id stringlengths 4 8 | title stringlengths 1 642 | abstract stringlengths 50 17.9k |
|---|---|---|
9329081 | VL:VH domain rotations in engineered antibodies: crystal structures of the Fab fragments from two murine antitumor antibodies and their engineered human constructs. | The crystal structures of two pairs of Fab fragments have been determined. The pairs comprise both a murine and an engineered human form, each derived from the antitumor antibodies A5B7 and CTM01. Although antigen specificity is maintained within the pairs, antigen affinity varies. A comparison of the hypervariable loo... |
9329021 | Imaging supramolecular aggregates in bile models and human bile. | Investigation of cholesterol crystallization is essential for the understanding of gallstone formation. Previous work has revealed a variety of aggregates of different sizes and shapes prior to the appearance of "classical" plate-like cholesterol monohydrate crystals both in native biles and model systems. In this arti... |
9327750 | Dephosphorylation of endotoxin by alkaline phosphatase in vivo. | Natural substrates for alkaline phosphatase (AP) are at present not identified despite extensive investigations. Difficulties in imagining a possible physiological function involve its extremely high pH optimum for the usual exogenous substrates and its localization as an ecto-enzyme. As endotoxin is a substance that c... |
9327745 | Role of glycosaminoglycans in determining the helicity of paired helical filaments. | It is known from previous work that tau is the main component of paired helical filaments (PHFs) and that it can assemble in vitro into polymers resembling PHFs when high concentrations of protein are used. In the search for molecules that can facilitate tau polymerization, a component of neurofibrillary tangles, hepar... |
9327743 | Loss of type IV collagen alpha 5 and alpha 6 chains in human invasive prostate carcinomas. | Type IV collagen, a major component of basement membranes, is organized in a network responsible for the mechanical resistance of the basement membranes. It also plays a key role in epithelial cell adhesion to basement membranes. This study was designed to investigate the distribution of type IV collagen alpha-chains i... |
9327732 | Dedifferentiation of atrial cardiomyocytes as a result of chronic atrial fibrillation. | Chronic atrial fibrillation was induced in goats by electrical pacing. After 9 to 23 weeks of sustained atrial fibrillation, the morphology of the atrial structures was examined. The majority of the cardiomyocytes exhibited marked changes in their cellular substructures, with the replacement of sarcomeres by glycogen a... |
9327541 | Purification and characterization of phenylacetaldehyde reductase from a styrene-assimilating Corynebacterium strain, ST-10. | A novel phenylacetaldehyde reductase was purified about 50-fold to homogeneity from Corynebacterium sp. strain ST-10, which can assimilate gaseous styrene as the sole carbon and energy source. The enzyme was inductively synthesized when grown on gaseous styrene and had an important role in styrene metabolism in vivo. T... |
9321670 | A fiber optic biosensor for fluorimetric detection of triple-helical DNA. | A fiber optic biosensor was used for the fluorimetric detection of T/AT triple-helical DNA formation. The surfaces of two sets of fused silica optical fibers were functionalized with hexaethylene oxide linkers from which decaadenylic acid oligonucleotides were grown in the 3'to 5'and 5'to 3'direction, respectively, usi... |
9321660 | Minor groove binding of a bis-quaternary ammonium compound: the crystal structure of SN 7167 bound to d(CGCGAATTCGCG)2. | The X-ray crystal structure of the complex between the synthetic antitumour and antiviral DNA binding ligand SN 7167 and the DNA oligonucleotide d(CGCGAATTCGCG)2 has been determined to an R factor of 18.3% at 2.6 A resolution. The ligand is located within the minor groove and covers almost 6 bp with the 1-methylpyridin... |
9321652 | Isoalloxazine derivatives promote photocleavage of natural RNAs at G.U base pairs embedded within helices. | We have recently shown that isoalloxazine derivatives are able to photocleave RNA specifically at G.U base pairs embedded within a helical stack. The reaction involves the selective molecular recognition of G.U base pairs by the isoalloxazine ring and the removal of one nucleoside downstream of the uracil residue. Diva... |
9321647 | Vaccinia virion protein VP8, the 25 kDa product of the L4R gene, binds single-stranded DNA and RNA with similar affinity. | Vaccinia virus protein VP8 is a 25 kDa product of the L4R gene and is an abundant virion protein that binds single-stranded (ss) and double-stranded (ds) DNA. Binding of ssDNA is preferred at high salt concentrations. Using a recombinant 25 kDa L4R (rL4R) protein and a gel mobility shift assay with radiolabelled oligon... |
9359406 | Phosphorylation of erythropoietin receptors in the endoplasmic reticulum by pervanadate-mediated inhibition of tyrosine phosphatases. | Erythropoietin (EPO) is the major hormone regulating the proliferation of erythroid precursors and their differentiation into erythrocytes. Ligand binding to the erythropoietin receptor (EPO-R), a member of the cytokine receptor family, triggers Tyr phosphorylation of the surface form of the receptor, presumably mediat... |
9359397 | Mechanism and regulation of Mg-chelatase. | Mg-chelatase catalyses the insertion of Mg into protoporphyrin IX (Proto). This seemingly simple reaction also is potentially one of the most interesting and crucial steps in the (bacterio)chlorophyll (Bchl/Chl)-synthesis pathway, owing to its position at the branch-point between haem and Bchl/Chl synthesis. Up until t... |
9324328 | A multinuclear MR study of Gd-EOB-DTPA: comprehensive preclinical characterization of an organ specific MRI contrast agent. | The characterization of the hepatobiliary contrast agent Gd-EOB-DTPA (gadolinium 3, 6, 9-triaza-3, 6, 9-tris(carboxymethyl)-4-(4-ethoxybenzyl)-undecandicarboxylic acid) in various media (water solution, protein containing solution, phosphorylated metabolites solution, and excised and perfused liver) was performed using... |
9324254 | Structure-function analyses of the Ssc1p, Mdj1p, and Mge1p Saccharomyces cerevisiae mitochondrial proteins in Escherichia coli. | The DnaK, DnaJ, and GrpE proteins of Escherichia coli have been universally conserved across the biological kingdoms and work together to constitute a highly efficient molecular chaperone machine. We have examined the extent of functional conservation of Saccharomyces cerevisiae Ssc1p, Mdj1p, and Mge1p by analyzing the... |
9322439 | Chiral discrimination of inhalation anesthetics and methyl propionates by thickness shear mode resonators: new insights into the mechanisms of enantioselectivity by cyclodextrins. | The discrimination of the enantiomers of methyl lactate, methyl 2-chloropropionate, and the inhalation anesthetics enflurane, isoflurane, and desflurane in the gas phase has been performed using thickness shear mode resonators. The selective coating was a modified perpentylated gamma-cyclodextrin derivative dissolved i... |
9312103 | Efficient mammalian protein synthesis requires an intact F-actin system. | The mammalian protein synthesizing system is highly organized in vivo, and its substrate, tRNA, is channeled throughout the translation process. However, the cellular components responsible for this organization are not known. To examine this question a series of studies was carried out using intact and permeabilized C... |
9312049 | Transcriptional silencing by the mycobacteriophage L5 repressor. | The success of a temperate bacteriophage is dependent upon its ability to completely shut down expression of its lytic genes during lysogenic growth. Mycobacteriophage L5 accomplishes this by an atypical phage repressor, gp71, which binds to multiple asymmetric DNA sites. L5 gp71 regulates transcription initiation at a... |
9315633 | IRF-7, a new interferon regulatory factor associated with Epstein-Barr virus latency. | The Epstein-Barr virus (EBV) BamHI Q promoter (Qp) is the only promoter used for the transcription of Epstein-Barr virus nuclear antigen 1 (EBNA-1) mRNA in cells in the most restricted (type I) latent infection state. However, Qp is inactive in type III latency. With the use of the yeast one-hybrid system, a new cellul... |
9315631 | Multicopy suppressors of phenotypes resulting from the absence of yeast VDAC encode a VDAC-like protein. | The permeability of the outer mitochondrial membrane to most metabolites is believed to be based in an outer membrane, channel-forming protein known as VDAC (voltage-dependent anion channel). Although multiple isoforms of VDAC have been identified in multicellular organisms, the yeast Saccharomyces cerevisiae has been ... |
9311906 | Biochemical characterization of a smaller form of recombinant Norwalk virus capsids assembled in insect cells. | The expression of the single capsid protein of Norwalk virus (NV) in Spodoptera frugiperda (Sf9) insect cells infected with recombinant baculovirus results in the assembly of virus-like particles (VLPs) of two sizes, the predominant 38-nm, or virion-size VLPs, and smaller, 23-nm VLPs. Here we describe the purification ... |
9311900 | Competitive binding of viral E2 protein and mammalian core-binding factor to transcriptional control sequences of human papillomavirus type 8 and bovine papillomavirus type 1. | The promoter P7535 of human papillomavirus type 8 and the promoter P7185 of bovine papillomavirus type 1 are negatively regulated by viral E2 proteins via the promoter proximal binding sites P2 and BS1, respectively. Mutations of these E2 binding sites can reduce basal promoter activity. This suggests binding of a tran... |
9311852 | Pseudorabies virus glycoprotein L is necessary for virus infectivity but dispensable for virion localization of glycoprotein H. | Herpesviruses contain a number of envelope glycoproteins which play important roles in the interaction between virions and target cells. Although several glycoproteins are not present in all herpesviruses, others, including glycoproteins H and L (gH and gL), are conserved throughout the Herpesviridae. To elucidate comm... |
9311835 | trans-Dominant and non-trans-dominant mutant simian virus 40 large T antigens show distinct responses to ATP. | Simian virus 40 (SV40) DNA replication requires the coordinated action of multiple biochemical activities intrinsic to the virus-encoded large tumor antigen (T antigen). We report the preliminary biochemical characterization of the T antigens encoded by three SV40 mutants, 5030, 5031, and 5061, each of which have alter... |
9311825 | Characterization of engineered hepatitis C virus NS3 protease inhibitors affinity selected from human pancreatic secretory trypsin inhibitor and minibody repertoires. | Given the extent of hepatitis C virus (HCV) infection as a worldwide health problem and the lack of effective treatment, the development of anti-HCV drugs is an important and pressing objective. Previous studies have indicated that proteolytic events mediated by the NS3 protease of HCV are fundamental to the generation... |
9311821 | Hierarchy of Epstein-Barr virus-specific cytotoxic T-cell responses in individuals carrying different subtypes of an HLA allele: implications for epitope-based antiviral vaccines. | Major histocompatibility complex class I-restricted Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) in healthy virus carriers constitute a primary effector arm of the immune system in controlling the proliferation of virus-infected B cells in vivo. These CTLs generally recognize target epitopes include... |
9311800 | The N-terminal region of the luteovirus readthrough domain determines virus binding to Buchnera GroEL and is essential for virus persistence in the aphid. | Luteoviruses and the luteovirus-like pea enation mosaic virus (PEMV; genus Enamovirus) are transmitted by aphids in a circulative, nonreplicative manner. Acquired virus particles persist for several weeks in the aphid hemolymph, in which a GroEL homolog, produced by the primary endosymbiont of the aphid, is abundantly ... |
9311793 | Expression and self-assembly of empty virus-like particles of hepatitis E virus. | Hepatitis E virus (HEV) is a pathogenic agent that causes fecally-orally transmitted acute hepatitis. The genome, a single-stranded positive-sense RNA, encodes three forward open reading frames (ORFs), in which an approximately 2-kb structural protein is located in the 3' end. To produce HEV-like particles the structur... |
9355727 | Syndecans: multifunctional cell-surface co-receptors. | This review will summarize our current state of knowledge of the structure, biochemical properties and functions of syndecans, a family of transmembrane heparan sulphate proteoglycans. Syndecans bind a variety of extracellular ligands via their covalently attached heparan sulphate chains. Syndecans have been proposed t... |
9297704 | Microsatellites of the parasitic nematode Haemonchus contortus: polymorphism and linkage with a direct repeat. | To develop tools to analyse parasitic nematode population structures and the effects of selection pressure on the nematode population, we isolated and characterised 13 microsatellite markers of the nematode Haemonchus contortus. The density of CA/GT microsatellites, once in 575 kb, is lower than in mammals. Although th... |
10851481 | A CDR-grafted (humanized) domain-deleted antitumor antibody. | While several murine monoclonal antibodies (MAbs) directed against carcinoma associated antigens have shown excellent tumor targeting properties in clinical trials, the use of radiolabeled MAbs for both diagnostic and therapeutic applications has been hindered by two factors: (a) the induction of host anti-immunoglobul... |
9561721 | Supramolecular organization of the subsarcolemmal cytoskeleton of adult skeletal muscle fibers. A review. | This review is focused on the composition and organization of the junctional subsarcolemmal cytoskeleton of adult muscle fibers. The cytoskeleton of muscle fibers is organized in functionally distinct compartments and the subsarcolemmal cytoskeleton itself can be broadly divided into junctional (myotendinous junction, ... |
22358768 | Recombinant Human Albumin in Cell Culture: Evaluation of Growth-Promoting Potential for NRK and SCC-9 Cells In Vitro. | Serum-derived albumin has for a long time been used in cell culture media, but the exact role of albumin and/or impurities bound to albumin has not been precisely defined. In this study, recombinant human albumin was evaluated for its growth-promoting activity on two cell lines, NRK and SCC-9. For NRK cells, the recomb... |
21639283 | Cation selectivity of natural and synthetic ionophores probed with laser-induced liquid beam mass spectrometry. | The novel laser desorption method laser-induced liquid beam ionization/desorption (LILBID) is applied to the mass spectrometric examination of selective ion binding by natural and synthetic ionophores in methanol solutions. The ions are desorbed from a liquid jet with an IR laser pulse and then extracted perpendicularl... |
21639272 | Solvatochromic Study of Poly(vinyl chloride) Plasticizers and Their Solutions in Chloroform: Application to Phenobarbital Partitioning and Molecular Recognition of Phenobarbital. | The possibility now exists, with the availability of several families of artificial molecular receptors, to create selective extraction media. More selective extractions will lead to cleaner chromatograms, with lower detection limits and perhaps higher accuracy for trace organic analysis by chromatography. Furthermore,... |
9299095 | Molecular Mechanics Study of the Inclusion Complexes of 2-Methyl Naphthoate with alpha- and beta-Cyclodextrins | Molecular mechanics calculations were employed to study the inclusion of 2-methyl naphthoate in alpha- and beta-cyclodextrin in vacuo and in the presence of water as a solvent. The driving forces for complexation are dominated by nonbonded van der Waals host:guest interactions in both environments. The 2-methyl naphtho... |
9299083 | The Effect of Ternary Complex Formation on the Partitioning of Pyrene and Anthracene in Aqueous Solutions Containing Sodium Dodecyl Sulfate and M-gamma-cyclodextrin | The partitioning behavior of pyrene and anthracene between n-decane and aqueous solutions containing a partially methylated gamma-cyclodextrin (M-gamma-CD) and sodium dodecyl sulfate (SDS) was studied by extraction experiments. At concentrations below the aqueous solubility of pyrene and anthracene both were found to f... |
11670125 | A Trapped Intermediate in the Copper(II)-Mediated Template Synthesis of an Amino Acid-Containing Ligand. | A transition metal ion-templating reaction that has been widely exploited for the synthesis of nitrogen macrocycles, sepulchrates, and linear tetradentate ligands is the template-directed Mannich condensation of carbon acid and aldehyde equivalents with amines. In the course of investigating the copper(II) template-dir... |
11670121 | Compound I and Compound II Analogues from Porpholactones. | The tetraaza macrocycles 2-oxa-3-oxotetramesitylporphine (|H(2) 1|) and 2-oxa-3-oxotetrakis(2,6-dichlorophenyl)porphine (|H(2) 2|) and the corresponding iron complexes (|Fe(III)(X) 1| and |Fe(III)(X) 2|; X= Cl(-), OH(-), or SO(3)CF(3)(-)) have been synthesized. These macrocycles are derived from porphyrins by transform... |
11670120 | Cyclic Metalloporphyrin Trimers: (1)H NMR Identification of Trimeric Heterometallic (Iron(III), Gallium(III), Manganese(III)) 2-Hydroxy-5,10,15,20-tetraphenylporphyrins and X-ray Crystal Structure of the Iron(III) 2-Hydroxy-5,10,15,20-tetra-p-tolylporphyrin Trimer(1). | Oligomerization of a mixture of monomeric iron(III) 2-hydroxy-5,10,15,20-tetraphenylporphyrin, (2-OH-TPP)Fe(III)Cl, manganese(III) 2-hydroxy-5,10,15,20-tetraphenylporphyrin, (2-OH-TPP)Mn(III)Cl, and gallium(III) 2-hydroxy-5,10,15,20-tetraphenylporphyrin, (2-OH-TPP)Ga(III)Cl, complexes affords the series of heterometall... |
11670118 | A New Class of Supramolecular, Mixed-Metal DNA-Binding Agents: The Interaction of Ru(II),Pt(II) and Os(II),Pt(II) Bimetallic Complexes with DNA. | A new type of mixed-metal, supramolecular complex has been designed that incorporates a platinum center to allow binding to DNA. The interaction of two such platinum heterobimetallic complexes of the general formula [(bpy)(2)M(dpb)PtCl(2)]Cl(2) (M = Ru(II), Os(II); bpy = 2,2'-bipyridine; dpb = 2,3-bis(2-pyridyl)benzoqu... |
15739483 | [Separation of drugs cephalexin, ampicillin, and their biosynthetic precursors L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val by capillary zone electrophoresis]. | The separation of drugs cephalexin, ampicillin and their biosynthetic precursors L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val was investigated by using capillary zone electrophoresis in acidic Tris-H3PO4 buffer at pH 2.3. With 50 mmol/L Tris-H3PO4 (pH 2.3) buffer, L-Phe-L-Cys-D-Val and D-Phe-L-Cys-D-Val were only partially ... |
15348705 | Synthesis and properties of poly(ethylene glycol) macromer/beta-chitosan hydrogels. | Semi-interpenetrating polymer network (semi-IPN) hydrogels composed of beta-chitosan and poly(ethylene glycol) diacrylate macromer (PEGM) were synthesized and characterized for the application as potential biomedical materials. The mixture of PEGM and beta-chitosan, dissolved in water including a small amount of acetic... |
9480020 | [The theory and practice of the creation of antisignature oligodeoxyribonucleotides as universal antimicrobial agents (the principles of a drug technology of the 21st century)]. | Gene-directed and anti-sense (mRNA-directed) synthetic oligonucleotides (SO) have a common main shortcoming. That is the necessity to introduce intercalators to their composition for the stronger interaction with targets to prevent their separation from the latter by DNA-polymerase and RNA-polymerase complexes which wo... |
9400716 | Alterations in protein glycosylation in PMA-differentiated U-937 cells exposed to mineral particles. | Carbohydrate moieties of cell glycoconjugates play a pivotal role in molecular recognition phenomena involved in the regulation of most biological systems and the changes observed in cell surface carbohydrates during cell activation or differentiation frequently modulate certain cell functions. Consequently, some aspec... |
9372279 | Micellar electrokinetic capillary chromatography (MECC) of UV-absorbing constituents in normal urine: a chemometric optimisation of the separation. | A micellar electrokinetic capillary chromatography (MECC) method when compared to free solution capillary electrophoresis (CZE) was shown to offer improved selectivity and resolution for the separation of UV-absorbing components of human urine. Some of the factors affecting MECC separation e.g. methanol concentration, ... |
9368668 | Molecular mechanisms of thrombin function. | The discovery of thrombin as a Na(+)-dependent allosteric enzyme has revealed a novel strategy for regulating protease activity and specificity. The alllosteric nature of this enzyme influences all its physiologically important interactions and rationalizes a large body of structural and functional information. For the... |
9368383 | Enantiomer separation of acidic racemates by capillary electrophoresis using cationic and amphoteric beta-cyclodextrins as chiral selectors. | Enantiomer separations of various acidic racemates were performed by capillary electrophoresis (CE) using a commercial cationic beta-cyclodextrin (beta-CD), quaternary ammonium beta-CD (QA-beta-CD), and a commercial amphoteric beta-CD (AM-beta-CD) as chiral selectors. Eleven acidic racemates were successfully separated... |
9364471 | Pharmacological characterization of novel A3 adenosine receptor-selective antagonists. | The effects of putative A3 adenosine receptor antagonists of three diverse chemical classes (the flavonoid MRS 1067, the 6-phenyl-1,4-dihydropyridines MRS 1097 and MRS 1191, and the triazoloquinazoline MRS 1220) were characterized in receptor binding and functional assays. MRS1067, MRS 1191 and MRS 1220 were found to b... |
9364944 | Extreme axial equalization and wide distribution of recombination nodules in the primitive ZW pair of Rhea americana (Aves, Ratitae). | Pachytene oocytes from the ratite bird Rhea americana were used for synaptonemal complex analysis with a surface spreading technique and phosphotungstic acid staining. The ZW bivalent is slightly smaller than the fourth autosomal bivalent and clearly shows unequal W and Z axes only in 27% of the bivalents. Most of the ... |
9364943 | Male-biased distribution of the human Y chromosomal genes SRY and ZFY in the lizard Calotes versicolor, which lacks sex chromosomes and temperature-dependent sex determination. | In the present investigation on the lizard Calotes versicolor, which lacks temperature-dependent sex determination, all the conventional cytological techniques used failed to resolve a distinguishable pair of sex chromosomes. However, probing of the genome with the human Y-linked genes SRY and ZFY showed sex-specific b... |
9364942 | High heterochromatin content in somatic chromosomes of two unrelated species of Diplopoda (Myriapoda). | For the first time, a conventional analysis of C-banded karyotypes was carried out in two distantly related diplopod species; this revealed an impressive percentage of heterochromatin in both genomes. In Acanthopetalum sicanum (Order Callipodida) (2n = 12), heterochromatin constitutes about 60% of the total DNA in fema... |
9364941 | The distribution of binding sites for centromere protein B (CENP-B) is partly conserved among diverged higher order repeating units of human chromosome 6-specific alphoid DNA. | We previously reported the isolation of alphoid satellite clones from a human genomic library using a DNA immunoprecipitation with centromere protein B (CENP-B). Here, we have characterized the distribution of CENP-B-binding sites on the 3-kb BamHI repeats of the cos2 clone. Using in situ hybridization, this alphoid sa... |
9364940 | Cell cycle changes in A-type lamin associations detected in human dermal fibroblasts using monoclonal antibodies. | A new panel of anti-A-type lamin monoclonal antibodies was generated. Epitope mapping was performed by immunoblotting against GST-lamin fusion peptides. Epitopes were mapped to four different regions of human lamin A and three different regions of human lamin C. The distribution of A-type lamins was compared with the d... |
9364939 | Physical relationship between satellite I and II DNA in centromeric regions of sheep chromosomes. | Fluorescence in situ hybridization (FISH) with probes representing sheep satellite I and satellite II DNAs shows a different distribution of the two repetitive DNA families in the centromeric region of most chromosomes. The single signal per chromosome produced by the satellite I probe suggests close proximity of this ... |
9364938 | The STR120 satellite DNA of soybean: organization, evolution and chromosomal specificity. | A highly repeated DNA sequence family, STR120, with tandemly arranged repetitive units (monomers) of approximately 120bp, has been identified in soybean [Glycine max (L.) Merr.]. Five related clones showing tandem repeats of a 120-bp-long monomer were isolated from a soybean genomic library. Results of Southern blottin... |
9364937 | Specific induction of the hsr omega locus of Drosophila melanogaster by amides. | We report here that 3-aminobenzamide and other amides, such as formamide, acetamide and nicotinamide, specifically induce a high rate of transcription at the 93D puff (the hsr omega heat shock gene) in polytene chromosomes of Drosophila melanogaster. Other chemicals, such as benzamide, colchicine, thiamphenicol and par... |
9380685 | B cell receptor-associated protein alpha4 displays rapamycin-sensitive binding directly to the catalytic subunit of protein phosphatase 2A. | Recently, TAP42 was isolated as a high copy suppressor of sit4-, a yeast phosphatase related to protein phosphatase 2A (PP2A). TAP42 is related to the murine alpha4 protein, which was discovered independently by its association with Ig-alpha in the B cell receptor complex. Herein we show that a glutathione S-transferas... |
9379451 | Conformational studies of paclitaxel analogs modified at the C-2' position in hydrophobic and hydrophilic solvent systems. | The conformations of two paclitaxel analogs modified at the C-2' position, 2'-deoxypaclitaxel and 2'-methoxypaclitaxel, were studied in hydrophobic and hydrophilic solvent systems by a combination of NMR spectroscopy, CD measurements, and molecular modeling. Both analogs have hydrophobic and hydrophilic conformations t... |
9376718 | Chiral resolution of flobufen by high performance liquid chromatography and capillary electrophoresis. | The enantiomeric separation of an anti-inflammatory drug flobufen was performed on various chiral columns in liquid chromatography and by reversed phase chromatography and by capillary electrophoresis with beta-cyclodextrin as a chiral selector in the mobile phase and background electrolyte, respectively. The elution o... |
9376706 | Direct enantiomeric separations by high performance liquid chromatography using cyclodextrins. | Due to their identical chemical and physical properties, the separation of enantiomers has been considered one of the most difficult challenges in chemistry from both an analytical or a preparative viewpoint. With the development and commercialization of many new or improved chiral stationary phases and chiral additive... |
9354242 | Effect of stereochemistry on the transport of Aca-linked beta-turn peptidomimetics across a human intestinal cell line. | Transcellular transport is one of the most important barriers facing the development of new therapeutic agents. However, little is known about the specific effects of structure and particularly stereochemistry on cell permeability. An attractive in vitro model has been developed for the direct assessment of cell transp... |
9424619 | [Macromolecular contrast media for MR mammography. A new approach to characterizing breast tumors]. | The value of macromolecular contrast agents (MMCM) for the characterization of benign and malignant breast tumors will be demonstrated in this review. Animal studies suggest a high potential of MMCM to increase the specificity of MR-mammography. The concept of tumor differentiation is based on the pathological hyperper... |
9417494 | [Selenium administration in patients with sepsis syndrome. A prospective randomized study]. | <h4>Patients and method</h4>In this study the effect of antioxidative therapy with sodium selenite was investigated in patients with systemic inflammatory response syndrome (S. I. R. S.) and multiple organ failure. 40 patients were included in this prospective randomized study. The patients were observed over a period ... |
9342658 | Guidelines in selecting ligand concentrations for the determination of binding constants by affinity capillary electrophoresis. | This study examined various factors that affect the selection of ligand concentrations when using affinity capillary electrophoresis (ACE) for the determination of equilibrium constants in free solution. Two groups of model systems were used in this work: the binding of nitrophenols to alpha- or beta-cyclodextrin and t... |
9342223 | Chloroplast SecA functions as a membrane-associated component of the Sec-like protein translocase of pea chloroplasts. | Protein cross-linking studies with a thylakoid membrane translocation intermediate were used to demonstrate that chloroplast SecA functions as a membrane-associated component of the Sec-like ATP-dependent protein translocase of pea chloroplasts. In assays with isolated thylakoids, it was observed that translocation of ... |
9331407 | Engineered intermodular and intramodular polyketide synthase fusions. | <h4>Background</h4>Modular polyketide synthases (PKSs) are very large multifunctional enzyme complexes that synthesize a number of medicinally important natural products. The modular arrangement of active sites has made these enzyme systems amenable to combinatorial manipulation for the biosynthesis of novel polyketide... |
9331403 | How corrinoids are synthesized without oxygen: nature's first pathway to vitamin B12. | <h4>Background</h4>During the biosynthesis of vitamin B12, the aerobic bacterium Pseudomonas denitrificans uses two enzymes, CobG and CobJ, to convert precorrin-3 to the ring-contracted intermediate, precorrin-4. CobG is a monooxygenase that adds a hydroxyl group, derived from molecular oxygen, to C-20, whereas CobJ is... |
9338969 | Coexpression of the maize delta-zein and beta-zein genes results in stable accumulation of delta-zein in endoplasmic reticulum-derived protein bodies formed by beta-zein. | Zeins, the major seed storage proteins of maize, are of four distinct types: alpha, beta, delta, and gamma. They are synthesized on the rough endoplasmic reticulum (ER) in a sequential manner and deposited in ER-derived protein bodies. We investigated the potential for producing sulfur-rich beta-zein and delta-zein pro... |
9337074 | Regulation of A1 adenosine receptors by amiodarone and electrical stimulation in rat myocardial cells in vitro. | The effects of conditions that either increase or decrease heart rate on the pharmacological properties of adenosine receptors in cultured rat myocytes were examined. Levels of A1 adenosine receptors, following prolonged treatment with electrical stimulation (ES) or the antiarrhythmic drug amiodarone, were determined u... |
9331907 | Intra-hippocampal estradiol infusion enhances memory in ovariectomized rats. | Ovariectomized adult Long-Evans rats received an eight-trial training session in a hippocampal-dependent hidden platform water maze task. Following trial 8, rats received an intra-hippocampal injection of estradiol in a water soluble cyclodextrin inclusion complex (1.0, 2.0 or 5.0 micrograms/0.5 microliter), or saline.... |
9327782 | Decreased reverse cholesterol transport from Tangier disease fibroblasts. Acceptor specificity and effect of brefeldin on lipid efflux. | Tangier disease is characterized by HDL hypercatabolism and increased deposition of cholesterol in tissues. Tangier disease skin fibroblasts have decreased apoA-I-mediated cholesterol and phospholipid efflux, which may lead to the excess accumulation of cellular cholesterol. The mechanism of apolipoprotein-mediated cho... |
9327136 | Synthesis and biological properties of mannosylated starburst poly(amidoamine) dendrimers. | Starburst PAMAM dendrimers ending with mannopyranoside residues were readily synthesized in large scale and good yields from commercially available dendrimers bearing high-density amine functionality on their surface and p-isothiocyanatophenyl 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranoside. The first four generations o... |
9322259 | Posttraining estradiol injections enhance memory in ovariectomized rats: cholinergic blockade and synergism. | The present experiments examined acute posttraining estrogenic influences on memory in ovariectomized rats. In experiment 1 rats received a single 8-trial (30-s ITI) training session with a submerged escape platform located in the same quadrant of a circular water maze on all trials. Following trial 8, rats received a ... |
9312034 | Structural basis of the RNA-binding specificity of human U1A protein. | The RNP domain is a very common eukaryotic protein domain involved in recognition of a wide range of RNA structures and sequences. Two structures of human U1A in complex with distinct RNA substrates have revealed important aspects of RNP-RNA recognition, but have also raised intriguing questions concerning the origin o... |
9312018 | Growth factor activation of MAP kinase requires cell adhesion. | The MAP kinase pathway is a major regulator of both normal and oncogenic growth. We report that activation of the MAP kinase ERK2 by serum or purified growth factors is strongly dependent on cell adhesion to extracellular matrix proteins. This effect is specific to soluble growth factors, since suspended cells still ac... |
9312009 | Interaction of influenza virus haemagglutinin with sphingolipid-cholesterol membrane domains via its transmembrane domain. | Sphingolipid-cholesterol rafts are microdomains in biological membranes with liquid-ordered phase properties which are implicated in membrane traffic and signalling events. We have used influenza virus haemagglutinin (HA) as a model protein to analyse the interaction of transmembrane proteins with these microdomains. H... |
9311985 | RF2a, a bZIP transcriptional activator of the phloem-specific rice tungro bacilliform virus promoter, functions in vascular development. | Rice tungro bacilliform virus (RTBV) replicates only in phloem cells in infected rice plants and its promoter drives strong phloem-specific reporter gene expression in transgenic rice plants. We isolated a cDNA encoding a basic leucine zipper (bZIP) protein, RF2a, which binds to the Box II cis element that is important... |
9311978 | Crystal structure of the site-specific recombinase, XerD. | The structure of the site-specific recombinase, XerD, that functions in circular chromosome separation, has been solved at 2.5 A resolution and reveals that the protein comprises two domains. The C-terminal domain contains two conserved sequence motifs that are located in similar positions in the structures of XerD, la... |
9311977 | Molecular recognition of human angiogenin by placental ribonuclease inhibitor--an X-ray crystallographic study at 2.0 A resolution. | Human placental RNase inhibitor (hRI), a leucine-rich repeat protein, binds the blood vessel-inducing protein human angiogenin (Ang) with extraordinary affinity (Ki <1 fM). Here we report a 2.0 A resolution crystal structure for the hRI-Ang complex that, together with extensive mutagenesis data from earlier studies, re... |
9311486 | Effects of N-acetylcysteine on tissue oxygenation in patients with multiple organ failure and evidence of tissue hypoxia. | Covert tissue hypoxia, particularly of the splanchnic region, appears important in the pathogenesis of multiple organ failure (MOF). This investigation evaluates the effects of N-acetylcysteine (NAC) upon several measures of tissue oxygenation in 10 patients with severe MOF and evidence of splanchnic hypoxia (as sugges... |
9307964 | Flight muscle function in Drosophila requires colocalization of glycolytic enzymes. | Structural relationships between the myofibrillar contractile apparatus and the enzymes that generate ATP for muscle contraction are not well understood. We explored whether glycolytic enzymes are localized in Drosophila flight muscle and whether localization is required for function. We find that glycerol-3-phosphate ... |
9305965 | Utilization of enzymatically phosphopantetheinylated acyl carrier proteins and acetyl-acyl carrier proteins by the actinorhodin polyketide synthase. | The functional reconstitution of two purified proteins of an aromatic polyketide synthase pathway, the acyl carrier protein (ACP) and holo-ACP synthase (ACPS), is described. Holo-ACPs were enzymatically synthesized from coenzyme A and apo-ACPs using Escherichia coli ACPS. Frenolicin and granaticin holo-ACPs formed in t... |
9306662 | Optimization of a simple method for the chiral separation of phenethylamines of forensic interest based on cyclodextrin complexation capillary electrophoresis and its preliminary application to the analysis of human urine and hair. | Because of the forensic importance of the chiral analysis of amphetamine and other phenethylamines for investigating their synthetic pathways and the metabolic patterns of these compounds, a capillary electrophoresis method has been developed based on the chiral selectivity of beta-cyclodextrin. The influence of differ... |
9303538 | SKN-1 domain folding and basic region monomer stabilization upon DNA binding. | The SKN-1 transcription factor specifies early embryonic cell fates in Caenorhabditis elegans. SKN-1 binds DNA at high affinity as a monomer, by means of a basic region like those of basic-leucine zipper (bZIP) proteins, which bind DNA only as dimers. We have investigated how the SKN-1 DNA-binding domain (the Skn domai... |
9303537 | An RNA enhancer in a phage transcriptional antitermination complex functions as a structural switch. | Antitermination protein N regulates the transcriptional program of phage lambda through recognition of RNA enhancer elements. Binding of an arginine-rich peptide to one face of an RNA hairpin organizes the other, which in turn binds to the host antitermination complex. The induced RNA structure mimics a GNRA hairpin, a... |
9303533 | Notochord induction of zebrafish slow muscle mediated by Sonic hedgehog. | The patterning of vertebrate somitic muscle is regulated by signals from neighboring tissues. We examined the generation of slow and fast muscle in zebrafish embryos and show that Sonic hedgehog (Shh) secreted from the notochord can induce slow muscle from medial cells of the somite. Slow muscle derives from medial ada... |
9303408 | Efficacy of nikkomycin Z against experimental pulmonary blastomycosis. | Nikkomycin Z is a chitin synthetase inhibitor. In vitro, nikkomycin Z had good activity against Blastomyces dermatitidis, with an MIC of 0.78 microg/ml and a minimal fungicidal concentration of 3.1 microg/ml. The efficacies of various treatment durations (3, 5, or 10 days) and doses (200, 400, or 1,000 mg/kg of body we... |
9303382 | Streptogramin B biosynthesis in Streptomyces pristinaespiralis and Streptomyces virginiae: molecular characterization of the last structural peptide synthetase gene. | Streptomyces pristinaespiralis and S. virginiae both produce closely related hexadepsipeptide antibiotics of the streptogramin B family. Pristinamycins I and virginiamycins S differ only in the fifth incorporated precursor, di(mono)methylated amine and phenylalanine, respectively. By using degenerate oligonucleotide pr... |
9299348 | Molecular recognition in signal transduction: the interaction surfaces of the Spo0F response regulator with its cognate phosphorelay proteins revealed by alanine scanning mutagenesis. | The phosphorelay, a signal transduction pathway composed of two-component regulatory proteins, mediates the initiation of sporulation in Bacillus subtilis. Environmental and physiological signals activate the autophosphorylation of histidine kinases, KinA and KinB, which transfer the phosphoryl group to Spo0F, a single... |
9300499 | Structural studies on membrane-embedded influenza hemagglutinin and its fragments. | The mechanism of influenza virus hemagglutinin (HA)-mediated membrane fusion has been inferred in part from studies examining pH-induced structural changes in soluble HA derivatives lacking the viral membrane anchor and, sometimes, the fusion peptide (the C- and N-terminal residues of the HA2 chain, respectively). To r... |
9300492 | Empirical parameterization of a model for predicting peptide helix/coil equilibrium populations. | A modification of the Lifson-Roig formulation of helix/coil transitions is presented; it (1) incorporates end-capping and coulombic (salt bridges, hydrogen bonding, and side-chain interactions with charged termini and the helix dipole) effects, (2) helix-stabilizing hydrophobic clustering, (3) allows for different inhe... |
9300481 | Crystal structures of bovine chymotrypsin and trypsin complexed to the inhibitor domain of Alzheimer's amyloid beta-protein precursor (APPI) and basic pancreatic trypsin inhibitor (BPTI): engineering of inhibitors with altered specificities. | The crystal structures of the inhibitor domain of Alzheimer's amyloid beta-protein precursor (APPI) complexed to bovine chymotrypsin (C-APPI) and trypsin (T-APPI) and basic pancreatic trypsin inhibitor (BPTI) bound to chymotrypsin (C-BPTI) have been solved and analyzed at 2.1 A, 1.8 A, and 2.6 A resolution, respectivel... |
9298959 | Structure-based discovery of ligands targeted to the RNA double helix. | Ligands capable of specific recognition of RNA structures are of interest in terms of the principles of molecular recognition as well as potential chemotherapeutic applications. We have approached the problem of identifying small molecules with binding specificity for the RNA double helix through application of the DOC... |
9294821 | Physicochemical characterization of different batches of ethylated beta-cyclodextrins. | Different ethylated beta-cyclodextrin (Et-beta-CD) derivatives were obtained by various synthetic routes and their chemical structures and physical properties were elucidated. The aqueous solubility studies were carried out at 25 and 37 degrees C. A gas phase chromatography analysis, with head space extraction, was dev... |
9294451 | Transcriptional regulation of the Enterococcus faecium BM4147 vancomycin resistance gene cluster by the VanS-VanR two-component regulatory system in Escherichia coli K-12. | An Escherichia coli K-12 model system was developed for studying the VanS-VanR two-component regulatory system required for high-level inducible vancomycin resistance in Enterococcus faecium BM4147. Our model system is based on the use of reporter strains with lacZ transcriptional and translational fusions to the PvanR... |
9294231 | Neuroprotective activity of a new class of steroidal inhibitors of the N-methyl-D-aspartate receptor. | Release of the excitatory neurotransmitter glutamate and the excessive stimulation of N-methyl-D-aspartate (NMDA)-type glutamate receptors is thought to be responsible for much of the neuronal death that occurs following focal hypoxia-ischemia in the central nervous system. Our laboratory has identified endogenous sulf... |
9294212 | Paracrine stimulation of interstitial collagenase (MMP-1) in the human endometrium by interleukin 1alpha and its dual block by ovarian steroids. | In the cycling human endometrium, the expression of interstitial collagenase (MMP-1) and of several related matrix metalloproteinases (MMPs) follows the late-secretory fall in sex steroid plasma concentrations and is thought to be a critical step leading to menstruation. The rapid and extensive lysis of interstitial ma... |
9294185 | The alpha chain of laminin-1 is independently secreted and drives secretion of its beta- and gamma-chain partners. | A mammalian recombinant strategy was established to dissect rules of basement membrane laminin assembly and secretion. The alpha-, beta-, and gamma-chain subunits of laminin-1 were expressed in all combinations, transiently and/or stably, in a near-null background. In the absence of its normal partners, the alpha chain... |
9294176 | Cloning and characterization of the mouse vitamin D receptor promoter. | The gene encoding the mouse vitamin D receptor has been cloned. A new exon 1 has been found that changes the numbering established for the human VDR gene. Exons 2 and 3 in the human VDR gene (coding for the zinc fingers 1 and 2, respectively) are named exons 3 and 4 in the mouse vitamin D receptor. The 1.5-kb 5'-flanki... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.