bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cystatin‐like domain of mouse countertrypin, a member of mammalian fetuin family, is responsible for the inhibition of trypsin. Evidence from site‐directed mutagenesis
Authors: Yoshida Koji , Suzuki Yasuyuki , Yamamoto Kazuhiko , Sinohara Hyogo 
Published: July 2007

AbstractMembers of mammalian fetuin family, such as human α2HS glycoprotein and bovine fetuin, consist of three domains, two tandemly arranged cystatin‐like domains and an unrelated domain, but they have no inhibitory activity against cysteine proteinases. We found that countertrypin, a novel trypsin inhibitor, is mouse counterpart of human α2HS glycoprotein, and that human α2HS glycoprotein and bovine fetuin which were prepared without use of ethanol are capable of inhibiting trypsin (Yamamoto, K. and Sinohara, H. (1993) J. Biol. Chem, 268, 17750‐17753). In the present study, cDNA encoding countertrypin was isolated and sequenced, and evidence is presented, based on the site‐directed mutagenesis, that lysine‐231 in the second cystatin domain is the P1 site for trypsin inhibition.
Cytochrome P450scc spin state transitions in the thin solid films
Authors: Guryev O. , Erokhin V. , Usanov S. , Nicolini C. 
Published: July 2007

AbstractLangmuir‐Blodgett films of cytochrome P450scc were prepared on the solid supports and their spectral properties were investigated. Being immobilized, hemoprotein changes its spin state from initially high to low spin. This transition is reversible since after the solubilization of hemoprotein, the spin state equilibrium is shifted towards high‐spin state. Anaerobic reduction of film incorporated cytochrome P450scc by electron transfer chain (NADPH→adrenodoxin reductase→adrenodoxin) revealed the low rate of the reaction that coincides well with the content of the hemoprotein low‐spin form. We suggest that particularly regular orientation of solid cytochrome P450scc are of crucial importance for this phenomenon.
Stem cell factor protects bone marrow‐derived cultured mast cells (BMCMC) from cytocidal effect of nitric oxide secrected by fibroblasts in murine BMCMC‐fibroblasts coculture
Authors: Park Sung‐Joo , Jun Chang‐Duk , Choi Byung‐Min , Lee Eun‐Jung , Kim Hyung‐Ryong , Cho Hae‐Won , Chung Hun‐Taeg 
Published: July 2007

AbstractThe survival of mast cells are dependent on two kinds of growth factors, one derived from T cells (IL‐3) and another derived from fibroblasts (stem cell factor [SCF]). The 3T3 fibroblast cell line derived from WCB6Fl‐+/+ mouse embryos (+/+ 3T3 fibroblasts) supported the proliferation of bone marrow‐derived cultured mast cells (BMCMC) in the PWM‐stimulated spleen cell conditioned medium (PWM‐SCM), whereas the 3T3 fibroblast cell line from WCB6Fl‐Sl/Sld mouse embryos (Sl/Sld 3T3 fibroblasts) did not. To study the role of nitric oxide (NO) on the growth of mast cells in BMCMC‐fibroblasts coculture, we used a NO synthase inhibitor, NG‐monomethyl‐L‐arginine (NGMMA). NGMMA recovered survival and maintained proliferation of mast cells in BMCMC‐Sl/Sld 3T3 fibroblasts coculture. Sl/Sld 3T3 fibroblasts as well as 3T3 fibroblasts from NIH‐+/+, BALB‐+/+ or Swiss‐+/+ mouse embryos secreted NO in PWM‐SCM, but not in α‐MEM. SCF protected BMCMC from cytotoxicity of exogenous NO in IL‐3‐supplemented α‐MEM. We concluded that SCF might protect BMCMC from cytocidal effect of NO in BMCMC‐fibroblasts coculture.
Erythrocyte membrane Na,K ATP ase activity can be a marker of liver histopathology
Authors: Kuralay Filiz , Tanyalçin Tijen , Kutay Fatma , Yuce Gül , Ersoz Galip , Batur Yücel 
Published: July 2007

AbstractErythrocyte membrane Na+,K+; Ca2+ ATP ase activities, cholesterol (CH) phospholipid (PL) composition and erythrocyte glutathione (GSH) contents were determined in controls, in patients with chronic active hepatitis and liver cirrhosis. Na+,K+ ATP ase activities were significantly (P<0.0001) less in patients with chronic active hepatitis and liver cirrhosis (n=8, 0.102 ± 0.02 µmol P/mg protein/hour; n=8, 0.081 ± 0.02 µmol P/mg protein/hour) than in controls (n=10, 0.219 ± 0.05). Histopathological analysis of liver sections obtained from patients with chronic active hepatitis (n=3) and liver cirrhosis (n=2) correlated well with erlthrocyte biochemical findings. There was a significant negative correlation between Na+,K+ ATP ase activity and portal fibrosis (P<0.05, r=‐8680). However, further experiments performed on larger study populations are needed to better elucidate this correlation. Therefore, Na+,K+ ATP ase activity measurement can be reliable assessment of liver fibrosis.
Purification and enzymatic peptide mapping of protein synthesis elongation factor‐2 from mink and chicken livers
Authors: Riis Bent 
Published: July 2007

AbstractThis investigation has shown it is possible to purify elongation factor‐2 from livers of two rather distinct animal species, minks and chicken, to high homogeneity by employing the same purification procedure. It is also shown that making peptide maps of the factor by the use of Staphylococcus aureus Endoprotease Glu‐C gives the same pattern. Combined, these two experimental approaches show that the evolution has conserved this elongation factor in two species with a rather different physiology and choice of feeding substances. It is also shown that using mink or chicken livers as staring material for purification of eEF‐2 is both technically and economically sound when obtaining large amounts of highly purified eEF‐2 is the ultimate goal.
The amino acid sequence of the spinach basic cupredoxin plantacyanin
Authors: Mann Karlheinz , Eckerskorn Christoph , Mehrabian Zara , Nalbandyan Robert M. 
Published: July 2007

AbstractWe describe the amino acid sequence of plantacyanin isolated from spinach leaves. This small basic copper‐binding plant cupredoxin contains 91 amino acids (accession no.S70746) and its theoretical average mass of 9788.2 Da was confirmed by electrospray ionization mass spectrometry. When compared to the sequences of other plant cupredoxins, the most similar homologs were cucumber basic blue protein and stellacyanin from Laquer tree with 44‐58% identical residues. Other known plant cupredoxins were significantly less similar which may allow to divide the plant cupredoxins into two subgroups, the single‐domain cupredoxins (plantacyanin, cucumber basic blue protein and stellacyanin) and the two‐domain, hydroxyproline‐containing cupredoxins (cucumber peeling cupredoxin, basic blue protein from Arabidopsis thaliana and horseradish umecyanin).
Effect of cycloheximide on the expression of LPS‐inducible iNOS, IFN‐β, and IRF‐1 genes in J774 macrophages
Authors: Hattori Yoshiyuki , Akimoto Kazumi , Matsumura Michiko , Tseng Chen‐Chiang , Kasai Kikuo , Shimoda Shin‐Ichi 
Published: July 2007

AbstractThe effect of cycloheximide (CHX) on the gene expression for inducible NO synthase (iNOS), interferon (IFN)‐β, and IFN regulatory factor (IRF)‐1 was examined in LPS‐stimulated J774 macrophages. LPS caused increased expression of mRNAs specific for iNOS, IFN‐β, and IRF‐1 with different kinetics. Addition of CHX resulted in inhibition of the LPS‐induced iNOS gene expression and parallel decrease in NO production. In contrast, expression of IFN‐β and IRF‐1 genes in response to LPS was potentiated in the presence of CHX. These results indicate that de novo protein synthesis is not required for IFN‐β and IRF‐1 gene expression and that ongoing protein synthesis including IFN‐β and IRF‐1 may be involved in the induction process of iNOS in mouse macrophages.
Transblot identification of avidin‐interacting proteins in rat salivary glands
Authors: Shirakawa Satoko , Murata Takatoshi , Mochizuki Hajime , Takehara Tadamichi , Kobayashi Shigeru , Haneji Tatsuji 
Published: July 2007

AbstractBlotting of rat parotid gland proteins separated by SDS‐PAGE and transferred to Immobilon transfer membranes revealed that avidin‐peroxidase conjugate interacted with bands having estimated molecular weights of 72, 74, and 120 kDa. Even at the lowest concentration of avidin‐peroxidase used in the general ABC method (1:2000 dilution), three bands were clearly discernible. The staining reaction of parotid gland proteins was eliminated on preincubating the proteins with native avidin. The staining reaction was markedly reduced with the proteins obtained from submandibular/sublingual glands.
The role of multivalent cations in oligonucleotide cellular uptake
Authors: Wu‐Pong Susanna 
Published: July 2007

AbstractOligodeoxynucleotides (ONs) are a powerful new class of drugs whose transport to the cytoplasm or nucleus inefficient and incompletely defined. Thus, to further extend our understanding of the mechanism of ON cellular uptake, the role of multivalent cations in ON cellular uptake was examined. All the multivalent cations tested, except magnesium, significantly increase ON uptake and was predictably related to the cation's electronegativity but only partially due to an increase in surface‐binding. In addition, the primary mechanism of uptake is largely independent of trypsin‐sensitive surface components, cellular energy, and several specific, calcium‐dependent cellular processes. Therefore, On cellular uptake may involve an interaction between multivalent cations and either the ON, the cell membrane, or both.
Mitochondrial NADH dehydrogenase activity and ability to tolerate acetaldehyde determine faster ethanol production in Saccharomyces cerevisiae
Authors: Shankar C. S. , Ahamad P.Y. Aneez , Ramakrishnan M. S. , Umesh‐Kumar S. 
Published: July 2007

AbstractIn rapidly fermenting yeast, the rotenone insensitive mitochondrial NADH dehydrogenase was not completely repressed by high glucose. This activity appeared to enhance the glycolytic rate due to which acetaldehyde accumulated intracellularly. To overcome the toxicity of acetaldehyde, the strain produced stress proteins. During late stationary phase of growth, the accumulated acetaldehyde was converted to ethanol resulting in faster ethanol production.
Cellular and subcellular localization of glycogenin in chicken retina
Authors: Miozzo Maria C. , Maldonado Cristina , Curtino Juan A. 
Published: July 2007

AbstractWe investigated the cellular and subcellular localization of glycogenin in chicken retina using a polyclonal antibody raised against chicken muscle glycogenin. The antiserum recognized both free and glycogen‐bound glycogenin on dot blots. Immunocytochemistry revealed an uniform staining of all the retina layers except for the outer segments and ganglion cells layers that were very weakly stained and for the inner segments layer and a zone between the inner nuclear and inner plexiform layers that were heavily stained. Electron microscopy of neuronal cells showed immunoreactivity localized in the cytoplasm and nucleus. This is the first description of the cellular and subcellular localization of glycogenin. Our results suggest that the biosynthesis of glycogen could begin in both, the cytoplasm and nucleus of the neurone.
Characterization of the C‐terminal domain of ras‐GTPase‐activating protein (ras‐GAP) as substrate for epidermal growth factor receptor and p60c‐src kinase
Authors: Borowski Peter , Kornetzky Lutz , Heiland Max , Roloff Sandra , Weber Wolfgang , Laufs Rainer 
Published: July 2007

AbstractWe describe in vitro tyrosine phosphorylation of the C‐terminal 334 amino acids of ras‐GTPase‐activating protein (ras‐GAP)1 that contains the activity domain for ras interaction. To date, there have been no other phosphorylation sites determined than the reported in N‐terminal domain of ras‐GAP Tyr‐460, which is considered to be the major phosphorylation site of ras‐GAP. In our assays some differences of the kinetic parameters were observed when the reaction was catalyzed by EGF‐R compared to p60c‐src. Enzyme specific regulation of activity is associated with autophosphorylation which leads to reduced (in case of EGF‐R) or increased (in case of p60c‐src) phosphorylation of the C‐terminal 334 amino acids of ras‐GAP (GAP334). Because of the characteristics of these investigated reactions the phosphorylation of GAP334 seems to be ‐ independent from the presence of SH2 or SH3 domains ‐ triggered off by complex mechanisms different from those regulating the phosphorylation at Tyr‐460.
Effects of 2‐deoxy‐D‐glucose on the functional state of the rat myoblast GLUT 1 transporter
Authors: Mesmer Ogubay T. , Lu Zhuomei , Xia Ling , Lo Theodore C. Y. 
Published: July 2007

AbstractBased on the rationale that internalized 2‐deoxy‐D‐glucose (dGlc) is toxic to cells, glucose transport (GLUT) defective myoblast mutants have been isolated by their ability to grow in glucose‐free medium containing dGlc. Recent studies revealed that the GLUT 1 transport process was activated when GLUT 3‐ GLUT 4‐ mutants were grown in glucose‐free medium [1]. It was therefore puzzling why these GLUT3‐ GLUT4‐ myoblasts could survive in the presence of dGlc during the mutant selection process. The present study revealed that GLUT 1 transport affinity in dGlc‐grown cells was at least four folds lower than that in control cells. This loss of GLUT 1 transport activity was apparent only after exposure to the toxic sugar analogues for more than 10 hrs. This dGlc‐mediated effect was not due to competitive inhibition by the residual dGlc carried over from growth medium, changes in glycolytic enzymes, nor accumulation of the negatively charged dGlc‐6‐PO4. In fact, GLUT 1 transcript level was elevated in dGlc‐treated cells. Both immunoprecipitation and immunoblotting studies indicated that the size of the GLUT 1 transporter in dGlc‐grown myoblasts was reduced from 52 kDa to that of the unglycosylated form (38 kDa). These findings suggest that growth in the presence of dGlc inhibits glycosylation of the GLUT 1 transporter, thus reducing its transport affinity. This inability of the GLUT 1 transporter to take up dGlc may therefore explain why GLUT 3‐ GLUT 4‐ mutants are able to grow in the presence of the toxic dGlc during the mutant selection procedure.
Structure of the N‐terminus of the Escherichia coli ribosomal protein L7/L12
Authors: Todorova Roumiana T. 
Published: July 2007

AbstractThree mutant forms of the ribosomal protein L7/ L12 (S1Y, M14Y and M26Y) were constructed in order to use the Tyr residues as internal labels at the N‐terminal region. The proteins were studied by the methods of 1H‐NMR, Fluorescence, Circular dichroism spectroscopy and Differencial scanning calorimetry. The secondary structure of N‐terminus (residues 1‐36) was predicted by the programme “Globule” [1, 2]. Y1 is located in a structurally disordered region at the free end of the molecule. M14 and M26 are located in structurally ordered regions. The replacement M14 does not change the structure of the protein. The replacement M26 disturbs the helicity in the region of the mutation. The first 1‐5 positions from the N‐terminus of L7/ L12 are disordered, the positions 7‐14 participate in an α‐helical/ β‐structural region and positions 19‐30 in a strongly α‐helical region.
Dominant negative effect of the truncated p110 subunit of phosphatidylinositol‐3 kinase
Authors: Takayanagi Junji , Kimura Koutarou , Nishioka Naoya , Akimoto Kazunori , Moriya Shigeharu , Ohno Shigeo , Fukui Yasuhisa 
Published: July 2007

AbstractEffects of p110, the catalytic subunit of PI‐3 kinase, on induction of TPA response element‐driven promoter by EGF was examined. The induction was enhanced by co‐expression of the wild type p110. The truncated p110 mutants containing the binding site for p85 but missing the catalytic activity repressed the induction. A mutant with no binding activity to p85 did not show this effect. These results suggest that PI‐3 kinase is involved in signal transduction of EGF and that the truncated p110s capable of binding to p85 serves as a dominant negative reagent for PI‐3 kinase.
The methylation pattern of a cytosine DNA‐methyltransferase gene in Arabidopsis thaliana plants
Authors: Kutueva Lyudmila I. , Ashapkin Vasili V. , Vanyushin Boris F. 
Published: July 2007

AbstractUsing a PCR‐amplified 5′‐end proximal 600‐bp fragment and two cDNA clones of cytosine DNA‐methyltransferase gene of Arabidopsis thaliana as specific probes in hybridization with plant DNA samples, hydrolyzed by methylation‐sensitive restriction endonucleases HpaII and MspI, it has been established that CCGG sites located in the 5′‐end proximal part of cytosine DNA‐methyltransferase gene are highly methylated at internal C and less but detectably methylated at external C residues. On the contrary, all CCGG sites in 3′‐terminal half of the coding region were found to be unmethylated at both external and internal C residues. No significant differences between methylation patterns of cytosine DNA‐methyltransferase gene in various organs (leaf, stem, flower) of the Arabidopsis thaliana plant were detected.
Effect of thiol reagents on functional properties and heme oxidation in the hemoglobin of Geochelone carbonaria
Authors: Torsoni M. A. , Viana R. I. , Barros B. F. , Stoppa G. , Cesquini M. , Ogo S. H. 
Published: July 2007

AbstractThe reaction of thiol reagents with G. carbonaria hemoglobin was studied, and the oxygen equilibrium and kinetic of oxidation of derivatives determined. The oxygen affinity and kinetic of oxidation of hemoglobin derivatives were modified to various extents depending on the nature of thiol reagents used. Diamide yielded approximately 80% polymeric hemoglobin, although the oxidation kinetic, and the functional properties, were practically invariant (T1/2=10.0 min.; P50 = 5.0 mm Hg at pH 7.4; alkaline Bohr effect = ‐0.64). Iodoacetamide did not modify the electrophoretic pattern significantly, although all the free SH groups of hemoglobin were alkylated. A P50 of 2.5 mmHg at pH 7.4 and the Bohr effect of ‐0.15 were obtained; the T1/2 of about 6.4 min. was shorter than that for un‐modified Hb. Similar T1/2 were obtained for Hb treated with oxidized glutathione, which produced polymeric Hb and glutathionyl‐Hb. The oxygen binding characteristics showed that both of Hb derivatives, glutathionyl‐Hb and polymeric Hb, maintain the capacity to transport the gas.
Description of a one step staggered reannealing method for directional cloning of PCR‐generated dna using sticky‐end ligation without employing restriction enzymes
Authors: Ailenberg Menachem , Silverman Mel 
Published: July 2007

AbstractA novel method is described for ligation of PCR products into vectors. It utilizes formation of sticky end sequences compatible with those generated on the plasmid. Four primers are used: two primers are designed to contain the desired sequence of the sticky end plus the sequence of the gene and the other two primers contain the same sequence as the first two primers without the additional bases. The primers are paired to create two PCR products containing the additional bases in a staggered 5′ position. Following melting and reannealing, the newly formed products contain the additional sequences as sticky overhangs compatible with the sticky ends of the plasmid.
Disulfide bond formation between the N‐terminal region of p56lck and the cytoplasmic domain of CD8 studied by Electrospray Ionization and Matrix‐Assisted Desorption/Ionization time‐of‐flight mass spectrometry
Authors: Yi Gwan‐Su , Cheong Chaejoon 
Published: July 2007

AbstractMasses of the complexes formed between the C‐terminal region of CD8α (CD8αC) and the N‐terminal region of p56lck (p56lckN) were measured by using Electrospray Ionization (ESI) and Matrix‐Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry (MS). The two peptides were incubated with various metal ions, Zn++, Cd++, Co++, Fe++ and Ca++. The complex formed from the incubation did not contain any metal ions. Instead, its mass suggested that the complex was formed by two disulfide bonds. The fact that the incubation of the complex with Dithiothreitol broke the complex confirmed into monomers that the complex was formed through disulfide bonds. The only disulfide‐mediated complex formed was hetero‐dimer (CD8αC‐p56lckN) and none of homo‐dimers (CD8αC‐CD8αC or p56lckN‐p56lckN) were observed from ESI and MALDI‐TOF mass spectrometry.
Opposite effects of basic fibroblast growth factor and heparin on heparin/heparan sulfate degrading enzymes from Flavobacterium heparinum
Authors: Cavari Simone , Vannucchi Simonetta 
Published: July 2007

AbstractHeparinase I is normally inhibited by an excess or substrate; in this paper we describe that bFGF counteracts the inhibiting effect of the substrate and that heparinase I activity is increased in the presence of bFGF. This effect was observed using heparin concentrations ranging from 10‐9 to 10‐7 M with either a ten fold molar excess or an equimolar concentration of bFGF. In addition, the degree of depolymerization of heparan sulfate produced by heparitinase from Flavobacterium heparinum was increased in the presence of bFGF.
Elastin‐derived peptide induces monocyte chemotaxis by increasing intracellular cyclic GMP level and activating cyclic GMP dependent protein kinase
Authors: Uemura Yuko , Okamoto Kouji 
Published: July 2007

AbstractAn elastin‐derived peptide with an average molecular mass of 25 kDa was shown to induce monocyte chemotaxis at the optimal concentration of 10‐1 μg/ml. Homologous deactivation test showed that monocytes exposed to the elastin‐derived peptide at 10‐1 μg/ml lost their chemotactic responsiveness when reexposed to the same stimulus. In conjunction with chemotactic response to the elastin‐derived peptide, intracellular guanosine 3′, 5′‐monophosphate (cGMP) levels were enhanced but intracellular adenosine 3′, 5′‐monophosphate (cAMP) levels were not. The monocyte migration induced by the elastin‐derived peptide was inhibited by cGMP dependent protein kinase (PKG) inhibitor, but not by cAMP dependent protein kinase inhibitor and protein kinase C inhibitor. These results suggest that the elastin‐derived peptide induces monocyte chemotaxis by increasing the level of cGMP, followed by activating PKG.
The growth kinetics of intracellular bacille calmette‐ guerin (BCG) within human monocyte‐derived macrophages of different ethnic populations
Authors: Fazal Nadeem 
Published: July 2007

AbstractIn this paper we have examined intracellular mycobacterial growth in human monocyte‐derived macrophage cell cultures. Cells from three population groups were selected to compare and contrast the kinetics of intracellular BCG growth both by determining changes in metabolic activity of dividing bacteria by radioisotope incorporation and growth/survival by estimating colony forming unit by Fazal's Microcolony Counting Method. These data indicate that BCG infects and multiplies intraceltularly in human macrophages and may serve as an in vitro model for studying inherent capability of mycobacteria to grow and infect macrophage populations. There is however, no inhibition or reduction of intracellular mycobacterial growth from a Caucasian male and female, and an Afrocarribean female donor macrophages. On the contrary, there is a ten‐fold increase in the replication of mycobacteria over a 7‐day infection period. Patterns of BCG growth within macrophage cultures from different donors were determined and variation calculated at different days post‐infection. Experiment to experiment coefficient of variation of intracellular BCG growth estimates for a single donor is between 4‐12%. In contrast, the coefficient of variation of intracellular BCG growth between three different macrophage donors studied is <4%.