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7541225 | Specific hemoglobin (poly)saccharide recognition. | Hemoglobin (Hb) is not a glycoprotein but can easily be glycosylated by a non-enzymatic mechanism. Based on some kinetic particularities, consisting in a faster glycosylation of the amine terminal group of the beta-chain located on the allosteric site, a hypothesis of a recognition center for specific sugars has been a... |
7541224 | A novel class of embryonic cell adhesion glycan epitopes is expressed in human colon carcinomas. | A new class of acidic glycans isolated from marine sponges and sea urchin embryos was shown to mediate cell adhesion via carbohydrate-carbohydrate interactions. Cell aggregation blocking monoclonal antibodies (Block 1 and Block 2 mAbs) directed against these polysaccharides localized functional epitopes in embryonic se... |
7791550 | Preparation, physico-chemical characterization, and relaxometry studies of various gadolinium(III)-DTPA-bis(amide) derivatives as potential magnetic resonance contrast agents. | Macroscopic protonation constants were measured for a series of DTPA mono- and bis-amide ligands using potentiometric titrations. Proton NMR pH titrations yielded protonation populations of the various nitrogen and oxygen basic sites of the ligands for the different protonation stages. Amide formation decreased the bas... |
7788280 | Electron microscopic studies on intracellular phage development--history and perspectives. | This review is centered on the applications of thin sections to the study of intracellular precursors of bacteriophage heads. Results obtained with other preparation methods are included in so far as they are essential for the comprehension of the biological problems. This type of work was pioneered with phage T4, whic... |
7540055 | The importance of extended conformations and, in particular, the PII conformation for the molecular recognition of peptides. | Crystallographic, isotopic labeling nmr and transferred nuclear Overhauser effect studies have highlighted the extended conformation as a very important element of secondary structure at the binding site of many peptide/protein complexes including peptide inhibitors-enzymes, B-cell epitopes-antibodies, and T-cell epito... |
7775400 | Role of the C-terminal region of beta-amylase from barley. | To investigate the role of the C-terminal region of barley beta-amylase, plasmid delta 54 was constructed with an expression vector (pBETA92) of barley beta-amylase by site-directed mutagenesis. Escherichia coli JM109 harboring plasmid delta 54 was expected to express delta 54 beta-amylase in which 54 amino acid residu... |
7775011 | Unprotected peptides as building blocks for branched peptides and peptide dendrimers. | We describe two new site-specific ligation methods for preparing branched peptide dendrimers such as multiple antigen peptide (MAP). Both methods are based on the general approach of exploiting the specific reaction between a weak base and an aldehyde under acidic conditions so that unprotected peptides can be used as ... |
7773178 | Hydrogen bonding motifs of protein side chains: descriptions of binding of arginine and amide groups. | The modes of hydrogen bonding of arginine, asparagine, and glutamine side chains and of urea have been examined in small-molecule crystal structures in the Cambridge Structural Database and in crystal structures of protein-nucleic acid and protein-protein complexes. Analysis of the hydrogen bonding patterns of each by ... |
7773170 | Differentiation of peptide molecular recognition by phospholipase C gamma-1 Src homology-2 domain and a mutant Tyr phosphatase PTP1bC215S. | Activated epidermal growth factor receptor (EGFR) undergoes autophosphorylation on several cytoplasmic tyrosine residues, which may then associate with the src homology-2 (SH2) domains of effector proteins such as phospholipase C gamma-1 (PLC gamma-1). Specific phosphotyrosine (pTyr)-modified EGFR fragment peptides can... |
7768257 | Oral bioavailability of CHF1194, an inclusion complex of piroxicam and beta-cyclodextrin, in healthy subjects under single dose and steady-state conditions. | CHF1194 is an inclusion complex of beta-cyclodextrin with the nonsteroidal anti-inflammatory drug piroxicam. In man, beta-cyclodextrin acts as a carrier of piroxicam. As the inclusion complex of piroxicam-beta-cyclodextrin is wettable and more water soluble, the absorption rate of the drug is increased whilst its other... |
7762966 | Disseminated intravascular coagulation in transfusion-associated graft-versus-host disease. Report of two cases. | In two cases of transfusion-associated graft-versus-host disease (TA-GVHD), severe bleeding tendencies were observed besides the characteristic features of the disease. An elevation of fibrin degradation products (FDP), D-dimer, thrombin-antithrombin III complex (TAT) and plasmin-alpha 2 plasmin inhibitor complex (PIC)... |
7744487 | Severity of multiple organ failure (MOF) but not of sepsis correlates with irreversible platelet degranulation. | Multiple hemostatic changes occur in sepsis and multiple organ failure (MOF). To evaluate the role of platelets in patients with sepsis and MOF, we examined changes in surface glycoproteins on circulating platelets of 14 patients with suspected sepsis and MOF. The severity of sepsis and MOF was assessed by the Elebute ... |
7736665 | Regulation of beta-tubulin function and expression in Drosophila spermatogenesis. | In this study we examined two aspects of beta-tubulin function in Drosophila spermatogenesis: 1) beta-tubulin structural requirements for assembly of different categories of microtubules and 2) regulatory requirements for production of the correct tubulin protein level. In normal Drosophila spermatogenesis, the testis-... |
7735252 | Protective activity of hamamelitannin on cell damage induced by superoxide anion radicals in murine dermal fibroblasts. | Previously we demonstrated that hamamelitannin (2',5-di-O-galloyl hamamelose) in Hamamelis virginiana L. exhibits potent superoxide-anion scavenging activity. We then examined the physiological and pharmacological activities of hamamelitannin as well as its functional homologues, gallic acid and syringic acid. The foll... |
7734121 | Incorporation of sulphonated cyclodextrins into polypyrrole: an approach for the electro-controlled delivering of neutral drugs. | The electro-controlled delivery of drugs based on the doping-dedoping mechanism of Electro-Conducting Polymers is restricted to charged substances acting as dopants. In order to overcome this limitation, this study presents an approach where the trapping/delivering is based on host-guest interaction. As an example of a... |
7734117 | From neural chip and engineered biomolecules to bioelectronic devices: an overview. | At the first C.E.C. Workshop, in Brussels on 28-29 November 1991, attended by over 70 leading European scientists and industrialists, bioelectronics was defined as 'the use of biological materials and biological architectures for information processing systems and new devices'. At the end of the Frankfurt Workshop, bio... |
7728868 | Cytoskeletal domains in the activated platelet. | Platelets circulate in the blood as discoid cells which, when activated, change shape by polymerizing actin into various structures, such as filopodia and stress fibers. In order to understand this process, it is necessary to determine how many other proteins are involved. As a first step in defining the full complemen... |
7724491 | Differential effects of sulfate and sulfobutyl ether of beta-cyclodextrin on erythrocyte membranes in vitro. | The hemolytic activity of beta-cyclodextrin (beta-CyD) on rabbit erythrocytes was reduced by the introduction of negatively-charged groups onto the hydroxyls of beta-CyD; the membrane disrupting abilities decreased in the order of beta-CyD > 2-hydroxypropyl-beta-CyD (HP-beta-CyD) > sulfobutyl-beta-CyD (SB-beta-CyD) >> ... |
21619327 | Structural ion selectivity of thia crown ether compounds with a bulky block subunit and their application as an ion-sensing component for an ion-selective electrode. | Several 14-membered thia crown ether ionophores having a bulky block subunit were synthesized, and their chemical structures and ion selectivities were examined in detail when these compounds were used as an ion-sensing component of an ion-selective electrode. The ionophores of both cyclic and noncyclic thia ethers exh... |
18966705 | Extraction and determination of crown ethers from water samples using a membrane disk and gas chromatography. | A method for rapid extraction and determination of some crown ethers in aqueous matrices using octadecyl-bonded silica membrane disks and gas chromatography is presented. Extraction efficiency and the influence of vacuum pressure. pH, and type and least amount of eluting solvent used to extract the crown ethers from th... |
11667880 | Penicillin Acylase-Mediated Synthesis of 2-Acetyl-1-pyrroline and of 2-Propionyl-1-pyrroline, Key Roast-Smelling Odorants in Food. Inclusion Complexes with beta-Cyclodextrin and Their NMR and MS Characterization. | The synthesis of the strong natural roast odorants 1 and 2 is achieved from the C-6 isomeric alcohols 16 and 21 via the acetylenic C-6 and C-7 amines 8 and 9. Key step in the process is the hydrolysis of the N-phenylacetamides 12 and 13 by means of immobilized penicillin acylase, which affords the 1-amino-4,5-diketones... |
11667876 | Self-Inclusion Complexes Derived from Cyclodextrins: Synthesis and Characterization of 6(A),6(B)-Bis-O-[p-(allyloxy)phenyl]-Substituted beta-Cyclodextrins. | The syntheses, structures, and spectroscopic properties of 6(A),6(B)-bis-O-[p-(allyloxy)phenyl]-substituted beta-cyclodextrins have been investigated. Selective activation of the 6(A),6(B)-hydroxy groups was carried out by treating heptakis(2,3-di-O-methyl)-beta-cyclodextrin (1) with 2,4-dimethoxybenzene-1,5-disulfonyl... |
11667871 | Synthesis, Conformational Studies, X-ray Structures, and Complexation Properties of Semirigid Macrocyclic Phosphonamides. | The semirigid phosphonamide ligands 1-5 have been synthesized from the macrocyclic precursors 6-9 by reaction with 1,3-propanediol ditosylate or 1,2-dichloroethane. For the thiophosphoryl compounds 1 and 2, and the phosphoryl derivative 5, the reactions were carried out in biphasic aqueous NaOH solutions. The phosphory... |
11667859 | Solid and Solution Phase Organic Syntheses of Oligomeric Thioureas. | In order to study supramolecular architectures built from unnatural oligomeric and polymeric structures, one must first have an efficient synthetic strategy to produce them. Oligomers built from thiourea groups should form complex secondary and tertiary structures due to the hydrogen-bonding capabilities of the thioure... |
11666914 | Host-Guest Interactions of Inorganic Phosphates with the Copper(II) Complexes of the Hexaaza Macrocyclic Ligand 3,6,9,17,20,23-Hexaazatricyclo[23.3.1.1(11,15)]triaconta-1(29),11(30),12,14,25,27-hexaene. | The host-guest interactions between ortho-, pyro-, and tripolyphosphate anions and the mono and dinuclear copper(II) complexes of the hexaaza macrocyclic ligand BMXD (3,6,9,17,20,23-hexaazatricyclo[23.3.1.1(11,15)]triaconta-1(29),11(30),12,14,25,27-hexaene) were investigated by potentiometric equilibrium methods. Terna... |
11666912 | Synthesis and Properties of 5-Chloro-8-hydroxyquinoline-Substituted Azacrown Ethers: A New Family of Highly Metal Ion-Selective Lariat Ethers. | New 5-chloro-8-hydroxyquinoline (CHQ)-substituted aza-18-crown-6 (4), diaza-18-crown-6 (1), diaza-21-crown-7 (2), and diaza-24-crown-8 (3) ligands, where CHQ was attached through the 7-position, and aza-18-crown-6 (11) and diaza-18-crown-6 (10) macrocycles, where CHQ was attached through the 2-position, were prepared. ... |
11666908 | Complexation of Thorium(IV) and Uranium(IV) by a Hexaacetic Hexaaza Macrocycle: Kinetic and Thermodynamic Topomers of Actinide Chelates with a Large Cavity Ligand. | The solution behavior of the Th(IV) chelate with a polyaza polycarboxylic ligand, HEHA (1,4,7,10,13,16-hexaazacyclooctadecane-N,N ',N ",N "',N "",N ""'-hexaacetic acid), is investigated by one- and two-dimensional NMR spectroscopy. [Th(HEHA)](2)(-) exhibits a very unusual irreversible topomerization process from a kine... |
9100358 | An improved enzymatic assay for glucose determination in blood serum using a 1,1'-dimethylferricinium dye. | 1,1'-dimethylferricinium (DMFe+), a stable and pH-insensitive blue dye, was prepared via enzymatic oxidation of a 1,1'dimethyl-ferrocene (DMFe):2-hydroxypropyl-beta-cyclodextrin (HPCD) water-soluble inclusion complex, using bilirubin oxidase immobilized onto porous aminopropyl glass beads via glutaraldehyde activation.... |
9157366 | [Neuro-immuno-cutaneous system (NICS)]. | The concept of neuro-immuno-cutaneous system (NICS) means narrow interrelations between nervous system, immunity and skin. Indeed, there are numerous cellular contacts between nerve fibers, cutaneous cells and immune cells; cutaneous cells can synthesize neuromediators and they express receptors to these molecules; neu... |
9068375 | A study of growth factor receptors in human lens epithelial cells and their relationship to fiber differentiation. | Recent studies have demonstrated that several growth factors enhance fiber differentiation in cultured human lens epithelial (HLE) cells in early passages. However, these effects gradually decrease in cells of later passages. The purpose of this investigation is to test the hypothesis that the decreasing effect of grow... |
9068369 | IGF enhancement of FGF-induced fibre differentiation and DNA synthesis in lens explants. | The aim of this study was to carry but an analysis of the effects of insulin-like growth factors (IGFs) on responses induced by FGF in lens epithelial explants. Central explants from postnatal rats were cultured with concentrations of FGF-2 known to stimulate fibre differentiation or cell proliferation, with and withou... |
9038634 | The role of vaccines in the control of STDs: HPV vaccines. | Prophylactic vaccines for genital human papillomavirus (HPV) infection have been shown to be feasible in animal models, and suitable vaccine material based on virus-like particles can be produced in bulk at reasonable cost. Initiation of phase III clinical trials will follow definition of trial outcome measures through... |
9034780 | Characterization of the stereoselective metabolism of methadone and its primary metabolite via cyclodextrin capillary electrophoretic determination of their urinary enantiomers. | Using capillary zone electrophoresis with a phosphate buffer at pH 3, containing 4.3 mM hydroxypropyl-beta-cyclodextrin as chiral selector, the simultaneous separation of the enantiomers of methadone and its primary metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), is reported. After solid-phase ext... |
9034776 | A practical procedure for the determination of association constants of the analyte-chiral selector equilibria by capillary zone electrophoresis. | A practical procedure is proposed for the determination of association constants and mobility of the associate of a solute with a chiral selector in chiral separations by capillary zone electrophoresis. The procedure is based on the measurement of the effective mobility of a solute at zero and two different nonzero con... |
9032785 | [Prevention and treatment of postoperative septic MOF and DIC and efficacy of blood purification]. | Pathophysiologic concept of SIRS has been proposed for the better management of postoperative severe infection and septic MOF, and the concept has been found to be very useful. It is very important to identify the high risk SIRS patients of the development of septic MOF and to treat those patients aggressively to preve... |
9027848 | Merosin/laminin-2 and muscular dystrophy. | The laminins are a family of structural basement membrane components with major influences on cells. They are high molecular weight glycoproteins composed of three different but homologous chains, alpha, beta and gamma. At present 10 different chains have been identified. Each chain has a distinct structural organizati... |
9024978 | Chromosomes of Damaliscus (Artiodactyla, Bovidae): simple and complex centric fusion rearrangements. | G- and C-banded karyotypes of Damaliscus hunteri, D. lunatus and D. pygargus were compared using the standard karyotype of Bos taurus. Chromosomal complements were 2n = 36 in D. lunatus jimela, 2n = 38 in D. pygargus phillipsi and D. p. pygargus, and 2n = 44 in D. hunteri. The fundamental number in all karyotypes was 6... |
9024977 | Paternally inherited chromosomal structural aberrations detected in mouse first-cleavage zygote metaphases by multicolour fluorescence in situ hybridization painting. | We describe a fluorescence in situ hybridization (FISH) procedure for assessing zygotic risk of paternal exposure to endogenous or exogenous agents. The procedure employs multicolour FISH with chromosome-specific DNA painting probes plus DAPI staining for detecting both balanced and unbalanced chromosomal aberrations i... |
9024976 | Transcription of lampbrush chromosomes of a centromerically localized highly repeated DNA in pigeon (Columba) relates to sequence arrangement. | A highly repetitive, centromerically localized DNA sequence (PR1) has been isolated from the genomic DNA of two species of pigeon (Columba livia and C. palumbus). PR1 is approximately 900 bp long. It includes a sequence that is similar to the CENP-B box of mammals. It represents about 5% of the genome in C. livia and 2... |
9024975 | Characterization of the translocated chromosome using fluorescence in situ hybridization and random amplified polymorphic DNA on two Triticum aestivum-Thinopyrum intermedium translocation lines resistant to wheat streak mosaic or barley yellow dwarf virus. | Fluorescence in situ hybridization (FISH) was used to determine the breakpoint of the translocation chromosome in two bread wheat (Triticum aestivum) germplasm lines with Thinopyrum intermedium chromatin carrying resistance to either wheat streak mosaic virus (WSMV) or barley yellow dwarf virus (BYDV). In addition, gen... |
9024974 | Scanning ion analytical microscopy for high-resolution detection of 5-bromo-2'-deoxyuridine incorporation in metaphase chromosomes. | We investigated the possibilities of using scanning ion analytical microscopy (SIAM) to detect bromine in human metaphase chromosomes. The experiments were performed after incorporation of the thymidine analogue, 5-bromo-2'-deoxyuridine (BrdU), into the DNA or by in situ hybridization of a BrdU-labelled probe for the s... |
9024973 | Combined immunocytogenetic and molecular cytogenetic analysis of meiosis I human spermatocytes. | We have used a combination of immunocytogenetic and molecular cytogenetic technology on human spermatocytes to investigate (1) meiosis I chromosome pairing, and (2) organization of synaptonemal complex (SC)-associated chromatin with respect to whole chromosome paints, unique DNA sequences and repetitive DNA of heteroch... |
9024972 | Ribosomal RNA location in the Antarctic fish Champsocephalus gunnari (Notothenioidei, Channichthyidae) using banding and fluorescence in situ hybridization. | A biotinylated 28S rDNA probe was prepared from the genomic DNA of the Antarctic ice-fish Champsocephalus gunnari and hybridized to metaphase chromosomes of the same species by fluorescence in situ hybridization (FISH). The hybridization signal appeared over the whole heterochromatic arm of the submetacentric chromosom... |
9024828 | Heparan preserves intestinal perfusion after hemorrhage and resuscitation. | <h4>Background</h4>Multiple system organ failure (MOF) remains a major source of morbidity and mortality in trauma patients. Despite restoration of central hemodynamics, intestinal hypoperfusion can persist. Mucosal ischemia and barrier breakdown are factors in the genesis of MOF. Heparan sulfate is a gycosaminoglycan ... |
9022981 | Synthesis and biological evaluation of 2-amino-2-deoxy- and 6-amino-6-deoxy-cyclomaltoheptaose polysulfates as synergists for angiogenesis inhibition. | 2-Amino-2-deoxy-cyclomaltoheptaose was prepared from beta-cyclodextrin perbenzoate [heptakis(2,3,6-tri-O-benzoyl)cyclomaltoheptaose] by a series of reactions including selective de-O-benzoylation at C-2 of one of the perbenzoylated D-glucopyranosyl moieties, oxidation to the 2-ulose derivative, oxime formation, and red... |
9022689 | Photoaffinity labelling of a DNA-binding site on the globular domain of histone H5. | We have labelled a DNA-binding site on the globular domain of histone H5 (GH5) by ultraviolet-activated cross-linking of a self-complementary 5-bromodeoxyuridine (5BrU)-substituted oligonucleotide with the sequence 5'-AGCGA5BrUATCGCT-3'. Cross-linking was to His62, mainly to the protein backbone. This observation provi... |
9022308 | [Optic nerve regeneration by nerve transplantation]. | The optic nerve fibers of adult mammals, once injured, can not regenerate spontaneously. However, from recent studies it has become clear that when their extracellular environment is replaced with that of the peripheral nervous system, namely surrounded with Schwann cells, they can regenerate their axons through the gr... |
9017455 | Cyclodextrins and enantiomeric separations of drugs by liquid chromatography and capillary electrophoresis: basic principles and new developments. | Investigation of individual drug enantiomers is required in pharmacokinetic and pharmacodynamic studies of drugs with a chiral centre. Cyclodextrins (CDs) are extensively used in high-performance liquid chromatography as stationary phases bonded to a solid support or as mobile phase additives in HPLC and capillary elec... |
9016659 | Variegated expression of a globin transgene correlates with chromatin accessibility but not methylation status. | There are now many mammalian examples in which single cell assays of transgene activity have revealed variegated patterns of expression. We have previously reported that transgenes in which globin regulatory elements drive the lacZ reporter gene exhibit variegated expression patterns in mouse erythrocytes, with transge... |
9016655 | Probing the role of the ATP-operated clamp in the strand-passage reaction of DNA gyrase. | The high-resolution structure of the 43 kDa N-terminal fragment of the DNA gyrase B protein shows a large cavity within the protein dimer. The approximate size of this cavity is 20 A, suggesting it could accommodate a DNA helix. Computer-modelling studies of this cavity suggest that it contains a constriction, reducing... |
9016653 | High resolution footprinting of a type I methyltransferase reveals a large structural distortion within the DNA recognition site. | The type I DNA methyltransferase M.EcoR124I is a multi-subunit enzyme that binds to the sequence GAAN6RTCG, transferring a methyl group from S-adenosyl methionine to a specific adenine on each DNA strand. We have investigated the protein-DNA interactions in the complex by DNase I and hydroxyl radical footprinting. The ... |
9010930 | Independent self-assembly of cadmium-binding alpha-fragment of metallothionein in Escherichia coli without participation of beta-fragment. | We examined the independent self-assembly of the alpha- and beta-fragments of human metallothionein (MT) into cadmium-binding conformation in an Escherichia coli expression system, in addition to wild-type MT expression. The expressed alpha-fragment formed independently the structure of a metal-binding cluster without ... |
9008405 | Sensitive and specific electrochemical sensors for charge-diffuse cations: use of lipophilic cyclodextrins and an enzyme relay for the determination of acetylcholine. | Lipophilic, alkylated cyclodextrins (CDs) are aromatic hosts which are excellent ionophores for reversibly binding size-matched, charge-diffuse cations. The application of lipophilic beta-CDs as ionophores for sensing acetylcholine chloride using a potentiometric ISE and an amperometric biosensor is described. Potentio... |
9007783 | Measuring health outcome in paediatrics: development of the RAHC measure of function. | <h4>Objective</h4>To develop a genetic measure of health outcome (the RAHC Measure of Function) for paediatric health services.<h4>Methodology</h4>The RAHC Measure of Function (MOF) was modified from the Child Global Assessment Scale. The utility and reliability of the MOF was then tested by inter-clinician agreement o... |
9003760 | Mutagenesis of a stacking contact in the MS2 coat protein-RNA complex. | The thermodynamic contribution of a stacking interaction between Tyr85 in MS2 coat protein and a single-stranded pyrimidine in its RNA binding site has been examined. Mutation of Tyr85 to Phe, His, Cys, Ser and Ala decreased the RNA affinity by 1-3 kcal/mol under standard binding conditions. Since the Phe, His and Cys ... |
9003756 | Giant protein kinases: domain interactions and structural basis of autoregulation. | The myosin-associated giant protein kinases twitchin and titin are composed predominantly of fibronectin- and immunoglobulin-like modules. We report the crystal structures of two autoinhibited twitchin kinase fragments, one from Aplysia and a larger fragment from Caenorhabditis elegans containing an additional C-termin... |
9117424 | Neuroprotective effects of the dopamine D2/D3 agonist pramipexole against postischemic or methamphetamine-induced degeneration of nigrostriatal neurons. | We have examined the neuroprotective efficacy of the selective dopamine (DA) D2/D3 receptor agonist pramipexole in two models of nigrostriatal (NS) degeneration. The first involves the delayed (28-day) postischemic retrograde NS degeneration that takes place in gerbils following a 10-min episode of bilateral carotid ar... |
9003371 | Evidence for regulated dimerization of cell-cell adhesion molecule (C-CAM) in epithelial cells. | C-CAM is a Ca(2+)-independent cell adhesion molecule (CAM) belonging to the immunoglobulin superfamily. Addition of chemical cross-linkers to isolated rat liver plasma membranes, intact epithelial cells and purified preparations of C-CAM stabilized one major C-CAM-containing product whose apparent molecular mass was ap... |
9003367 | Studies of the membrane topology of the rat erythrocyte H+/lactate cotransporter (MCT1). | 1. Hydrophobicity analysis of the monocarboxylate/proton cotransporter MCT1 (lactate transporter) suggests a structure with 12 transmembrane (TM) segments, presumed to be alpha-helical. 2. A series of anti-peptide antibodies have been raised against regions of the MCT1 sequence, which each recognize a polypeptide of ap... |
9003355 | Structural elucidation of XR586, a peptaibol-like antibiotic from Acremonium persicinum. | A novel peptide, XR586, has been isolated from fermentations of Acremonium persicinum (Xenova culture collection number X21488). The structure of XR586 has been elucidated by means of NMR spectroscopy, electrospray and fast-atom bombardment MS, derivatization and enzymic digestion. It has been shown to be helical by CD... |
9000010 | New loop-loop tertiary interactions in self-splicing introns of subgroup IC and ID: a complete 3D model of the Tetrahymena thermophila ribozyme. | <h4>Background</h4>Group I introns self-splice via two consecutive trans-esterification reactions in the presence of guanosine cofactor and magnesium ions. Comparative sequence analysis has established that a catalytic core of about 120 nucleotides is conserved in all known group I introns. This core is generally not s... |
8997753 | Enantiomer separation on a Chirasil-Dex-polymer-coated stationary phase by conventional and micro-packed high-performance liquid chromatography. | Polymer-coating of Chirasil-Dex (a polysiloxane-anchored permethyl-beta-cyclodextrin) on Nucleosil 300-5 followed by thermal immobilization furnishes a chiral stationary phase for enantiomer separation under reversed-phase conditions by conventional and micro-packed HPLC. |
8997751 | Migration behavior and separation of sulfonamides in capillary zone electrophoresis. I. Influence of buffer pH and electrolyte modifier. | The influence of buffer pH and electrolyte modifier on the migration behavior and separation of thirteen sulfonamides was investigated by capillary zone electrophoresis. The results indicate that precise optimization of buffer pH is crucial in improving the separation of some closely migrating sulfonamides. On the addi... |
8989886 | The maize gamma-zein sequesters alpha-zein and stabilizes its accumulation in protein bodies of transgenic tobacco endosperm. | Zeins are seed storage proteins that form accretions called protein bodies in the rough endoplasmic reticulum of maize endosperm cells. Four types of zeins, alpha, beta, gamma, and delta, aggregate in a distinctive spatial pattern within the protein body. We created transgenic tobacco plants expressing alpha-zein, gamm... |
8988638 | Steady-state kinetic and calorimetric studies on the binding of Aspergillus niger glucoamylase with gluconolactone, 1-deoxynojirimycin, and beta-cyclodextrin. | Binding equilibria of Aspergillus niger glucoamylase with its several ligands were observed to analyze the binding modes of the ligands. Steady-state kinetic studies using p-nitrophenyl alpha-glucoside as a substrate showed that 1-deoxynojirimycin, which is a mixed type inhibitor for Rhizopus glucoamylase, was a compet... |
8988025 | Competitive interaction of component enzymes with the peripheral subunit-binding domain of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus: kinetic analysis using surface plasmon resonance detection. | The interactions of the peripheral enzymes (E1, a pyruvate decarboxylase, and E3, dihydrolipoyl dehydrogenase) with the core component (E2, dihydrolipoyl acetyltransferase) of the pyruvate dehydrogenase (PDH) multienzyme complex of Bacillus stearothermophilus have been analyzed using a biosensor based on surface plasmo... |
8988013 | Endoplasmic reticulum chaperone GRP94 subunit assembly is regulated through a defined oligomerization domain. | GRP94 is an abundant, resident glycoprotein of the mammalian endoplasmic reticulum lumen and member of the hsp90 family of molecular chaperones. To identify the structure/function relationships which define the molecular basis of GRP94 activity, we have performed a structural analysis of native GRP94 and identified a d... |
8988009 | Molecular recognition by cholesterol esterase of active site ligands: structure-reactivity effects for inhibition by aryl carbamates and subsequent carbamylenzyme turnover. | Interactions of mammalian pancreatic cholesterol esterases from pig and rat with a family of aryl carbamates CnH2n+1NHCOOAr [n = 4-9; Ar = phenyl, p-X-phenyl (X = acetamido, bromo, fluoro, nitro, trifluoromethyl), 2-naphthyl, 2-tetrahydronaphthyl, estronyl] have been investigated, with an aim of delineating the ligand ... |
8987357 | Proton-dependent multidrug efflux systems. | Multidrug efflux systems display the ability to transport a variety of structurally unrelated drugs from a cell and consequently are capable of conferring resistance to a diverse range of chemotherapeutic agents. This review examines multidrug efflux systems which use the proton motive force to drive drug transport. Th... |
8986840 | Molecular recognition of pathogen attack occurs inside of plant cells in plant disease resistance specified by the Arabidopsis genes RPS2 and RPM1. | The Arabidopsis thaliana disease resistance genes RPS2 and RPM1 belong to a class of plant disease resistance genes that encode proteins that contain an N-terminal tripartite nucleotide binding site (NBS) and a C-terminal tandem array of leucine-rich repeats. RPS2 and RPM1 confer resistance to strains of the bacterial ... |
8986780 | The aphid transmission factor of cauliflower mosaic virus forms a stable complex with microtubules in both insect and plant cells. | We analyzed the distribution of the cauliflower mosaic virus (CaMV) aphid transmission factor (ATF), produced via a baculovirus recombinant, within Sf9 insect cells. Immunogold labeling revealed that the ATF colocalizes with an atypical cytoskeletal network. Detailed observation by electron microscopy demonstrated that... |
8986764 | Synthesis and biological activity of DNA damaging agents that form decoy binding sites for the estrogen receptor. | It is a goal of cancer chemotherapy to achieve the selective killing of tumor cells while minimizing toxicity to normal tissues. We describe the design of selective toxins forming DNA adducts that attract the estrogen receptor (ER), a transcription factor that is overexpressed in many human breast and ovarian tumors. T... |
8986762 | Inhibiting transthyretin amyloid fibril formation via protein stabilization. | Transthyretin (TTR) amyloid fibril formation is observed systemically in familial amyloid polyneuropathy and senile systemic amyloidosis and appears to be the causative agent in these diseases. Herein, we demonstrate conclusively that thyroxine (10.8 microM) inhibits TTR fibril formation efficiently in vitro and does s... |
8986760 | Ferredoxin and ferredoxin-heme maquettes. | A 16-amino acid residue peptide derived from a consensus motif of natural ferredoxins incorporates a tetranuclear iron sulfur cluster under physiological conditions. Successful assembly of the [4Fe-4S]2+/1+ cluster within a monomeric peptide was demonstrated using size exclusion chromatography, UV-visible, visible CD, ... |
8986758 | Kinetic and structural analysis of mutant CD4 receptors that are defective in HIV gp120 binding. | The T-cell antigen coreceptor CD4 also serves as the receptor for the envelope glycoprotein gp120 of HIV. Extensive mutational analysis of CD4 has implicated residues from a portion of the extracellular amino-terminal domain (D1) in gp120 binding. However, none of these proteins has been fully characterized biophysical... |
8985143 | Removal of substrate inhibition in a lactate dehydrogenase from human muscle by a single residue change. | High concentrations of ketoacid substrates inhibit most natural hydroxyacid dehydrogenases due to the formation of an abortive enzyme-NAD+-ketoacid complex. It was postulated that this substrate inhibition could be eliminated from lactate dehydrogenases if the rate of NAD+ dissociation could be increased. An analysis o... |
8982828 | The relationship between gut-derived bacteria and the development of the multiple organ dysfunction syndrome. | Abnormal colonisation, infections of gut origin and bacterial translocation are all signs of gut failure that have been hypothesised as being implicated in the pathogenesis of the multiple organ dysfunction syndrome (MODS). We have summarised published experimental and clinical studies that have tried to correlate the ... |
8982684 | Postischemic administration of adenosine amine congener (ADAC): analysis of recovery in gerbils. | Although adenosine receptor-based treatment of cerebral ischemia and other neurodegenerative disorders has been frequently advocated, cardiovascular side effects and an uncertain therapeutic time window of such treatment have constituted major obstacles to clinical implementation. Therefore, we have investigated the ne... |
8981924 | Spinal cord adenosine receptor stimulation in rats inhibits peripheral neutrophil accumulation. The role of N-methyl-D-aspartate receptors. | The effect of spinal adenosine receptor ligation on peripheral leukocyte accumulation was studied in two rat models of inflammation. Neutrophil infiltration into dermal inflammatory sites was signficantly reduced by adenosine A1 receptor agonists injected through intrathecal catheters. These effects were reversed by N-... |
8981649 | [The effect of brain-derived neurotrophic factor on regeneration of nerve fibers after crush injury--morphometric evaluation]. | Brain-derived neurotrophic factor (BDNF) is produced in Schwann cells and fibroblasts in the peripheral nerve, and is considered to play an important role in survival, maintenance, development and repair of the peripheral neuron. In this study, the effect of human recombinant BDNF on the regeneration of nerve fibers fo... |
8980983 | The role of the host defence response in the progression and outcome of ARDS: pathophysiological correlations and response to glucocorticoid treatment. | The host defence response (HDR) to insults is similar regardless of the tissue involved and consists of an interactive network of simultaneously activated pathways that act in synergy to increase the host's chance of survival. Among this cascade of integrated pathways, three aspects of the HDR, inflammation, coagulatio... |
8980638 | Comparative studies of the fate of free and liposome-entrapped hydroxypropyl-beta-cyclodextrin/drug complexes after intravenous injection into rats: implications in drug delivery. | Inclusion complexes of 14C-labelled hydroxypropyl-beta-cyclodextrin (HP beta-CD) with tritiated dehydroepiandrosterone (DHEA), retinol (RET) and dexamethasone (DEX) were entrapped in the aqueous phase of liposomes composed of distearoyl phosphatidylcholine. Incubation of liposome-entrapped complexes in the presence of ... |
8980387 | Tumour-localising and -photosensitising properties of a novel zinc(II) octadecylphthalocyanine. | 1,4,8,11,15,18,22,25-Octadecylphthalocyaninato zinc(II), ZnODPc, incorporated into a Cremophor emulsion, was assayed for its pharmacokinetic and phototherapeutic properties in Balb/c mice bearing an intramuscularly transplanted MS-2 fibrosarcoma. The phthalocyanine was injected intravenously (i.v.) in three doses, i.e.... |
8980139 | Phosphoenzyme formation by purified, reconstituted copper ATPase of Enterococcus hirae. | The Enterococcus hirae CopB ATPase serves in the secretion of excess copper from cells and belongs to the recently discovered, new class of heavy metal transport ATPases. We here report the affinity purification of CopB to near homogeneity and its reconstitution into phospholipid vesicles. In these proteoliposomes, the... |
8978815 | A novel ubiquitin-like modification modulates the partitioning of the Ran-GTPase-activating protein RanGAP1 between the cytosol and the nuclear pore complex. | Ran is a nuclear Ras-like GTPase that is required for the bidirectional transport of proteins and ribnucleoproteins across the nuclear pore complex (NPC). A key regulator of the Ran GTP/GDP cycle is the 70-kD Ran-GTPase-activating protein RanGAP1. Here, we report the identification and localization of a novel form of R... |
8978686 | Growth arrest by the cyclin-dependent kinase inhibitor p27Kip1 is abrogated by c-Myc. | We show here that c-Myc antagonizes the cyclin-dependent kinase (CDK) inhibitor p27Kip1. p27 expressed from recombinant retroviruses in Rat1 cells associated with and inhibited cyclin E/CDK2 complexes, induced accumulation of the pRb and p130 proteins in their hypophosphorylated forms, and arrested cells in G1. Prior e... |
8978667 | Dimerization of TWIK-1 K+ channel subunits via a disulfide bridge. | TWIK-1 is a new type of K+ channel with two P domains and is abundantly expressed in human heart and brain. Here we show that TWIK-1 subunits can self-associate to give dimers containing an interchain disulfide bridge. This assembly involves a 34 amino acid domain that is localized to the extracellular M1P1 linker loop... |
8978664 | The plastocyanin binding domain of photosystem I. | The molecular recognition between plastocyanin and photosystem I was studied. Photosystem I and plastocyanin can be cross-linked to an active electron transfer complex. Immunoblots and mass spectrometric analysis of proteolytic peptides indicate that the two negative patches conserved in plant plastocyanins are cross-l... |
8978051 | Functional and genetic characterization of the oligomerization and DNA binding properties of the Drosophila doublesex proteins. | The doublesex (dsx) gene of Drosophila melanogaster encodes both male-specific (DSXM) and female-specific (DSXF) polypeptides, which are required for normal differentiation of numerous sexually dimorphic somatic traits. The DSX polypeptides are transcription factors and have been shown previously to bind through a zinc... |
8978028 | CDP1, a novel Saccharomyces cerevisiae gene required for proper nuclear division and chromosome segregation. | To identify new gene products involved in chromosome segregation, we isolated Saccharomyces cerevisiae mutants that require centromere binding factor I (Cbf1p) for viability. One Cbf1p-dependent mutant (denoted cdp1-1) was selected for further analysis. The CDP1 gene encodes a novel 125-kD protein that is notably simil... |
8977106 | Inhibition by penem of processing peptidases from cyanobacteria and chloroplast thylakoids. | Proteins targeted to the thylakoid lumen of plants and cyanobacteria and the periplasmic space of cyanobacteria are synthesised with N-terminal presequences which are removed following translocation across the membrane. These presequences are thought to direct translocation of the preprotein by a sec-type pathway. Dete... |
8976552 | Protein clefts in molecular recognition and function. | One of the primary factors determining how proteins interact with other molecules is the size of clefts in the protein's surface. In enzymes, for example, the active site is often characterized by a particularly large and deep cleft, while interactions between the molecules of a protein dimer tend to involve approximat... |
8973638 | An insect-specific toxin from Centruroides noxius Hoffmann. cDNA, primary structure, three-dimensional model and electrostatic surface potentials in comparison with other toxin variants. | Scorpion toxins acting on sodium channels differ in their specificity. Toxic peptides specific towards mammals and arthropods (insects and/or crustaceans) have been described. Because of the similar three-dimensional fold of these peptides, the molecular base of their specificity is thought to reside in certain differe... |
8973556 | Partial characterization of the C-terminal non-collagenous domain (NC1) of collagen type X. | Collagen type X is composed of three identical alpha 1(X) chains of 59 kDa, each containing a triple-helical region of 45 kDa flanked by a short N-terminal sequence and a larger non-collagenous C-terminal (NC1) domain of approx. 15 kDa. Collagen type X molecules can associate via their C-termini to form a regular hexag... |
8973546 | Comparative studies on the 5-aminolaevulinic acid dehydratases from Pisum sativum, Escherichia coli and Saccharomyces cerevisiae. | 5-Aminolaevulinic acid dehydratase (ALAD) is an essential enzyme in most organisms, catalysing an inaugural step in the tetrapyrrole biosynthetic pathway, the Knorr-type condensation reaction of two molecules of 5-aminolaevulinic acid (ALA) to form the monopyrrole porphobilinogen. ALADs can be conveniently separated in... |
8973539 | Mammalian mitochondrial beta-oxidation. | The enzymic stages of mammalian mitochondrial beta-oxidation were elucidated some 30-40 years ago. However, the discovery of a membrane-associated multifunctional enzyme of beta-oxidation, a membrane-associated acyl-CoA dehydrogenase and characterization of the carnitine palmitoyl transferase system at the protein and ... |
8972875 | A tri-hybrid system for the analysis and detection of RNA--protein interactions. | A modification of the two-hybrid system is described for the in vivo reconstruction of specific RNA-protein interactions. In this tri-hybrid system, the DNA binding and transcription activation domains of the yeast transcriptional activator GAL4 are brought together via the interaction of recombinant fusion proteins wi... |
8972869 | Octamer independent activation of transcription from the kappa immunoglobulin germline promoter. | Previous analyses of immunoglobulin V region promoters has led to the discovery of a common octamer motif which is functionally important in the tissue-specific and developmentally regulated transcriptional activation of immunoglobulin genes. The germline promoters (Ko) located upstream of the J region gene segments of... |
8972851 | Watson-Crick base-pairing properties of bicyclo-DNA. | A series of sequences of the DNA analog bicyclo-DNA, 6-12 nucleotides in length and containing all four natural nucleobases, were prepared and their Watson-Crick pairing properties with complementary RNA and DNA, as well as in its own series, were analyzed by UV-melting curves and CD-spectroscopy. The results can be su... |
8972633 | Photochemistry and photophysical properties of novel, unsymmetrically substituted metallophthalocyanines. | A series of novel, unsymmetrically substituted metallo-phthalocyanines was synthesized, along with their symmetrically substituted analogs, and the effects of structure and metal substitution on their photophysical and photoredox properties were investigated. The macrocycles were synthesized using a mixed-condensation ... |
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