared with those obtained by means of 2DGE performed on liver and brain of chick embryo at day 7 and 16 of development.
Purification and partial characterization of chromogranin‐A from human brain
Authors: Kumar Ujendra 
Published: July 2007

AbstractChromogranin A was purified from post‐mortem human brain tissue, obtained at autopsy by a three step chromatography procedure to a single band purity on SDS gel electrophoresis at 68 kDa. Purified protein was further characterized by immunoblotting using a mouse anti‐chromogranin A monoclonal antibody LK2H10, which recognizes the 68 kDa chromogranin A in human brain. The results demonstrate a simple protocol of preparing CgA from the human brain. Chromogranin plays a very important role in various neurological disorder and has been examined immunohistochemically in Alzheimer's disease, Parkinson's disease, Pick's disease. The procedure of purification may be useful in further defining its biological function, biochemistry and physiological significance in the central nervous system and may be useful in delineating the molecular pathology of certain neurological disorders.
The effects of chronic administration of nimodipine on age‐related changes in nitric changes in nitric oxide and its synthase in senescence‐accelerated mouse brain
Authors: Inada Kazunori , Yokoi Isao , Kabuto Hideaki , Namba Yukiko , Ogawa Norio 
Published: July 2007

AbstractThe levels of nitric oxide (NO) and NO synthase (NOS) activities in the brain of young‐adult (3 months old), aged (11 moths old) and nimodipine‐administered (11 months old) senescence‐accelerated mouse (SAM), of which SAMP8 sub‐strain is inferior in acquisition of learning and has a lower content in testosterone, were compared. Nimodipine, which is L‐type calcium ion channel blocker and has memory‐enhancing effects, was administered orally for 5 months. In the cerebral cortex of aged SAMP8, NOS activity was increased compared with that of young‐adult SAMP8. Though nimodipine did not alter the contents of NO in any brain regions compared with those in aged SAMP8, nimodipine increased NOS activity in the aged cerebellum. Our data suggest that nimodipine may increase NOS activity through elevation of testosterone level, as testosterone increases NOS only in the cerebellum, although further work is clearly needed to ascertain effects of nimodipine on testosterone metabolism and maintenance in the acquisition of learning.
Protective effect of vitamin E against ethionine toxicity
Authors: Padma P. , Setty O. H. 
Published: July 2007

AbstractThe effect of administration of ethionine on rat liver mitochondrial functions and the protective effect of vitamin E on ethionine induced damage was studied. Ethionine treatment decreased the rate of respiration, respiratory control ratio and P/O ratio. There was a significant decrease in the activities of NADH dehydrogenase, succinate cytochrome C reductase and cytochrome oxidase. A significant decrease was seen on membrane potential and on the levels of ATP. Among the mitochondrial phospholipids only cardiolipin decreased significantly. The lipid peroxide level increased significantly in ethionine treated rats. Administration of vitamin E prior to ethionine treatment relieved the effects (induced by ethionine) on all the parameters studied. This study shows that vitamin E protects against ethionine toxicity.
Altruistic DNA
Authors: Patrushev L. I. 
Published: July 2007

AbstractThere has been designed a model to explain the main function of abundant DNA sequences in the eukaryotic genome. The non‐coding abundant sequences are supposed to provide two levels of protection of functionally important genome regions against mutations: global and differential. At the first level rather high excess of the nucleotide sequences over the coding ones decreases probability of mutations in coding and other functionally important parts caused by intranuclear mutagens. The second level is achieved by specific chromatin condensation in individual microcompartments of the interphase nucleus and physical accessibility of functionally important sequences to mutagens. These mechanisms might control the optimum mutation rates in some functionally important loci in ontogenesis and might be of help to establish a preferable trend of evolutionary transformations of biological species in phylogenesis.