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8954925 | Polysulfated derivatives of beta-cyclodextrin and myo-inositol as potent inhibitors of the interaction between L-selectin and peripheral addressin: implying a requirement for highly clustered sulfate groups. | We have utilized an in vitro assay that measures the binding of an L-selectin-human Fc chimera (LS-Fc) to [35S]sulfate labelled peripheral addressin (PNAd), a 120 kDa glycoprotein ligand for L-selectin in porcine lymph nodes, to evaluate inhibitory properties of a small group of sulfated derivatives of beta-cyclodextri... |
8971011 | Intracellular expression of single-chain variable fragments to inhibit early stages of the viral life cycle by targeting human immunodeficiency virus type 1 integrase. | Integration of viral DNA into a chromosome of the infected host cell is required for efficient replication of a retroviral genome, and this reaction is mediated by the virus-encoded enzyme integrase (IN). As IN plays a pivotal role in establishing infection during the early stages of the retroviral life cycle, it is an... |
8970972 | Immunogenicity of an aphthovirus chimera of the glycoprotein of vesicular stomatitis virus. | An oligodeoxynucleotide coding for amino acids 139 through 149 of antigenic site A (ASA) of the VP1 capsid protein of the foot-and-mouth disease virus C3 serotype (FMDV C3) was inserted into three different in-frame sites of the vesicular stomatitis virus New Jersey serotype (VSV-NJ) glycoprotein (G) gene cDNA present ... |
8970964 | Resistance of human immunodeficiency virus type 1 to neutralization by natural antisera occurs through single amino acid substitutions that cause changes in antibody binding at multiple sites. | The ability of human immunodeficiency virus type 1 (HIV-1) to replicate in the presence of strong immune responses to the virus may be due to its high mutation rate, which provides envelope gene variability for selection of neutralization-resistant variants. Understanding neutralization escape mechanisms is therefore i... |
8970951 | Type, prevalence, and significance of core promoter/enhancer II mutations in hepatitis B viruses from immunosuppressed patients with severe liver disease. | Little is known about the functional significance of hepatitis B virus (HBV) sequence heterogeneity. Here we analyzed the type, frequency, and function of mutations in the core promoter/enhancer II region of HBV in immunosuppressed patients. The major HBV population in immunosuppressed patients with severe liver diseas... |
8970557 | Effect of lung contusion on surfactant composition in multiple-trauma patients. | <h4>Objective</h4>The aim of this study was to investigate alterations of the surfactant system in multiple-trauma patients (MTP) with lung contusion and the influence of single- or multiple-organ dysfunction syndrome (OF/MOF) on the surfactant system.<h4>Setting</h4>University hospital, trauma-intensive care unit.<h4>... |
8970153 | Is outer arm dynein intermediate chain 1 multifunctional? | The outer arm dynein of sea urchin sperm axoneme contains three intermediate chains (IC1, IC2, and IC3; M(r) 128,000, 98,000, and 74,000, respectively). IC2 and IC3 are members of the WD family; the WD motif is responsible for a protein-protein interaction. We describe here the molecular cloning of IC1. IC1 has a uniqu... |
8968618 | Molecular dynamics of the transition from L-selectin- to beta 2-integrin-dependent neutrophil adhesion under defined hydrodynamic shear. | Homotypic adhesion o2 neutrophils stimulated with chemoattractant is analogous to capture on vascular endothelium in that both processes depend on L-selectin and beta 2-integrin adhesion receptors. Under hydrodynamic shear, cell adhesion requires that receptors bind sufficient ligand over the duration of intercellular ... |
8968615 | Theory, design, and characterization of a microdialysis flow cell for Raman spectroscopy. | The theory, design, and application of a dialysis flow cell for Raman spectroscopy are described. The flow cell permits rapid collection of Raman spectra concurrent with the efflux of small solute molecules or ions into a solution of macromolecules and is well suited to acquisition of data during hydrogen-isotope excha... |
8968610 | Calcium binding decreases the stokes radius of calmodulin and mutants R74A, R90A, and R90G. | Calmodulin (CaM) is an intracellular cooperative calcium-binding protein essential for activating many diverse target proteins. Biophysical studies of the calcium-induced conformational changes of CaM disagree on the structure of the linker between domains and possible orientations of the domains. Molecular dynamics st... |
8968596 | The interaction of polyphenols with bilayers: conditions for increasing bilayer adhesion. | Because proteins and other molecules with a high polyphenol content are commonly involved in adhesion processes, we are investigating the interactions between polyphenols and biological materials. A naturally occurring polyphenol that binds a variety of proteins and lipids is tannic acid (TA), which contains five digal... |
8968588 | Valence selectivity of the gramicidin channel: a molecular dynamics free energy perturbation study. | The valence selectivity of the gramicidin channel is examined using computer simulations based on atomic models. The channel interior is modeled using a gramicidin-like periodic poly (L,D)-alanine beta-helix. Free energy perturbation calculations are performed to obtain the relative affinity of K+ and Cl- for the chann... |
8968582 | On the structural basis for ionic selectivity among Na+, K+, and Ca2+ in the voltage-gated sodium channel. | Voltage-sensitive sodium channels and calcium channels are homologous proteins with distinctly different selectivity for permeation of inorganic cations. This difference in function is specified by amino acid residues located within P-region segments that link presumed transmembrane elements S5 and S6 in each of four r... |
8968566 | Molecular dynamics simulations of a protein on hydrophobic and hydrophilic surfaces. | Molecular dynamics simulations have been used to investigate the behavior of the peripheral membrane protein, cytochrome c, covalently tethered to hydrophobic (methyl-terminated) and hydrophilic (thiol-terminated) self-assembled monolayers (SAMs). The simulations predict that the protein will undergo minor structural c... |
8962166 | Isolation and characterization of a tobacco mosaic virus-inducible myb oncogene homolog from tobacco. | Salicylic acid (SA) plays an important role in signaling the activation of plant defense responses against pathogen attack including induction of pathogenesis-related (PR) proteins. To gain further insight into the SA-mediated signal transduction pathway, we have isolated and characterized a tobacco mosaic virus (TMV)-... |
8962108 | cag, a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factors. | cagA, a gene that codes for an immunodominant antigen, is present only in Helicobacter pylori strains that are associated with severe forms of gastroduodenal disease (type I strains). We found that the genetic locus that contains cagA (cag) is part of a 40-kb DNA insertion that likely was acquired horizontally and inte... |
8962084 | Proton long-range migration along protein monolayers and its consequences on membrane coupling. | It has been shown with lipid layers and more recently with purple membranes that protons have slow surface-to-bulk transfer. This results in long-range proton lateral conduction along membranes. We report here that such lateral transfer can take place along a pure protein film. It is strongly controlled by the packing.... |
8962052 | Protein engineering of Bacillus thuringiensis delta-endotoxin: mutations at domain II of CryIAb enhance receptor affinity and toxicity toward gypsy moth larvae. | Substitutions or deletions of domain II loop residues of Bacillus thuringiensis delta-endotoxin CryIAb were constructed using site-directed mutagenesis techniques to investigate their functional roles in receptor binding and toxicity toward gypsy moth (Lymantria dispar). Substitution of loop 2 residue N372 with Ala or ... |
8962048 | Biosynthesis of vitamin B12: concerning the identity of the two-carbon fragment eliminated during anaerobic formation of cobyrinic acid. | It has been proved that, during anaerobic biosynthesis of the corrin macrocycle, the two-carbon fragment excised from the precursor, precorrin-3, is acetaldehyde, which originates from C-20 and its attached methyl group. This apparently contradictory finding is rationalized in terms of the subsequent enzymatic oxidatio... |
8962030 | Symmetries throughout organic evolution. | The biological realm has inherited symmetries from the physicochemical realm, but with the increasing complexity at higher phenomenological levels of life, some inherited symmetries are broken while novel symmetries appear. These symmetries are of two types, structural and operational. Biological novelties result from ... |
8961939 | Artificial chaperone-assisted refolding of denatured-reduced lysozyme: modulation of the competition between renaturation and aggregation. | Conditions that promote renaturation of an unfolded protein also promote protein aggregation, in many cases, because these competing intramolecular and intermolecular processes are driven by similar networks of noncovalent interactions. The GroEL/GroES system and related biological chaperones facilitate the renaturatio... |
8955120 | Cryptic antigenic determinants on the extracellular pyruvate dehydrogenase complex/mimeotope found in primary biliary cirrhosis. A probe by affinity mass spectrometry. | Affinity mass spectrometry (AMS) was used to evaluate the structural diversity of the E2 component of pyruvate dehydrogenase complex (PDC) in normal and diseased liver cells, including those from patients with the autoimmune disease primary biliary cirrhosis (PBC). Two different antibodies to PDC-E2, the immunodominant... |
8955113 | The raw starch binding domain of cyclodextrin glycosyltransferase from Bacillus circulans strain 251. | The E-domain of cyclodextrin glycosyltransferase (CGTase) (EC 2.4.1.19) from Bacillus circulans strain 251 is a putative raw starch binding domain. Analysis of the maltose-dependent CGTase crystal structure revealed that each enzyme molecule contained three maltose molecules, situated at contact points between protein ... |
9124847 | Antimycobacterial action of thiolactomycin: an inhibitor of fatty acid and mycolic acid synthesis. | Thiolactomycin (TLM) possesses in vivo antimycobacterial activity against the saprophytic strain Mycobacterium smegmatis mc2155 and the virulent strain M. tuberculosis Erdman, resulting in complete inhibition of growth on solid media at 75 and 25 micrograms/ml, respectively. Use of an in vitro murine macrophage model a... |
8955398 | FtsA is localized to the septum in an FtsZ-dependent manner. | The localization of the cell division protein FtsA in E. coli was examined. FtsA was found to localize to the septum in a ring pattern as previously shown for FtsZ. The localization of FtsA was completely dependent on the localization of FtsZ. Under a variety of conditions that prevented formation of the Z ring, FtsA w... |
8955388 | Action at a distance for negative control of transcription of the glpD gene encoding sn-glycerol 3-phosphate dehydrogenase of Escherichia coli K-12. | Aerobic sn-glycerol 3-phosphate dehydrogenase is a cytoplasmic membrane-associated respiratory enzyme encoded by the glpD gene of Escherichia coli. The glpD operon is tightly controlled by cooperative binding of the glp repressor to tandem operators (O(D)1 and O(D)2) that cover the -10 promoter element and 30 bp downst... |
8954102 | Self-assembly of the brain MAP-2 microtubule-binding region into polymeric structures resembling Alzheimer filaments. | The neuronal microtubule-associated protein known as MAP-2 has not been considered to be a subunit of paired helical filaments (PHFs) in neurofibrillary tangles seen in Alzheimer's Disease. We now describe the assembly of paired helical filament-like structures from MAP-2's 203-residue microtubule-binding region (MTBR)... |
8953704 | Complete microbial degradation of both enantiomers of the chiral herbicide mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propionic acid] in an enantioselective manner by Sphingomonas herbicidovorans sp. nov. | Sphingomonas herbicidovorans MH (previously designated Flavobacterium sp. strain MH) was able to utilize the chiral herbicide (RS)-2-(4-chloro-2-methylphenoxy)propionic acid (mecoprop) as the sole carbon and energy source. When strain MH was offered racemic mecoprop as the growth substrate, it could degrade both the (R... |
8952473 | 6-deoxyerythronolide B synthase 1 is specifically acylated by a diketide intermediate at the beta-ketoacyl-acyl carrier protein synthase domain of module 2. | We have used 6-deoxyerythronolide B synthase (DEBS) as a model system to investigate molecular recognition by a modular polyketide synthase (PKS). DEBS consists of three proteins (DEBS1, -2, and -3) that biosynthesize the polyketide skeleton of the antibiotic erythromycin from propionyl-CoA and methylmalonyl-CoA. Activ... |
8952461 | The central domain of colicin N possesses the receptor recognition site but not the binding affinity of the whole toxin. | Colicin N is a three-domain pore-forming colicin which kills enterobacterial cells following an initial binding to its receptor, the outer membrane porin OmpF. The receptor-binding domain of colicin N alone, and attached to the translocation domain, was overexpressed and purified using a hexahistidine tag. The receptor... |
8947562 | Reduction of type V collagen using a dominant-negative strategy alters the regulation of fibrillogenesis and results in the loss of corneal-specific fibril morphology. | A number of factors have been implicated in the regulation of tissue-specific collagen fibril diameter. Previous data suggest that assembly of heterotypic fibrils composed of two different fibrillar collagens represents a general mechanism regulating fibril diameter. Specifically, we hypothesize that type V collagen is... |
8946856 | Deep penetration of an alpha-helix into a widened RNA major groove in the HIV-1 rev peptide-RNA aptamer complex. | A combined NMR-molecular dynamics approach has been applied to determine the solution structure of a HIV-1 17-mer rev peptide bound to its 35-mer high affinity RNA aptamer binding site. Complex formation involves adaptive binding with the alpha-helical arginine-rich basic rev peptide targeting a widened RNA major groov... |
8943337 | Recombination induced by triple-helix-targeted DNA damage in mammalian cells. | Gene therapy has been hindered by the low frequency of homologous recombination in mammalian cells. To stimulate recombination, we investigated the use of triple-helix-forming oligonucleotides (TFOs) to target DNA damage to a selected site within cells. By treating cells with TFOs linked to psoralen, recombination was ... |
8941328 | Definition of the RRE binding and activation domains of the caprine arthritis encephalitis virus Rev protein. | Caprine arthritis encephalitis virus (CAEV) is a lentivirus which is closely related by nucleotide sequence and biological properties to visna virus and is more distantly related to the human AIDS virus, HIV-1. Previous studies indicated that the CAEV Rev protein (Rev-C) functions as a trans-activator of mRNA cytoplasm... |
8940171 | Contrasting enzymatic activities of topoisomerase IV and DNA gyrase from Escherichia coli. | DNA gyrase and topoisomerase IV (Topo IV) have distinct roles as unlinking enzymes during DNA replication despite 40% sequence identity between them. DNA gyrase unlinks replicating DNA by introducing negative supercoils while Topo IV decatenates the two daughter molecules. For this study, we measured the rates of unlin... |
8940267 | Spectrum of mutations in the COL4A5 collagen gene in X-linked Alport syndrome. | Alport syndrome is a mainly X-linked hereditary disease of basement membranes that is characterized by progressive renal failure, deafness, and ocular lesions. It is associated with mutations of the COL4A5 gene located at Xq22 and encoding the alpha5 chain of type IV collagen. We have screened 48 of the 51 exons of the... |
8922432 | Dopamine and spatial working memory in rats and monkeys: pharmacological reversal of stress-induced impairment. | The anxiogenic benzodiazepine inverse agonist FG7142 increases dopamine turnover in rodent prefrontal cortex but not in other dopamine terminal field areas. FG7142-induced increases in prefrontal cortical dopamine receptor stimulation impair prefrontal-dependent, but not nonprefrontal-dependent, cognitive tasks in rats... |
8922421 | The expression pattern of the transcription factor Phox2 delineates synaptic pathways of the autonomic nervous system. | Many transcription factors, and most prominently among them, homeodomain proteins, are expressed in specific groups of cells in the developing nervous system in patterns that suggest their involvement in neural fate determination. How various aspects of neural identity are controlled by such transcription factors, or s... |
38239267 | Recent Developments in Selective Agonists and Antagonists Acting at Purine and Pyrimidine Receptors. | The SAR at adenosine (P<sub>1</sub>) and ATP (P<sub>2</sub>) receptors is reviewed, with emphasis on recently developed selective agonists and antagonists. These include partial (e.g., N<sup>6</sup>-ethyl-8-cyclopentylaminoadenosine) and full A<sub>1</sub> agonists (e.g., NNC 21-0136, 2-chloro-N<sup>6</sup>-[(<i>R</i>)... |
38235168 | Avian and Human Homologues of the P2Y<sub>1</sub> Receptor: Pharmacological, Signaling, and Molecular Properties. | [Table: see text] The P2Y receptor on turkey erythrocyte membranes was the first P2 receptor to be shown to activate phospholipase C (PLC) in a strictly guanine nucleotide-dependent manner and remains the only G protein-coupled P2 receptor for which G protein-coupling kinetics have been defined. This membrane receptor ... |
30897681 | The role of acidic residues of plastocyanin in its interaction with cytochrome ƒ. | The role of the acidic patches of spinach plastocyanin in the interaction with a soluble form of turnip cytochrome ƒ was studied by a combination of site-directed mutagenesis, NMR spectroscopy and kinetic analysis. The charge of the two 'eastern' patches, consisting of conserved acidic residues 42-45 and 59-61 respecti... |
21619264 | Chromatography of mechanically interlocked molecular compounds. | Catenanes and rotaxanes are molecules composed of mechanically interlocked components which are not linked to each other by covalent bonds. These molecular assemblies behave as discrete molecules with defined properties significantly different from those of the parent "free" components. High-performance liquid chromato... |
21619250 | Determination of the enantiomeric composition of chiral amines based on the quenching of the fluorescence of a chiral calixarene. | The synthesis of three chiral calixarene derivatives is described. One of these, an (S)-di-2-naphthylprolinol tetramer, is shown to exhibit significant ability to discriminate between enantiomers of 1-phenylethylamine (PEA) and norephedrine on the basis of the quenching of the (S)-di-2-naphthylprolinol fluorescence emi... |
17029807 | Thermodynamics of sequence-specific protein-DNA interactions. | The molecular recognition processes in sequence-specific protein-DNA interactions are complex. The only feature common to all sequence-specific protein-DNA structures is a large interaction interface, which displays a high degree of complementarity in terms of shape, polarity and electrostatics. Many molecular mechanis... |
8954683 | Size-Exclusion Chromatography of Carboxyl-terminated Dendrimers as a Model for Permeation of Charged Particles into Like-Charged Cavities | In order to examine the permeation of small charged colloids into cavities of like charge, size-exclusion chromatography was carried out with carboxyl-terminated dendritic polymers on a porous glass stationary phase. Chromatographic partition coefficients KSEC were measured for solute diameters ranging from 2 to 8 nm, ... |
11667800 | Synthesis of N-Confused Porphyrin Analogues by beta-Azafulvenone Tetramerization. | beta-Azafulvenones 16 and 33 were generated from 14 or 18 and 31 or 37, respectively, and directly observed by IR spectroscopy. These heterocyclic ketenes tetramerize to the macrocycles 20 and 34. |
11667798 | Conformation of 18-Crown-5 and Its Influence on Complexation with Alkali and Ammonium Cations: Why 18-Crown-5 Binds More Than 1000 Times Weaker Than 18C6. | Stability constants of potassium, sodium, and benzylammonium salts with 18C5 are determined in water, methanol, and acetonitrile by potentiometric titrations. The corresponding free energies DeltaG agree within the error with those obtained from calorimetric titrations. In comparison to 18C6 the DeltaG values are lower... |
11666888 | Formation and X-ray Structures of PCP Ligand Based Platinum(II) and Palladium(II) Macrocycles. | The coordination behavior prior to C-M bond formation of the chelating aromatic PCP substrate DPPMH (3; DPPMH = 1,3-bis((diphenylphosphino)methylene)mesitylene) has been studied in order to determine the factors which control the complex formation of such ligands. Reacting 3 with (RCN)(2)MCl(2) (R = Me, Ph; M = Pd, Pt)... |
11666855 | Molecular Recognition of Amino Acids by Copper(II) Complexes of 6(A),6(X)-Diamino-6(A),6(X)-dideoxy-beta-cyclodextrin (X = B, C, D). | The three regioisomers of beta-cyclodextrin 6-difunctionalized with NH(2) groups (6(A),6(X)-diamino-6(A),6(X)-dideoxy-beta-cyclodextrin, A,X-CDNH(2), X = B, C, or D) were synthesized. Their binary and ternary copper(II) complexes with amino acids were characterized by ESR and electronic spectroscopy. Furthermore, the b... |
11666848 | Luminescence Properties of Platinum(II) Dithiooxamide Compounds. | Tight contact ion pairs of general formula {Pt(H(2)-R(2)-dto)(2)(2+),(X(-))(2)} have been prepared, and their absorption spectra and luminescence properties (at room temperature in dichloromethane fluid solution and at 77 K in butyronitrile rigid matrix) have been studied (dto = dithiooxamide; R = methyl, X = Cl (1); R... |
12579199 | NTP Toxicology and Carcinogenesis Studies of Phenolphthalein (CAS No. 77-09-8) in F344/N Rats and B6C3F1 Mice (Feed Studies). | Phenolphthalein is used as a laboratory reagent and acid-base indicator and in over-the-counter laxative preparations. The National Cancer Institute nominated phenolphthalein for study because of its widespread use as a component in numerous laxative preparations and the lack of adequate testing for carcinogenicity in ... |
15299574 | X-ray structure of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011. Comparison of two independent molecules at 1.8 A resolution. | Cyclodextrin glucanotransferase (CGTase) is an enzyme which produces cyclodextrins by the degradation of starch. The enzyme from alkalophilic Bacillus sp. 1011, consisting of 686 amino acid residues, was crystallized from the solution containing 20% PEG 3000 and 20% 2-propanol at pH 5.6 adjusted with citrate buffer. Th... |
15299570 | Structure of the Fab fragment of a monoclonal antibody specific for carcinoembryonic antigen. | The three-dimensional structure of the Fab fragment of the murine monoclonal antibody A5B7, which is specific for carcinoembryonic antigen (CEA) a protein expressed on carcinoma cell surfaces, has been determined. The structure was solved by molecular replacement and has been refined to an R factor for 21.2% (all data ... |
9384720 | Chiral separations with coated and uncoated capillaries. | Chiral resolution depends on the time the two enantiomers have for active migration within the capillary. Consequently, the magnitude of the electroosmotic flow (EOF) has a paramount influence on resolution, especially for chiral acidic compounds (counterosmotic migration). In this case, when the mobility of the analyt... |
9230465 | The use of crown ethers in peptide chemistry-V. Solid-phase synthesis of peptides by the fragment condensation approach using crown ethers as non-covalent protecting groups. | We have previously described the conditions by which peptide synthesis by the solid-phase fragment condensation approach can be carried out using crown ethers as non-covalent protection for the N alpha-amino group. Here we demonstrate that the procedure can be extended to large, partially protected peptide fragments po... |
9273747 | [Effect of radiation on the structure of model and natural biomembranes using differential scanning calorimetry]. | A novel method of DSC studies of biomembranes has been proposed, making it possible to investigate the influence of ionizing radiations upon the structure of water dispersions of phospholipids and phospholipid-based systems of natural origin, e.g., rat liver homogenates and erythrocyte ghosts. It is shown that in certa... |
9048422 | Self-assembly of cyclic peptides on a dendrimer: multiple cyclic antigen peptides. | Multiple cyclic antigen peptides (McAPs) are dendrimers that have branched, multiple closed-chain architectures. We describe an approach for their stepwise, solid-phase synthesis that permits a self-assembly of cyclization reactions of a McAP with four copies of cyclic peptides in solution after their cleavage from the... |
9038080 | Parenteral formulation of Flavopiridol (NSC-649890). | Flavopiridol [5,7-dihydroxy-8-(4-N-methyl-2-hydroxypyridyl)-6' -chloroflavone hydrochloride] is a flavonoid with weak electrolyte properties and an intrinsic aqueous solubility of 0.024 mg/mL. Neither cosolvency complexation, nor pH control alone can produce an acceptable 10 mg/mL formulation that will not precipitate ... |
9027998 | Synthesis and expression of the gene coding for noxiustoxin, a K+ channel-blocking peptide from the venom of the scorpion Centruroides noxius. | A set of six synthetic overlapping oligonucleotides coding for noxiustoxin were coupled into a continuous DNA fragment by means of recursive polymerase chain reaction. The polymerase chain reaction product was digested with SalI and HindIII, ligated into the E, coli vector pCSP 105 and expressed as a fusion protein. Th... |
9007281 | How do antibodies and lectins recognize histo-blood group antigens? A 3D-QSAR study by comparative molecular field analysis (CoMFA). | The cross-reaction patterns of nine antibodies and three lectins against 12 H type 2 related oligosaccharides have been analysed by means of 3D-QSAR study. Three-dimensional descriptors of the molecular properties have been used in comparative molecular field analysis (CoMFA). Three different alignments were considered... |
9007279 | Macromolecular recognition: effect of multivalency in the inhibition of binding of yeast mannan to concanavalin A and pea lectins by mannosylated dendrimers. | The synthesis and binding properties of a new family of high affinity alpha-D-mannopyranoside ligands are described. The synthesis of the new multivalent ligands is based on the scaffolding of multiantennary branches of L-lysine residues having electrophilic N-chloroacetylated end groups as core structures. An alpha-D-... |
8990491 | Physiological effects of a novel bioactive agent. | Urinary bladder smooth muscle contraction can be evaluated using field stimulation (neurohumoral transmission), carbachol (muscarinic stimulation), and KCl (direct membrane depolarization). We recently evaluated the activity of a novel organic chemical, macrocycle-1, on the contractile responses of the bladder to field... |
8982852 | Gelation of the lens capsule type IV collagen solution at a neutral pH. | It is known that the type IV collagen extracted from EHS tumor assembles under a physiological condition, but not in a gel form. The EHS type IV collagen requires the other basement membrane components, laminin1, heparansulfate proteoglycan, and/or nidogen for gelation. On the other hand, Muraoka et al. reported that t... |
8973344 | Identification and analysis of the u6 small nuclear RNA gene from Entamoeba histolytica. | Among the small nuclear RNAs (snRNAs) involved in the spliceosomal processing of pre-mRNA, U6 is the most conserved. As a first evidence for the presence of the splicing machinery in the amitochondrial protozoan Entamoeba histolytica (Eh), we have cloned the u6 snRNA gene. We find that in this organism u6 is a single c... |
8962501 | Separation of chiral polychlorinated biphenyls by micellar electrokinetic chromatography using beta- and gamma-cyclodextrin mixtures in the separation buffer. | Chiral polychlorinated biphenyls (PCBs) 45, 84, 88, 91, 95, 132, 136, 139, 149, 171, 183 and 196 were separated each in its two enantiomers by cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC). Mixtures of beta- and gamma-cyclodextrins were used as chiral modifiers in a 2-(N-cyclohexylamino)ethanes... |
8962447 | Inclusion of the main pheromone component of Dacus oleae, 1,7-dioxaspiro[5,5]undecane, in beta-cyclodextrin. | The complex beta-cyclodextrin-1,7-dioxaspiro[5,5]undecane nonahydrate, C42H70O35.C9H16O2.9H2O, belongs to the class of beta-cyclodextrin dimeric-type complexes. The racemic guest molecule is present in a disordered position. Both enantiomers are located in two different regions inside the channel formed by the host dim... |
8961164 | Anti-inflammatory, analgesic and ulcerogenic properties of S-(+)-ibuproxam, racemic ibuproxam-beta-cyclodextrin and S-(+)-ibuproxam-beta-cyclodextrin. | The anti-inflammatory, analgesic and gastric mucosal damage-inducing activities of S-(+)-ibuproxam, and S-(+)-ibuproxam-beta-cyclodextrin, new propionic acid derivatives, and racemic ibuproxam-beta-cyclodextrin were investigated in three animal models and compared with those of racemic ibuproxam, racemic ibuprofen and ... |
8953197 | Quantitative determination of tryptophan enantiomers by capillary electrophoresis. | A novel capillary electrophoretic method is reported which allows efficient detection of 0.1% L-tryptophan in the presence of the D-enantiomer. The optimised conditions employed a triethanolamine-phosphoric acid electrolyte containing alpha-cyclodextrin. The method is also capable of acceptable injection precision resu... |
8953194 | Development and validation of chiral high-performance liquid chromatographic methods for the quantitation of valsartan and of the tosylate of valinebenzyl ester. | A stereospecific HPLC method for the quantitation of CGP 49309 in samples of its corresponding enantiomer valsartan has been developed and validated. The enantiomeric separation was achieved on a 5 micron silica-bonded, alpha 1-acid glycoprotein column (Chiral AGP) with a phosphate buffer, pH 7, containing 2% (v/v) 2-p... |
8951170 | Effects of a dosing solution on the nasal absorption of non-glycosylated recombinant human granulocyte colony-stimulating factor in rats. | The nasal absorption of non-glycosylated recombinant human granulocyte colony-stimulating factor produced by Esherichia coli (E. coli-rhG-CSF) was studied in rats. We investigated the effects of the basic conditions of the dosing solution and the enhancing effects of various substances to find means to improve the nasa... |
8950489 | In vitro gene delivery by degraded polyamidoamine dendrimers. | Transfection of cultured cells has been reported using complexes between DNA and spherical cationic polyamidoamine polymers (Starburst dendrimers) that consist of primary amines on the surface and tertiary amines in the interior. The transfection activity of the dendrimers is dramatically enhanced (> 50-fold) by heat t... |
8950276 | Three-dimensional structure of the lipoyl domain from the dihydrolipoyl succinyltransferase component of the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli. | A sub-gene encoding the lipoyl domain of the dihydrolipoyl succinyltransferase polypeptide chain of the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli was over-expressed and the protein was purified uniformly labelled with 15N. The three-dimensional structure of the domain was determined by means ... |
8950270 | Guided evolution of enzymes with new substrate specificities. | A gene library was constructed coding for all possible variants of two amino acids (101, 102) in a solvent-exposed surface return loop (alpha E-beta D) of Bacillus stearothermophilus L-lactate dehydrogenase (bsLDH). All but one of 38 enzyme variants examined were thermally stable and had native-like hydrodynamic proper... |
8948485 | Role of ionic interactions in cholinesterase catalysis. | Acetylcholinesterase (AChE, EC 3.1.1.7) is an enzyme terminating the transmission of nerve impulse in synapses by rapid and selective hydrolysis of the neurotransmitter acetylcholine. Recent years have added a considerable amount of structural knowledge about this protein as well as opened new perspectives to the study... |
8947056 | Repercussions of DNA tracking by the type IC restriction endonuclease EcoR124I on linear, circular and catenated substrates. | Type I restriction endonucleases such as EcoR124I cleave DNA at undefined loci, distant from their recognition sequences, by a mechanism that involves the enzyme tracking along the DNA between recognition and cleavage sites. This mechanism was examined on plasmids that carried recognition sites for EcoR124I and recombi... |
8947044 | Connectivity and orientation of the seven helical bundle in the tachykinin NK-1 receptor probed by zinc site engineering. | A high affinity, tridentate metal ion site has been constructed previously by His substitutions in an antagonist binding site located between transmembrane segment (TM)-V and TM-VI in the substance P NK-1 receptor. Here, an attempt is made to probe helix-helix interactions systematically in the NK-1 receptor by enginee... |
8947032 | A tyrosine-based motif and a casein kinase II phosphorylation site regulate the intracellular trafficking of the varicella-zoster virus glycoprotein I, a protein localized in the trans-Golgi network. | We have studied the intracellular trafficking of the envelope glycoprotein I (gpI) of the varicella-zoster virus, a human herpes virus whose assembly is believed to occur in the trans-Golgi network (TGN) and/or in endocytic compartments. When expressed in HeLa cells in the absence of additional virally encoded factors,... |
8947023 | The ornithodorin-thrombin crystal structure, a key to the TAP enigma? | Ornithodorin, isolated from the blood sucking soft tick Ornithodoros moubata, is a potent (Ki = 10(-12) M) and highly selective thrombin inhibitor. Internal sequence homology indicates a two domain protein. Each domain resembles the Kunitz inhibitor basic pancreatic trypsin inhibitor (BPTI) and also the tick anticoagul... |
8943050 | A functional interleukin 12 receptor complex is composed of two beta-type cytokine receptor subunits. | We have identified a cDNA from a human phytohemagglutinin-activated lymphoblast library encoding a protein that binds 125I-labeled human interleukin 12 (125I-huIL-12) with a Kd of about 5 nM when expressed in COS-7 cells. When coexpressed in COS-7 cells with the previously identified IL-12 beta receptor (IL-12R beta) p... |
8942538 | Jack A. Barney Resident Research Award winner. The inflammatory profile of interleukin-6, interleukin-8, and soluble intercellular adhesion molecule-1 in postinjury multiple organ failure. | <h4>Background</h4>Interleukin-6 (IL-6), interleukin-8 (IL-8), and adhesion molecules have been implicated as mediators in neutrophil (PMN) and endothelial cell (EC) interactions leading to postinjury multiple organ failure (MOF). Our hypothesis was that circulating levels of IL-6, IL-8, and soluble intercellular adhes... |
8941648 | Immune response to type III group B streptococcal polysaccharide-tetanus toxoid conjugate vaccine. | Group B Streptococcus (GBS) is an important perinatal pathogen. Because transplacentally acquired maternal antibodies to the GBS capsular polysaccharides (CPS) confer protection, prevention of infant disease may be possible after immunization of women. Unfortunately, the purified CPS of GBS are only variably immunogeni... |
8941396 | Solution of the conformation and alignment tensors for the binding of trimethoprim and its analogs to dihydrofolate reductase: 3D-quantitative structure-activity relationship study using molecular shape analysis, 3-way partial least-squares regression, and 3-way factor analysis. | Molecular recognition is the basis of rational drug design, and for this reason it has been extensively studied. However, the process by which a ligand recognizes and binds to its receptor is complex and not well understood. For the case in which the geometries (conformation and alignment) of the ligand and receptor ar... |
8939367 | A karyotypic analysis of the lesser Malay chevrotain, Tragulus javanicus (Artiodactyla: Tragulidae). | Chevrotains are small forest-dwelling ruminants of the family Tragulidae. The chromosome number of the lesser Malay chevrotain was determined to be 2n = 32, NF = 64, G- and Q-banding allowed the identification of homologous chromosomes, and C-banding demonstrated the presence of pericentromeric, telomeric and interstit... |
8939366 | On the importance of DNA strand breaks as the first event to initiate sister chromatid exchange (SCE): experiments with restriction endonuclease BglI. | The exact molecular mechanism of sister chromatid exchange (SCE) is still unknown, despite the many reports dealing with this cytogenetic end point published in the last 40 years. One point to be investigated is the nature of the original lesion(s) in DNA leading to the production of SCE. Whereas, for chromosomal aberr... |
8939365 | Construction of chromosome-specific DNA libraries covering the whole genome of field bean (Vicia faba L.). | Recombinant DNA libraries were constructed for seven chromosome types isolated from two translocation lines of field bean (Vicia faba L.) with reconstructed karyotypes. The chromosomes were selected so that the set of libraries covers the whole V. faba genome more than once. Individual chromosome types were highly puri... |
8939364 | The chromosome complement of Acomys spp. (Rodentia, Muridae) from Oursi, Burkina Faso--the ancestral karyotype of the cahirinus-dimidiatus group? | We present here data on chromosome banding analysis (R- and C-bands) of Acomys sp. (Rodentia, Muridae) from Oursi, Burkina Faso, characterized by 2n = FN = 68 and comparison of its banding patterns with those of Acomys dimidiatus from Saudi Arabia (2n = 38, FN = 70), studied previously. The study revealed complete homo... |
8939363 | Molecular diversification of tandemly organized DNA sequences and heterochromatic chromosome regions in some Triticeae species. | The subtelomeric heterochromatin of rye (Secale cereale) chromosomes makes up 12-18% of the genome and consists largely of a small number of tandemly organized DNA sequence families. The genomic organization, chromosomal locations and the structural organization of monomer units of the major DNA sequences from these re... |
8939362 | A light microscopic atlas of meiosis in Arabidopsis thaliana. | An atlas of meiosis in Arabidopsis thaliana, encompassing all stages from preleptotene to telophase II and early microspore formation, is presented in detail for the first time. The photomicrographs and descriptions are based on staining with the DNA fluorochrome 4',6-diamidino-2-phenylindole (DAPI) combined with a spr... |
8939361 | Molecular features of the TSPY gene of gibbons and Old World monkeys. | Restriction pattern, chromosome localization and the sequence of the testis-specific gene, TSPY, were investigated in the white-handed gibbon, agile gibbon, siamang, hamadryas baboon and Japanese monkey. Southern blot analysis showed the TSPY gene to be male specific in the primates used and disclosed variability of re... |
8939360 | Physical mapping of repetitive DNA sequences and 5S and 18S-26S rDNA in five wild species of the genus Hordeum. | The genetic relationships between several wild species and subspecies of the genus Hordeum were assessed using fluorescence in situ hybridization (FISH). Plant material included natural populations of wild barley growing in Spain of the annual species, H. marinum ssp. marinum (2n = 14) and gussoneanum (2n = 14), and H.... |
8939359 | Comparison of ribosomal DNA sites in Lolium species by fluorescence in situ hybridization. | The position of the 18S-5.8S-26S and 5S rRNA genes have been physically mapped on the chromosomes of seven Lolium taxa. 18S-5.8S-26S sites were seen on two pairs of chromosomes in the inbreeding taxa. In the outbreeding taxa six sites were found in the L. multiflorum, seven in L. perenne and nine in L. rigidum var. rig... |
8937468 | Modulation of oligonucleotide-induced immune stimulation by cyclodextrin analogs. | Some phosphorothioate oligonucleotides have been shown previously to stimulate cell proliferation and immunoglobulin production. In the current study, we examined the effects of cyclodextrin analogs as immunomodulatory agents for oligonucleotide-induced immune stimulation, both in vitro and in vivo. Incubation of splen... |
8934226 | Characterization of vectors for gene therapy formed by self-assembly of DNA with synthetic block co-polymers. | Cationic polymers can self-assemble with DNA to form polyelectrolyte complexes capable of gene delivery, although biocompatibility of the complexes is generally limited. Here we have used A-B type cationic-hydrophilic block co-polymers to introduce a protective surface hydrophilic shielding following oriented self-asse... |
8933425 | Multivariate analysis of capillary electrophoresis separation conditions for Z-E isomers of clomiphene. | Plackett-Burman (P-B) experimental design has been used to optimize the factors affecting separation of Z and E isomers of clomiphene (zuclomiphene and enclomiphene respectively) using capillary electrophoresis. The P-B design was used to simultaneously investigate the following five factors: buffer ionic strength, buf... |
8933351 | pH-dependent microspheres from modified soybean protein hydrolysate. | Soybean hydrolysate is a hydrophilic mixture of amino acids and low molecular peptides which are soluble over the whole pH range. Chemical modification of soybean hydrolysate with aromatic acyl chlorides resulted in a product that yielded pH-dependent microspheres. Investigation into the physiochemical properties of th... |
8932368 | Effects on NaeI-DNA recognition of the leucine to lysine substitution that transforms restriction endonuclease NaeI to a topoisomerase: a model for restriction endonuclease evolution. | Substituting lysine for leucine at position 43 (L43K) transforms NaeI from restriction endonuclease to topoisomerase and makes NaeI hypersensitive to intercalative anticancer drugs. Here we investigated DNA recognition by Nael-L43K. Using DNA competition and gel retardation assays, NaeI-L43K showed reduced affinity for... |
8931151 | A novel organic solvent-based coupling method for the preparation of covalently immobilized proteins on gold. | A novel organic solvent-based coupling method has been developed for the covalent immobilization of biological material to gold surfaces. The method employs the polar organic solvent anhydrous 2,2,2-trifluoroethanol as the reaction medium and involves dissolution of the protein (catalase) in the solvent allowing protei... |
8931147 | Secondary structure, membrane localization, and coassembly within phospholipid membranes of synthetic segments derived from the N- and C-termini regions of the ROMK1 K+ channel. | The hydropathy plot of the inwardly rectifying ROMK1 K+ channel, which reveals two transmembrane and a pore region domains, also reveals areas of intermediate hydrophobicity in the N terminus (M0) and in the C terminus (post-M2). Peptides that correspond to M0, post-M2, and a control peptide, pre-M0, were synthesized a... |
8931137 | Cloning, expression, and spectroscopic characterization of Cucumis sativus stellacyanin in its nonglycosylated form. | The cDNA encoding the 182 amino acid long precursor stellacyanin from Cucumis sativus was isolated and characterized. The protein precursor consists of four sequence domains: I, a 23 amino acid hydrophobic N-terminal signal peptide with features characteristic of secretory proteins; II, a 109 amino acid copper-binding ... |
8929279 | Study of supramolecular structures released from the cell wall of Candida albicans by ethylenediamine treatment. | Candida albicans cell wall components were analyzed by ethylenediamine (EDA) treatment. Based on their different solubility properties, the cell wall components produced three fractions (A, B, and C). Fractions B (EDA-soluble, water-insoluble) and C (EDA-insoluble) contained glucan, chitin, and protein in different pro... |
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