bluuebunny/crossref_metadata_2025_split huggingface dataset:
tRNA aminoacylated at high pressure is a correct substrate for protein biosynthesis
Authors: Krzyzaniak Andrzej , Twardowski Tomasz , Barciszewski Jan , Sałanski Piotr , Jurczak Janusz 
Published: July 2007

AbstracttRNA can be aminoacylated specifically with amino acids at high pressure of 6 kbar (1 bar = 1.013 atm = 0.1 MPa = 105 Pa) in the absence of the specific aminoacyl‐tRNA synthetase and ATP. In this paper we present new evidence obtained by HPLC chromatography and TLC analysis that the esterification reaction under pressure really takes place at the 3′ end of the tRNA molecule. If so, tRNA to be aminoacylated undergoes conformational changes similar to those induced with aminoacyl‐tRNA synthetase. The most important finding is that aminoacyl‐tRNA obtained at high pressure binds to ribosomes and participates in the synthesis of polyphenylalanine in vitro. This is the best proof of proper charging of tRNA at high pressure.
Characterization of a novel DNA binding domain within the amino‐terminal region of the RAG‐1 protein
Authors: Alva Jackelyn A. , Lin Albert , Lyon Christopher J. , Aguilera Renato J. , Galic Zoran 
Published: July 2007

AbstractRag‐1 and Rag‐2 are the critical components of the V‐(D)‐J recombinase required for site‐specific recombination of the antigen receptor genes. In this study, we have examined the ability of recombinant (r) Rag‐1 and Rag‐2 to bind the recombination signal sequences (RSS) and have determined that rRag‐1, but not rRag‐2, is able to directly bind DNA. rRAG‐1 DNA binding activity was found to reside within a novel amino‐terminal arginine‐rich (RR) domain with partial homology to a variety of nucleic acid binding domains. Although the RR‐domain did not demonstrate RSS‐specificity, this DNA binding domain may stabilize the interaction of RAG‐1 with, or increase the affinity for, the V‐(D)‐J recombination signals.
Changes of isoenzymes of serum N‐acetyl‐β‐D‐glucosaminidase in relation to different types of diabetes
Authors: Mandic Ljuba , Filipovic Dragana 
Published: July 2007

AbstractThe activity of the isoenzymes of N‐acetyl‐β‐D‐glucosaminidase (NAG, EC 3.2.1.30) is determined in the serum of insulin‐dependent (IDDM) and non‐insulin‐dependent diabetics (NIDDM) with or without diabetic complications. The increase in total activity of serum NAG in diabetics is proportional to the A form activity (r=0,976, p< 0,0001). The contribution of the A form activity (65.87±5.99%) to total NAG activity of IDDM and NIDDM diabetics with and without complications does not change considerably compared to the control group. The contribution of the B form activity depends on the state of metabolic monitoring and diabetic complications. A significantly lower activity of the serum B form was found in IDDM (p<0,001) and NIDDM diabetics (p<0,05) compared to the healthy individuals, as well as the higher activity ratios of the A/B forms. A decrease in serum B form is correlated with the occurrence and abundance of the intermediary I forms (r=‐0,665). These changes are particularly significant in the individuals with the pronounced microangiopathy.
Tata element‐binding protein is important to epidermal growth factor‐dependent induction of H2B histone gene expression in primary hepatocytes from rat
Authors: Lim Kyu , Song Hea‐Jeong , Yun Kyung‐Ah , Son Mee‐Young , Park Jong‐Il , Kweon Gi‐Ryang , Hwang Byung‐Doo , Byun Sang‐Hyun , Yoon Wan‐Hee 
Published: July 2007

AbstractEpidermal growth factor (EGF) is a potent mitogen for rat hepatocytes and mammalian histone synthesis is functionally and temporally coupled to DNA replication. To gain an insight on the role of EGF in the regulation of H2B histone gene expression in primary hepatocyte cultures, the binding patterns of nuclear proteins to various elements in the H2B histone gene upstream region have been investigated. EGF induced H2B histone mRNA with maximal stimulation reached at 36 hours. The induction of H2B histone mRNA was dependent on the concentration of EGF and almost reduced by actinomycin‐D pretreatment. In DNase I footprinting analysis, one nuclear factor (TATA element‐binding protein, TBP) bound at ‐20 bp (TATA element)in either the absence or presence of EGF. One DNA‐protein complex was formed by DNA mobility shift assay when TATA element was incubated with nuclear extract prepared from EGF‐free hepatocytes, and the amount of TBP was increased after EGF treatment. These results suggest that TBP may be correlated with transcriptional regulation of H2B histone gene by EGF in primary hepatocytes.
Development of a competitive enzyme linked immuno sorbent assay to measure ceruloplasmin in γ‐irradiated rat serum
Authors: Kim In Gyu , Park Seon Young , Kim Kug Chan 
Published: July 2007

AbstractThe concentrations of ceruloplasmin could not be determined by comparing the oxidase activities toward p‐phenylenediamine and o‐dianisidine in rat whole serum with those of purified ceruloplasmin because of the different specific amine oxidase activities of ceruloplasmin purified from normal and γ‐irradiated rats and the lability caused by freezing and thawing. A competitive enzyme linked immunosorbent assay with antigens immobilized on the solid phase was developed to measure the ceruloplasmin in rat serum. The blocking materials and pH of the coating buffer had an effect on the amount of ceruloplasmin bound to the microtiter plates. The blocking materials nonspecifically reacted with the rabbit anti‐rat ceruloplasmin IgG, and consequently the coating sensitivity was decreased and standard curves were not formed completely. Because rabbit anti‐rat ceruloplasmin IgG did not show any cross reactivity with rat albumin and hemoglobin, these proteins did not affect the assay at a concentration of 200 μg/ml. This assay is useful for measuring the concentration of ceruloplasmin in normal and irradiated rat serum.
A convenient method of DNA extraction from blood anticoagulated wity EDTA
Authors: Yokota M. , Sindo K. , Hiyoshi M. , Tsuda I. , Tatsumi N. 
Published: July 2007

AbstractSurplus blood often remains after routine clinical tests using EDTA‐anticoagulated samples. To use this blood for DNA analysis, we isolated white cells by adherence to polyethylene terephthalate fibers, which could be stored for several weeks transported by mail after methanol fixation. DNA yield was sufficient and correlated with white cell count. Extracted DNA was free of hemoglobin contamination and durable to polymerase chain reaction and enzyme digestion, which yielded products visualized as well‐separated bands on electrophoresis. We found our method to be practical for the routine clinical laboratory.
Amplification of phenylalanine hydroxylase and cystathionine β‐synthase transcripts in human peripheral lymphocytes by RT‐PCR
Authors: Devi K. Santhi , Devi A. Radha Rama , Kondaiah Paturu 
Published: July 2007

AbstractA simple, rapid, reliable and convenient method was developed to analyze the gene defects in Phenylketonuria (PKU) and Homocystinuria (HCU). In this method, illegitimately transcribed phenylalanine hydroxylase (PAH) and cystathionine β‐synthase (CBS) mRNAs in peripheral lymphocytes were used as templates for amplification by RT‐PCR. The amplified products were confirmed by restriction enzyme digestions, southern blot hybridizations and sequencing. Point mutations in the protein coding region and splice junction mutations of PAH and CBS can be analyzed by this method.
De novo protein synthesis is essential for thermotolerance acquisition in a Saccharomyces cerevisiae trehalose synthase mutant
Authors: Gross Claudia , Watson Kenneth 
Published: July 2007

AbstractHeat shock (25°C to 37°C for 30 min) acquisition of thennotolerance (at 50°C) was observed in a yeast trehalose synthase mutant and the corresponding control strain. The acquisition of thermotolerance in the control strain was maintained for a significantly longer time in the trehalose synthase mutant. The heat shock was associated with the synthesis of specific heat shock proteins and, in the case of the control strain, also trehalose accumulation. Inhibition of protein synthesis during the heat shock totally abolished acquisition of thermotolerance in both strains but not trehalose accumulation in the control. It was concluded that trehalose may only be required for prolonged stress protection while heat shock proteins are required for heat shock acquisition of thermotolerance.
DNA‐binding properties of the overexpressed recombinant estrogen receptor α
Authors: Ikeda Mitsunori , Tsuji Norio , Kikukawa Kyoko , Asahar Yoshie , Nakashima Aya , Minatogawa Yohsuke 
Published: July 2007

AbstractEstrogen receptor α was overexpressed in COS‐7 cells by transformation of an expression vector with the full length open reading frame of the receptor α. The nuclear estradiol‐receptor complex and the soluble receptor from the COS‐7 cells were cross‐linked with an estrogen response element (ERE), which was substituted with 5‐bromo‐2′‐deoxyuridine (BrdUVRE), as the receptor dimers by UV irradiation. In gel retardation analysis, the specific bindings of both nuclear and soluble receptors to ERE were decreased with increasing of KCl concentration compared with 0.1 M KCl. The ionic interactions of both receptors with ERE are thought to be similar.
Cloning and expression analysis of a cDNA coding for a dexamethasone‐inducible cytochrome P450 in Xenopus laevis liver
Authors: Ohi Hiroaki , Sugata Eiji , Fujita Yoshiaki , Saito Hiromi , Saguchi Ken‐ichi , Murayama Nobuhiro , Higuchi Shigesada 
Published: July 2007

AbstractWe previously purified a cytochrome P450 (P450) from liver microsomes of adult female Xenopus laevis. In this study, we screened a cDNA library of Xenopus liver to isolate the cDNA clone coding for this P450. The 5′‐end of the resultant cDNA was truncated at the N‐terminal region and extended by method of rapid amplification of eDNA end to give the complete coding sequence. Amino acid sequence showed this clone to be 36% to 55% identical to members of the CYP2 family and less than 31% identical to members of other gene famines, and to belong to the CYP2Q subfamily. This gene is expressed constitutively in the livers of adult male and female frogs, and is significantly induced by dexamethasone administration.
Possible target components for the inhibitory effect of N‐ethylmaleimide on the activation of neutrophil NADPH oxidase
Authors: Park Jeen‐Woo , Park Hee‐Sae , Lee Su Min 
Published: July 2007

AbstractPotential target components for the inhibitory effect of covalent sulfhydryl‐modifying reagent N‐ethylmaleimide (NEM) on the activation of NADPH oxidase in human neutrophils was studied in a cell‐free system. The capacity of both cytosol and membrane fractions to induce the translocation of cytosolic components and O2‐ generation in the cell‐free activation system was affected by NEM. The phosphorylation of p47phox, which mediates the translocation of cytosolic complex, by protein kinase C was not inhibited by NEM and NEM‐treated p47phox was as effective as untreated p47phox both in the kinase‐dependent and in the amphiphile‐dependent cell‐free activation sysyems. In addition, phosphatidic acid‐dependent phosphorylation of cytosol including p47phox was not affected by NEM. The inhibition of cytosol's capacity to activate NADPH oxidase was partially reversed by an addition of the fraction containing G‐protein rac. Taken together, the data suggest that membrane component cytochrome b558 and cytosolic component rac may be the potential targets for the NEM effect on the activation ofNADPH oxidase.
Streptokinase secretion by Serratia marcescens signaled by the C‐terminal 41 amino acid segment of metalloprotease
Authors: Kim Ki Seok , Bae Kwang Hee , Kim Il Chul , Byun Si Myung , Shin Yong Chul 
Published: July 2007

AbstractIn order to investigate the secretion signal of Serratia marcescens metalloprotease (SMP) and examine the ability of the secretion signal to secrete foreign proteins, hybrid genes encoding the passenger‐SMP C‐terminal segments were constructed. As a passenger protein, streptokinase (SK) deprived of its signal peptide was used. Three kinds of SMP C‐terminal segments containing 41, 80, or 220 amino acid residues were fused to the C‐terminus of SK as secretion signals. The SK‐SMP chimeric proteins containing 41 or 220 amino acid segments of the SMP C‐terminus were secreted into the culture medium by the SMP transporter of S. marcescens. This result suggests that cytoplasmic SK is secreted into the external medium by the C‐terminal segments of SMP and also shows that the smallest, 41 amino acid segment of the SMP C‐terminus functions as a secretion signal of foreign proteins as well as SMP.
Altered membrane skeleton of red blood cells participates in cadmium‐induced anemia
Authors: Hamada Tetsuo , Tanimoto Akihide , Arima Nobuyuki , Ide Yoshihiro , Sasaguri Takakazu , Shimajiri Shohei , Sasaguri Yasuyuki 
Published: July 2007

AbstractPoikilocytosis of red blood cells (RBCs) was observed to be associated with anemia in rats given subcutaneous injections of cadmium (Cd). Phase‐contrast light and scanning electron microscopic examinations revealed that acanthocytes appeared in the early stages of administration, and that the number of RBC fragments increased later. Ultrastructural analysis of RBC ghosts by negative staining demonstrated that the normal lattice structure of the membrane skeleton was abolished. The osmotic fragility curve of the Cd‐exposed RBCs disclosed that most of the cells were less fragile than control RBCs. These data indicate that the RBC membrane skeleton is initially altered by Cd‐exposure, followed by deformation of the cell, thus promoting intrasplenic hemolysis, and resulting in anemia.
Neonatal hyperbilirubinemia and mutation of the bilirubin uridine diphosphate‐glucuronosyltransferase gene: a common missense mutation among Japanese, Koreans and Chinese
Authors: Akaba Kazuhiro , Kimura Toshiyuki , Sasaki Ayako , Tanabe Saori , Ikegami Tohru , Hashimoto Motoya , Umeda Hitoshi , Yoshida Hiroshi , Umetsu Kazuo , Chiba Hitoshi , Yuasa Isao , Hayasaka Kiyoshi 
Published: July 2007

AbstractWe analyzed the bilirubin uridine diphosphate‐glucuronosyltransferase (B‐UGT) gene in 42 Japanese newborns with hyperbilirubinemia and determined that 21 infants were heterozygous while 3 was homozygous for Gly71Arg. Allele frequency of Gly71Arg was 0.32 in newborns with hyperbilirubinemia, which was significantly higher than 0.13 in healthy Japanese controls. This mutant allele is also prevalent among Korean and Chinese healthy controls with a frequency of 0.23 in both populations. However, this mutation was not detected in 50 healthy German controls. These data suggest that the high frequency of the Gly71Arg mutation of the B‐UGT gene is associated with high incidence of neonatal hyperbilirubinemia in Japanese, Korean and Chinese populations.
EPC‐K1 attenuates peroxynitrite‐induced apoptosis in cerebellar granule cells
Authors: Wei Taotao , Chen Chang , Zhao Baolu , Xin Wenjuan , Mori Akitane 
Published: July 2007

AbstractApoptosis induced by peroxynitrite in cultured cerebellar granule cells was confirmed morphologically by chromatin condensation and biochemically by DNA laddering. A 30 min exposure to peroxynitrite (10 μM) initiated oxidative stress, which caused the formation of thiobarbituric acid‐reactive substances (TBARS) and the alteration of cell membrane fluidity. Peroxynitrite treatment also caused ATP decrease and thus activated the apoptotic program. Pre‐treating cells with antioxidant EPC‐K1 (L‐ascorbic acid 2‐[3,4‐dihydro‐2,5,7,8‐tetramethyl‐2‐(4,8,12‐trimethyltridecyl)‐2H‐1‐benzopyran‐6‐yl‐hydrogen phosphate] potassium salt), a new water‐soluble derivative of vitamin C and vitamin E, attenuated oxidative injury and prevents cells from apoptosis. The results suggest that EPC‐K1 might be used as a potential therapeutic agent for diseases associated with NO/ONOO‐‐mediated neuronal injury.
Insulin rapidly induces nuclear translocation of PI3‐Kinase in HepG2 cells
Authors: Kim Sung‐Jin 
Published: July 2007

AbstractInsulin action on nuclear PI3‐Kinase and IRS‐1 was explored in HepG2 cells. Following insulin treatment, the cells were subjected to subcellular fractionation. Western blot analyses were carried out to identify IRS‐1 and PI3‐Kinase in the nuclear and postnuclear preparations. IRS‐1 protein was identified in the nucleus under basal condition. Insulin had no effect in the content of nuclear IRS‐1. In contrast, PI3‐Kinase was not detected under basal condition. However, insulin treatment for 1 to 10 min caused significant increase of PI3‐Kinase in the nucleus while it induced corresponding decrease of PI3‐Kinase in cytoplasm. Strikingly, Insulin stimulated the association of IRS‐1 and PI3‐Kinase in the nucleus in a similar kinetics with the nuclear translocation of PI3‐Kinase. These results suggest that insulin induces nuclear tranlocation of PI3‐Kinase and the translocated PI3‐Kinase associates with nuclear IRS‐1. The association of IRS‐1 and PI3‐Kinase in the nucleus in response to insulin may play important roles in nuclear insulin actions.
Oxygen free‐radicals mediate the damaging effect of ultraviolet light on membrane mitochondria
Authors: Chávez Edmundo , Zazueta Cecilia , Cuéllar Adela , Reyes‐Vivas Horacio , García Noemí 
Published: July 2007

AbstractThis paper reports evidence that exposure of mitochondria to near‐ultraviolet light inhibits electron transport, collapses the electric gradient, and increases non‐specific membrane permeability to matrix solutes such as Ca2+. Membrane energization, as well as superoxide dismutase and catalase avoid membrane leakiness. Increased permeability correlates with a diminution in the titrated thiol groups. Plausibly the pore is formed through the formation of sulfhydryl bridges by the action of UV light‐derived oxygen‐centered free‐ radicals on membrane proteins.
An essential lysine residue of green crab (Scylla Serrata) alkaline phosphatase
Authors: Chen Qing‐Xi , Zhou Hai‐Meng 
Published: July 2007

AbstractThe values of pKa (10.38) and Hion (10.92 Kcal/mol) have been determined for the ionizing groups controlling activity of green crab alkaline phosphatase. The results suggest that ‐NH2 of lysine residue responsible for the ionzation with pKc=10.38 and ΔH° is in the active site of the enzyme. Modification of lysine residues of the enzyme by an excess of 2,4,6‐trinitrobenzenesulfonic acid leads to complete inactivation. The two results coincide with each other. Quantitative assessment of the data indicates that among the reactive ‐NH2 groups modified only one is essential for the activity of the enzyme.
The DNA sequence specificity of hedamycin damage determined by ligation‐mediated PCR and linear amplification
Authors: Cairns Murray J. , Murray Vincent 
Published: July 2007

AbstractThe DNA sequence specificity of hedamycin damage was compared using two techniques: Ligation‐mediated PCR (LMPCR) and Linear Amplification (LA). The electrophoretic mobility of LA products were made comparable with LMPCR products by using a primer with a 27 bp non‐binding 5′‐extension. By direct comparison of the damage intensity (as represented by each of the methods), considerable bias was found in the LMPCR system with respect to LA‐resulting in the under representation of lesions with T as the base 3′ to the damage site. In view of this observation some caution should be exercised in the interpretation of data for DNA damage/repair specificity derived by LMPCR. In addition the extended primer LA method used in these experiments, could be applied to generate a dideoxy sequencing ladder for analysis of LMPCR products. This would negate the need to prepare Maxam‐Gilbert chemical sequencing fragments for amplification through LMPCR.
Increased metabolism of peroxynitrite‐modified [125I] β‐VLDL by monocytes from hypercholesterolemic rabbits
Authors: Silva E.L. da , Abdalla D. S. P. 
Published: July 2007

AbstractThe metabolism (uptake and degradation) of peroxynitrite‐modified β‐VLDL and native β‐VLDL labeled with [125I]iodine was studied in monocytes isolated from peripheral blood of hypercholesterolemic (HC) and normolipidemic rabbits (NC). The peroxynitrite‐modified β‐VLDL uptake and degradation was up to 2‐fold higher in monocytes from HC rabbits than monocytes from NC rabbits. In addition, monocytes from HC rabbits took up and degraded significantly more peroxynitrite‐modified β‐VLDL than native β‐VLDL. In contrast, monocytes from NC rabbits took up both lipoproteins in a similar rate and degraded more native β‐VLDL than peroxynitrite‐modified β‐VLDL. Our results suggest that hypercholesterolemia can affect monocyte metabolism enhancing foam cell formation by increasing the influx of peroxynitrite‐modified β‐VLDL.
Changes in the activities of mitochondrial enzymes in the progress of tumorigenesis of bladder cancer
Authors: Huang Chun‐Nung , Tsai Jin‐Lian , Chen Ming‐Tan , Wu Wen‐Jeng , Kuo Kou‐Wha , Huang Chun‐Hsiung 
Published: July 2007

AbstractTo investigate changes in the activities of mitochondrial enzymes in the progress of tumorigenesis of bladder cancer, N‐butyl‐N‐(4‐hydroxybutyl) nitrosamine (BBN) carcinogen was administered orally to male Sprague‐Dawley rats for eight weeks. The urinary bladders were harvested periodically for the evaluation of tumorigenesis. The activities of NADH cytochrome c reductase (NCCR), succinate cytochrone c reductase (SCCR) and cytochrome c oxidase (CCO) were measured. The NCCR and SCCR activities elevated significantly by the exposure of BBN and decreased rapidly when BBN was withdrawn. However, the CCO activity increased and reached plateau at 18 weeks in spite of the discontinuance of BBN. The results indicated that the NCCR, SCCR and CCO activities were significantly elevated in the tumorigenesis. However, the CCO enzyme may be more related to the progress of tumorigenesis of bladder cancer.
The interfacial behavior of cytochrome c studied by pendant‐drop technique
Authors: Gazová Zuzana , Bágelová Jaroslava , Antalík Marián , Tomori Zoltán 
Published: July 2007

AbstractThe adsorption properties of cytochrome c (cyt c) were characterized by surface tension measurements using the pendant‐drop method employing the digital image analysis of the drop shape. The method was applied to the study of the protein conformation change due to acidification at low ionic strength. The observation of the saturated steady‐state surface tension shows that decrease in pH induces its cooperative change centered around pH 2.5. This value is equal to the value of apparent pK of the acid‐induced transition of the horse ferricyt c from a native state to the unfolded conformation. This indicates that the saturated steady‐state surface tension is sensitive to the conformation of cyt c in bulk phase, and the pendant‐drop method might be used to monitor changes in the tertiary structure of proteins.
Molecular cloning and analysis of the argC gene from Corynebacterium glutamicum
Authors: Chun Jae‐Yeon , Lee Eun‐Jung , Lee Heung‐Shick , Cheon Choong‐Ill , Min Kyung‐Hee , Lee Myeong‐Sok 
Published: July 2007

AbstractThe argC gene encoding N‐acetylglutamate 5‐semialdehyde dehydrogenase has been cloned from Corynebacterium glutamicum by transforming Escherichia coli arginine auxotroph with the genomic DNA library. Based on the restriction map of the cloned DNA, we have subcloned and sequenced the minimal DNA fragment complementing the E. coli argC mutant. The coding region of the cloned gene is 1041 nucleotides long with a predicted molecular mass of about 38 kDa polypeptide. Enzyme activity and size of the expressed protein in the E. coli auxotroph carrying the recombinant argC gene revealed that the cloned gene indeed codes for N‐acetylglutamate 5‐semialdehyde dehydrogenase. Computer analysis of the amino acid sequences of the predicted protein revealed a strong similarity to the corresponding protein of other bacteria.