bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene encoding a human testis sertoli cell component related to LIM domain protein
Authors: Yang J. X. , Miao S. Y. , Wu Y. W. , Zhang Z. , Zong S. D. , Wang L. F. , Koide S. S. 
Published: July 2007

AbstractThe cDNA (HED‐2) encoding a 20 kDa protein found in mammalian epididymal fluid was isolated from a human testis expression library. It is composed of 1908 bp, containing a reading frame of 1479 bp, coding a polypeptide consisting of 493 amino acids, and assigned the accession number: U 15158 by GenBank (Biochem. Mol. Biol. Int. 34, 1131‐1136, 1994). HED‐2 has 99% identity with the zyxin gene in amino acid sequence, a component of cell junction matrix and a member of the LIM domain protein family. Northern blot analysis of RNAs prepared from various human tissues showed that the HED‐2 gene was expressed in all tissues analyzed. Sertoli cells of human testis expressed the gene as determined by an in situ hybridization method. The present study shows that the HED‐2 gene is a member of the LIM domain protein family.
Purification and characterization of sucrose synthase isozymes from etiolated rice seedlings
Authors: Huang Der‐Yi , Wang Ai‐Yu 
Published: July 2007

AbstractPresence of homo‐ and hetero‐tetrameric rice sucrose synthase (RSS) isoforms in etiolated rice seedlings was demonstrated by immunoprecipitation using monospecific antibodies. Three RSS isozymes with various pI values were purified by ammonium sulfate fractionation, Sepharose CL‐6B gel filtration, DEAE‐Sephacel and Mono‐Q ion exchange chromatographies. They were characterized as heterotetramers composed of RSS1 and RSS2 subunits. All of them used UDP as the best substrate. The presence of divalent metal ions increased the activities of synthesis but inhibited the cleavage of sucrose.
HIV‐1 Nef protein causes death in stressed yeast cells due to determinants near the N‐terminus and elsewhere in Nef
Authors: Macreadie I. , Sankovich S. , Failla P. , Lowe M. , Curtain C. , Castelli L. , Azad A. 
Published: July 2007

AbstractThe Human Immunodeficiency Virus type 1 (HIV‐1) Nef protein is essential for AIDS pathogenesis. In order to determine more about the effects of Nef on basic cellular functions Nef was produced in yeast under a variety of conditions and in multiple cell types. Production of Nef caused cell death in acutely copper‐ or heat‐stressed diploid cells. The N‐terminal melittin‐like region of Nef was involved in toxicity since a Trp5→Ala change within Nef change caused increased toxicity. However, another determinant was also involved in toxicity since production of Nef20‐206 was also still toxic. In each of these Nef‐producing cells there was coincident membrane permeabilisation. These results suggest the possibility of a novel yeast bioassay for Nef inhibitors and that cells producing high levels of Nef may be selectively killed by stress.
Crystallization, preliminary x‐ray analysis and patterson search of a new aspartic protease isolated from human urine
Authors: Canduri Fernanda , Teodoro Lívia G. V. L. , Lorenzi Carla C. B. , Gomes Roseli A. S. , Fontes Marcos R. M. , Arni Raghuvir K. , de Azevedo Walter F. 
Published: July 2007

AbstractAspartic protease (EC 3.4.23) make up a widely distributed class of enzymes in animals, plants, microbes and, viruses. In animals these enzymes perform diverse functions, which range from digestion of food proteins to very specific regulatory roles. In contrast the information about the well‐characterized aspartic proteases, very little is known about the corresponding enzyme in urine. A new aspartic protease isolated from human urine has been crystallized and X‐ray diffraction data collected to 2.45Å resolution using a synchrotron radiation source. Crystals belong to the space group P212121. The cell parameters obtained were a=50.99, b=75.56 and c=89.90 Å. Preliminary analysis revealed the presence of one molecule in the asymmetric unit. The structure was determined using the molecular replacement technique and is currently being refined using simulated annealing and conjugate gradient protocols.
The role of proline in the prevention of aggregation during protein folding in vitro
Authors: Kumat T. K. S. , Samuel D. , Jayaraman G. , Srimathi T. , Yu C. 
Published: July 2007

AbstractProline effectively inhibits protein aggregation during the refolding of bovine carbonic anhydrase. Other osmolytes used such as glyeine and ethylene glycol fail to exhibit the ‘aggregation‐blockade’ role shown by proline. Results of viscosity and ANS fluorescence (1‐anilino‐8‐naphthalene sulphonic acid) experiments suggest that proline at high concentrations forms an ordered supramolecular assembly. Based on these results, it is proposed that proline behaves as a protein folding chaperone due to the formation of an ordered, amphipathic supramolecular assembly. To our knowledge, this is the first report wherein proline is proposed as a protein folding aid.
Regulation of Na,K‐ATPase activity in renal basolateral membrane of 1‐clip‐1‐kidney hypertensive rat
Authors: Seok Jeong‐Ho , Kim Ju‐Byoung , Hong Jang‐Hee , Sung Ji‐Yeon , Hur Gang‐Min , Lim Kyu , Lee Jae‐Heun 
Published: July 2007

AbstractThe changes of Na,K‐ATPase activity and its regulation have been investigated in the renal cortex of 1‐clip‐1‐kidney hypertensive rat. Ouabain‐sensitive Na,K‐ATPase activity (Emax) and [3H]ouabain‐binding site (Bmax) in the hypertensive rat were slightly increased than those in the control. The levels of Na,K‐ATPase α1‐ and β1‐subunit mRNA of the renal cortex in hypertensive rat were more increased than those in the control. Their increases were repressed by actinomycin‐D, but not altered or more increased by cycloheximide. These results suggest that the increase of Na,K‐ATPase activities and ouabain binding sites in 1‐clip‐1‐kidney hypertensive rat may be correlated with the increases of gene expression in transcription level and/or of mRNA stability of Na,K‐ATPase.
Isolation of the genomic clone of the rhesus monkey beta‐amyloid precursor protein
Authors: Songa Weihong , Lahiri Debomoy K. 
Published: July 2007

AbstractA change in the regulation of the beta‐amyloid precursor protein (βAPP) gene may be a factor for Alzheimer's disease (AD). We have screened a rhesus monkey genomic library and pulled out a ∼17 kb genomic DNA region which contains the 5′‐flanking region (promoter), first exon and intron of the βAPP gene of the Rhesus monkey (rhβAPP). We have partially characterized the genomic clone by selective restriction enzyme digestion followed by Southern blotting against the βAPP gene‐specific DNA probes. The identity and authenticity of the different bands of the clone were also confirmed by Southern blot analysis of the rhesus monkey genomic DNA. Functional identification of the genomic fragment was determined by a promoter assay using the chloramphenicol acetyltransferase (CAT) enzyme as a reported gene. Our results showed that a 1.2 kb fragment from the 5′‐flanking region of the rhβAPP gene possessed strong promoter activity. The isolation of this genomic clone will enable characterization of the structure and function of the promoter of the rhβAPP gene. Our initial results indicate a high degree of homology between the structure of the rhesus monkey and human βAPP promoter.
Membrane perturbation by the neurotoxic alzheimer amyloid fragment β25‐35 requires aggregation and β‐sheet formation
Authors: Hirakura Yutaka , Satoh Yasushi , Hirashima Naohide , Suzuki Toshiharu , Kagan Bruce L. , Kirino Yutaka 
Published: July 2007

AbstractThe β‐amyloid peptide (βAP) is a major proteinaceous component of senile plaques and cerebrovascular amyloid deposits found in the brain of patients with Alzheimer's disease. βAP is reported to be neurotoxic only when it forms β‐sheet structure and aggregates. In the present study, we report that the neurotoxic core of βAP, βAP‐25‐35 (β25‐35), perturbs liposome membranes, induces membrane current, and exhibits hemolytic activity only in a buffer condition where the peptide forms β‐sheet structure and spontaneously aggregates. In contrast, β25‐35 in its monomeric random coil structure does not perturb lipid membranes significantly, and exhibits no hemolytic activity. Also, the membrane current was inhibited by Congo Red. The ability of β25‐35 to interact with membranes highly correlates with its neurotoxicity reported previously. These results suggest that membrane perturbation by aggregated β25‐35 constitutes the molecular basis of the peptide's neurotoxicity.
The plasma membrane Fe3 ‐reductase activity of Caco‐2 cells is modulated during differentiation
Authors: Ekmekcioglu Cem , Strauss‐Blasche Gerhard , Marktl Wolfgang 
Published: July 2007

AbstractThe aim of the present study was to investigate whether the brush border membrane ferric reductase activity of Caco‐2 cells is modulated during cell differentiation. The ferric reductase activity was determined in whole cells and isolated microvillous membranes at different stages of cell differentiation by measuring the amount of Fe3+ reduced during the incubation time. Our results indicated that the ferric reductase activity decreased in fastly growing cells and reactivated in postconfluent cells in contrast to the alkaline phosphatase and sucrase activities which were progressively expressed during differentiation as conventional indicators of cell maturity. The lowest ferric reductase activity was found in cells at the log phase of proliferation, while freshly seeded or highly differentiated cells had significantly higher enzyme activities. Cells grown under serum‐free conditions had similar ferric iron reduction rates as cells propagated under standard conditions. Reagents or hormones affecting cell metabolism through different pathways had no significant effect on this transplasma membrane redox system.
Inhibition of wheat leaves nitrate reductase activity by Cibacron Blue
Authors: Albassam Badr A. 
Published: July 2007

AbstractCibacron Blue F3GA (CB) inhibited the activities of wheat leaves NADH:nitrate reductase and NADH:cytochrome‐c reductase in a time‐independent and concentration dependent manner. The methyl viologen:nitrate reductase activity of the enzyme was unaffected by various CB concentrations used in the experiment. Inhibition of NADH:nitrate reductase was of mixed type (partial competitive and pure noncompetitive) with respect to NADH and noncompetitive with respect to nitrate. The estimated inhibition constant (Ki) values were 1 μM for NADH and 8.4 μM for nitrate. The secondary plots of inhibition with respect to NADH, indicated a dissociation constant (K1) of 8.8 μM for the enzyme‐NADH‐CB complex. This K1 being greater than the Ki suggested that the noncompetitive inhibition is predominant over the competitive inhibition at the NADH binding site.
An inverted cAMP response element mediates the cAMP induction of the ovine β1‐adrenergic receptor gene
Authors: Tseng Yi T. , Stabila Joan , McGonnigal Beth , Nguyen Tien T. , Padbury James F. 
Published: July 2007

AbstractWe identified an inverted, functional cAMP response element (CRE) located at ‐1599 bp relative to the translation start site within the ovine β1‐adrenergic receptor (β1AR) gene promoter. In transfection studies with SK‐N‐MC cells, a 40‐bp oligonucleotide containing the potential CRE, β1AR‐CRE, conferred a 3‐ to 4‐fold increase in luciferase activity mediated by cAMP. The induction was mimicked by co‐transfecting the cells with a vector overexpressing the α‐catalytic subunit of the cAMP‐dependent protein kinase (PKA) without treatment, and was blocked by overexpressing a PKA inhibitor (PKI). In electrophoretic mobility shift assays, a discrete binding pattern was shown in cell nuclear extract probed with the 40 bp β1AR‐CRE. The binding was shown to be specific and supershifted by addition of a CRE binding protein (CREB‐1) antibody. These data demonstrate that cAMP mediates the induction of β1AR gene expression by interacting with an inverted CRE within the promoter region. This is the first reported functional CRE among all β1AR genes.
Cloning of the genomic sequence encoding a processed adenylate kinase 2 pseudogene
Authors: Lee Younghee , Hong Mihui , Kim Yeon Jung , Kim Jae Wha , Kim Cheorl Ho , Lee Kwang Soo , Chang Sung Yeoul , Lim Jong‐Seok , Choe In Seong 
Published: July 2007

AbstractA chromosomal DNA sequence harboring a processed AK2B pseudogene was isolated from a human genomic library. It was a variant of the AK2B gene sequence including several point mutations, deletions, and insertions. The nuclcotidc sequence of the ORF of the AK2B pseudogene predicted a truncated form of the AK2B mutant suggesting that the processed pseudogene is nonfunctional. A repetitive sequence, AAAAGAGAG, found in the 5′ and 3′ flanking regions of the pseudogene and the poly(A) tract in the 3′ end junction suggest that a mRNA of AK2B may have been converted to the processed pseudogene by retrotransposition events. Previously, it was suggested that an adenylate kinase (AK) 2 related gene on chromosome 2, confirmed by Southern analysis using somatic cell hybrid cell lines, may be a processed pseudogene. It is proposed that the processed pseudogene isolated in this study may be the AK2 related nonfunctional gene localized on human chromosomes 2.
Roles of nitrate, nitrite and ammonium ion in phytochrome regulation of nitrate reductase gene expression in maize
Authors: Raghuram Nandula , Sopory Sudhir K. 
Published: July 2007

AbstractThe influence of nitrate and its metabolites on the nitrate reductase (NR) gene expression and its relationship with phytochrome (Pfr) regulation of NR in etiolated maize leaves is examined. Nitrate induction and Pfr stimulation are brought about by independent signalling phenomena. Phorbol myristate acetate (PMA), a stimulator of protein kinase C (PKC), mimicked the effect of red light but could not replace the nitrate requirement for the induction of NR transcript accumulation. This suggests that while PKC‐type enzymes may be involved in mediating the Pfr signal, nitrate may follow an independent signalling mechanism. Experiments with 5‐hydroxytryptamine (5HT) and lithium ions (Li+), which are known to modulate phosphoinositide (PI) turnover, indicated that in addition to generating Pfr‐induced second messengers for PKC activation, PI cycle may also generate other signals which mediate nitrate induction of NR gene expression in the dark. The products of nitrate reduction ie, nitrite and ammonium ion had inhibitory and stimulatory effects respectively, on NR transcript accumulation. They work mainly at the level of nitrate induction.
High level expression of soluble angiogenin in Escherichia coli
Authors: Yoon Jong Myung , Kim Seung Ho , Kwon Oh Byung , Han Seung Hee , Kim Byong Kak 
Published: July 2007

AbstractHuman angiogenin was genetically engineered and contained the E. coli Omp A signal sequence for secreting soluble angiogenin to the periplasm under tac promoter control. The angiogenin sequence was encoded in a single gene and expressed as a 14.4 kilodalton soluble protein in E. coli. It was purified by CM‐Sepharose ion‐exchange chromatography and by a heparin‐Sepharose affinity chromatography procedure. The biological activity of angiogenin was established by its ability to inhibit mRNA‐dependent rabbit reticulocyte cell‐free translation.
Hepatitis B virus: DNA polymerase activity of deletion mutants
Authors: Kim Younhee , Hong Young Bin , Jung Guhung 
Published: July 2007

AbstractThe hepadnavirus P gene product is a multifunctional protein with priming, DNA‐and RNA‐dependent DNA polymerase, and RNase H activities. Nested N‐ or C‐terminal deletion mutations and deletions of domain(s) in human HBV polymerase have been made. Wild‐type and deletion forms of MBP‐fused HBV polymerase were expressed in E. coli, purified by amylose column chromatography, and the DNA‐dependent DNA polymerase activities of the purified proteins were compared. Deletion of the terminal protein or spacer regions reduced enzyme activity to 70%, respectively. However, deletion of the RNase H domain affected polymerase activity more than that of the terminal protein or spacer region. The polymerase domain alone or the N‐terminal deletion of the polymerase domain still exhibited enzymatic activity. In this report, it is demonstrated that the minimal domain for the polymerizing activity of the HBV polymerase is smaller than the polymerase domain.
Optical biosensor studies on the productive complex formation between the components of cytochrome P450scc dependent monooxygenase system
Authors: Ivanov Yuri D. , Usanov Sergey A. , Archakov Alexander I. 
Published: July 2007

AbstractThe formation of individual complexes between the components of cholesterol side chain cleavage system ‐ cytochrome P450scc, adrenodoxin (Ad) and adrenodoxin reductase (AdR) was kinetically characterized and their association and dissociation rate constants were measured by optical biosensor. The dominant role of interprotein electrostatic interactions in productive complex formation was demonstrated. Despite of the fact that P450scc and AdR compete for the binding with the same or closely placed negatively charged groups on the surface of immobilized Ad, the formation of the AdR/P450scc/Ad ternary complex upon AdR immobilization on dextran was registered. It is shown, that Ad does not bind to AdR immobilized via amino groups AdRim but it is possible only after the preliminary binding of P450scc to AdRim. The life time of such ternary complex, about 15 s, is sufficient for the realization of 5‐8 catalytic cycles.
Age‐dependent change in arachidonic acid metabolic capacity in rat alveolar macrophages
Authors: Chakraborti Tapati , Mandal Malay , Das Sudip , Chakraborti Sajal 
Published: July 2007

AbstractArachidonic acid (AA) metabolism was assessed in cultured alveolar macrophages (AM) obtained from newborn (10 days old) and adult (2 months and 4 months old) rats. The AMs were stimulated with the calcium ionophore, A23187 (10μM). The released radiolabelled AA metabolites were measured by thin layer chromatography. The results showed that among different aged rats, the synthesis of 5‐1ipoxygenase (5‐LO) metabolites, LTB4, LTC4, LTD4 and 5‐HETE were increased with age inspite of similar levels of [14C]AA release. In response to A23187, 5‐LO metabolic capacity of 2 and 4 months old adult rat AMs were increased 21‐fold and 34‐fold, respectively, compared with 10 days old rat AMs. As the metabolic capacity increased, the release of prostaglandins and thromboxane B2 tended to decrease markedly. Newborn rats (10 days old) AM, at the initial developmental stage, did not produce a noticeable amount of 5‐LO metabolites which, conceivably, contribute to high susceptibility of neonatal lung to infection.
Glutamate release is involved in PAF‐increased cyclic GMP levels in hippocampus
Authors: Calcerrada M. C. , Catalan R. E. , Martínez A. M. 
Published: July 2007

AbstractThe involvement of glutamate in PAF‐increased cyclic GMP levels was studied. Glutamate treatment caused a dose‐response increase of cyclic GMP levels in hippocampal slices. The presence of 1 mM glutamate did not modify the effect caused by 10‐7M PAF. To elucidate the involvement of glutamate in this action, slices were treated with PAF in the presence of MK‐801, a NMDA receptor antagonist. Results indicate that PAF‐increased cyclic GMP levels were obtained by NMDA receptors activation. Finally, results obtained from the experiments performed with PAF in the presence of riluzole, to inhibit the glutamate release, demonstrated that glutamate release is a stage in the PAF‐induced increase of cyclic GMP levels in hippocampus.
Immunosuppressive effects of the heat shock protein 90‐binding antibiotic geldanamycin
Authors: Sugita Takahisa , Tanaka Sumiko , Murakami Takanori , Miyoshi Hidetaka , Ohnuki Tetsuo 
Published: July 2007

AbstractAnsamycin antibiotic, geldanamycin has a unique pharmacological effect to bind to heat shock protein 90 (hsp90) and deplete hsp90 substrates. We investigated the immunopharmacological effects of geldanamycin. Geldanamycin depleted cellular Raf‐1 of rat splenic cells without affecting the steady state levels of hsp90 and downstream mitogen activated protein (MAP) kinases, ERK1 and ERK2. In parallel, it inhibited mitogen‐induced nuclear factor‐kappa B (NF‐κB) activation in these cells. Geldanamycin also had a potent suppressive effect on recall antigen‐induced T cell proliferation, with an IC50 value of 1 nM. In vivo, geldanamycin suppressed the progression of adjuvant‐induced arthritis dose‐dependently. These results suggest that geldanamycin exerts an immunosuppressive effect partly through destabilizing Raf‐1, and raise a new strategy for the prevention of inflammatory diseases.
Expression of a novel chimeric protein containing the a chain of tissue‐type plasminogen activator and the B chain of pro‐urokinase in insect cells using the baculovirus system
Authors: Zhao Chun‐mei , Zhang Hong‐tao , Hu Mei‐hao 
Published: July 2007

AbstractA hybrid cDNA tu‐pa, which contains Serl‐Thr263 of tissue‐type plasminogen activator (t‐PA) and Ser138‐Leu411 of pro‐urokinase (pro‐UK) was constructed and expressed in the Sf9‐AcNPV system. The expression level was approximate 2.5 mg/L. Tu‐PA was purified via one‐step affinity column conjugated with monoclonal antibody against the B chain of pro‐UK, which showed a single band of approximate 60kDa in SDS‐PAGE. The specific activity of the chimeric protein on fibrin plate was 200,000IU/mg protein. Tu‐PA had a higher selectivity for fibrin than UK and pro‐UK. Its activity can be promoted by CNBr degraded fibrin fragments as t‐PA.
RAPD profile based genetic characterization of chemotypic variants of Artemisia annua L.
Authors: Sangwan R. S. , Sangwan N. S. , Jain D. C. , Kumar S. , Ranade S. A. 
Published: July 2007

AbstractThe annual herbaceous plant, Artemisia annua L., belonging to family Asteraceae, is the natural source of the highly potent antimalarial compound, artemisinin, besides producing valuable essential oil. The plant is at present the sole commercial source for artemisinin production since all the chemical syntheses are non‐viable. Therefore, economic and practical considerations dictate that plants with maximum content of artemisinin be found and/or ways to increase their artemisinin content be sought. The key to this selection and breeding is a comprehension of chemical and genetic variability and suitable selection(s) of elites from within the available population. In the present study, RAPD analyses of selected chemotypes from a decade old introduced population in India were carried out using arbitrary primers. The RAPD data clearly indicate the distinction amongst these plants. Further, the detection of highly polymorphic profiles (97 polymorphic markers out of a total of 101 markers) suggests the existence of very high levels of genetic variation in the Indian population despite geographical isolation and opens out a strong possibility of further genetic improvement for superior artemisinin content. UPGMA analyses of RAPD and phytochemical trait data indicate that the wide phytochemical diversity is included within the genetic diversity. These results further support the prospects for selection and breeding of superior artemisinin containing lines.
Denitration of peroxynitrite‐treated proteins by “protein nitratases” from dog prostate
Authors: Kuo W. N. , Kanadia R. N. , Shanbhag V. R. 
Published: July 2007

AbstractPutative “protein nitratases,” which catalyze denitration of peroxynitrite (PN)‐treated proteins, were detected in the crude extract of dog prostate. Nitratase activity was monitored by the decreased intensity of nitrotyrosine immunoreactive‐bands in Western blot and increased nitrate level in dialysate of incubation mixture, which contained prostate crude extract, protease inhibitors and a PN‐treated substrate, such as treated histone (III‐S), BSA, invertase, or polylysine. Nitratases were activated by preincubation with m‐calpain/Ca2+. Furthermore, after denitration, the activity of PN/DTT‐treated invertase decreased to the similar activity level of DTT‐treated invertase. At least two different types of nitratases may occur: type I, reductant‐dependent, and type II, reductant‐independent.