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7492319 | Analysis of transcripts encoding novel members of the mammalian metalloprotease-like, disintegrin-like, cysteine-rich (MDC) protein family and their expression in reproductive and non-reproductive monkey tissues. | A number of sequence-related, cysteine-rich proteins containing metalloprotease-like and disintegrin-like domains (the MDC protein family), at least one of which has been shown to play a role in egg recognition during fertilization, are abundantly expressed in the mammalian male reproductive tract. In this paper we rep... |
7492311 | Synthesis of a Cys949Tyr alpha 2-macroglobulin thiol ester mutant: co-transfection with wild-type alpha 2-macroglobulin in an episomal expression system. | A full-length alpha 2-macroglobulin (alpha 2M) cDNA was cloned into the episomal expression vectors pREP7 and pMEP4. Electroporation of the cell lines WI-L2-729HF2, U-937, K-562 and an Epstein-Barr virus-transformed cell line resulted in stable transfectants only with K-562 cells. Stable expression was obtained exclusi... |
7473751 | An integrated kinetic analysis of intermediates and transition states in protein folding reactions. | Relaxation rates for folding and unfolding of two proteins have been measured over a range of denaturant concentrations to examine the reaction pathways leading to the late transition state. The proteins were chosen for their marked differences in both kinetic and structural properties. Results for the N-terminal domai... |
7490299 | Myosin II filament assemblies in the active lamella of fibroblasts: their morphogenesis and role in the formation of actin filament bundles. | The morphogenesis of myosin II structures in active lamella undergoing net protrusion was analyzed by correlative fluorescence and electron microscopy. In rat embryo fibroblasts (REF 52) microinjected with tetramethylrhodamine-myosin II, nascent myosin spots formed close to the active edge during periods of retraction ... |
7479962 | Identification of residues linked to the slow-->fast transition of thrombin. | Residues energetically linked to the allosteric transition of thrombin from its anticoagulant slow form to the procoagulant fast form have been identified by site-directed mutagenesis. The energetics of recognition by the two forms of the enzyme were probed by using a synthetic chromogenic substrate, fibrinogen, and hi... |
7578141 | CP-MAS 13C-NMR dipolar correlation spectroscopy of 13C-enriched chlorosomes and isolated bacteriochlorophyll c aggregates of Chlorobium tepidum: the self-organization of pigments is the main structural feature of chlorosomes. | Magic angle spinning (MAS) NMR dipolar correlation spectroscopy was applied for the first time to a biologically intact system, the light-harvesting chlorosomes of the green photosynthetic bacterium Chlorobium tepidum. The MAS spectra provide evidence that the self-organization of many thousands of bacteriochlorophyll ... |
7583674 | A short linear peptide derived from the N-terminal sequence of ubiquitin folds into a water-stable non-native beta-hairpin. | A 16-residue peptide derived from the N-terminal sequence of ubiquitin forms a stable monomeric beta-hairpin that is estimated to be approximately 80% populated in aqueous solution. The peptide sequence has been modified from native ubiquitin by replacing the five residues found in a type I G1 bulged turn (Thr-Leu-Thr-... |
7477342 | Femtosecond molecular dynamics of tautomerization in model base pairs. | Hydrogen bonds commonly lend robustness and directionality to molecular recognition processes and supramolecular structures. In particular, the two or three hydrogen bonds in Watson-Crick base pairs bind the double-stranded DNA helix and determine the complementarity of the pairing. Watson and Crick pointed out, howeve... |
7473600 | Topographical modification of melanotropin peptide analogues with beta-methyltryptophan isomers at position 9 leads to differential potencies and prolonged biological activities. | We have introduced topographical constraints at the 9 position of a superpotent cyclic alpha-melanotropin analogue, Ac-Nle4-Asp5-His6-DPhe7-Arg8-Trp9-Lys10-NH2, by incorporating a methyl group at the beta-carbon of Trp9. These studies were performed on the Trp side chain pharmacophore to identify the bioactive topograp... |
7479847 | Location of the active site of allosteric chorismate mutase from Saccharomyces cerevisiae, and comments on the catalytic and regulatory mechanisms. | The active site of the allosteric chorismate mutase (chorismate pyruvatemutase, EC 5.4.99.5) from yeast Saccharomyces cerevisiae (YCM) was located by comparison with the mutase domain (ECM) of chorismate mutase/prephenate dehydratase [prephenate hydro-lyase (decarboxylating), EC 4.2.1.51] (the P protein) from Escherich... |
7487918 | Factors affecting the stereospecificity and catalytic efficiency of the tryptophan synthase-catalysed exchange of the pro-2R and pro-2S protons of glycine. | 13C-NMR has been used to follow the tryptophan synthase (EC 4.2.1.20)-catalysed hydrogen-deuterium exchange of the pro-2R and pro-2S protons of [2-13C]glycine. The first- and second-order rate constants for exchange when the alpha 2 beta 2 enzyme complex is or is not saturated with glycine have been determined at pH 7.... |
7487948 | Identification of direct-repeat-binding protein 1 (DRP-1), a DNA-binding protein that binds specifically to the 'malic' enzyme gene promoter direct repeat element. | The 'malic' enzyme (ME) gene promoter contains three main regulatory regions. One of these, the direct repeat element (DRE), contains tandem degenerate Sp1-binding sites separated by a 3 bp intervening sequence. We now show that a previously unreported 95 kDa protein, which we have designated DRP-1, binds strongly to t... |
7485397 | Neurofibromatosis type 2 protein co-localizes with elements of the cytoskeleton. | The product of the neurofibromatosis type 2 (NF2) tumor suppressor gene is a 595-amino-acid protein bearing resemblance to a family of band-4.1-related proteins. These proteins, including ezrin, radixin, and moesin, probably function as molecular linking proteins, connecting the cytoskeleton to the cell membrane. On th... |
7485395 | Regulation of fibrin deposition by malignant mesothelioma. | Malignant mesothelioma (MM) is a locally aggressive tumor that spreads by poorly understood mechanisms. Because neoplastic spread has been linked to altered fibrin turnover, we used immunohistochemistry of nine MM and three fibrous tumors of the pleura to confirm in vivo fibrin deposition and expression of selected coa... |
7485389 | Distributions of melanoma growth stimulatory activity of growth-regulated gene and the interleukin-8 receptor B in human wound repair. | The alpha-chemokines have been implicated as regulators of proliferation and differentiation of normal keratinocytes and as mediators of keratinocyte maturation and migration in inflammatory processes that involve the skin. Using the cutaneous wound repair model, we examined the sites and temporal sequence of the appea... |
7592443 | Flagellar structure and hyperthermophily: analysis of a single flagellin gene and its product in Aquifex pyrophilus. | The polytrichously inserted flagella of Aquifex pyrophilus, a marine hyperthermophilic bacterium growing at 85 degrees C, were isolated and purified. Electron micrographs of the 19-nm-diameter flagellar filaments show prominent helical arrays of subunits. The primary structure of these 54-kDa flagellin monomers determi... |
7593180 | GTP hydrolysis by Ran occurs at the nuclear pore complex in an early step of protein import. | Mediated import of proteins into the nucleus involves multiple cytosolic factors, including the small GTPase Ran. Whether Ran functions by interacting with other cytosolic proteins or components of the nuclear pore complex has been unclear. Furthermore, the precise transport step where Ran acts has not been determined.... |
7592372 | Binding affinity and functional significance of NIT2 and NIT4 binding sites in the promoter of the highly regulated nit-3 gene, which encodes nitrate reductase in Neurospora crassa. | In the filamentous fungus Neurospora crassa, both the global-acting regulatory protein NIT2 and the pathway-specific regulatory protein NIT4 are required to turn on the expression of the nit-3 gene, which encodes nitrate reductase, the first enzyme in the nitrate assimilatory pathway. Three NIT2 binding sites and two N... |
8528591 | Detection of rDNA sites in sugarcane by FISH. | Hybridization sites of an rDNA probe coding for the 5.8S, 18S and 26S genes were detected on the chromosomes of sugarcane and a related genus, Erianthus, using fluorescence in situ hybridization. One unpaired and five paired hybridization sites were detected in a Saccharum spp. hybrid. A first introgression hybrid (I1)... |
8528590 | Chromosome banding and synaptonemal complexes in Leporinus lacustris (Pisces, Anostomidae): analysis of a sex system. | Leporinus lacustris had been studied previously, and shows 2n = 54 metacentric and submetacentric chromosomes, including an XX/XY system described on the basis of Giemsa-stained preparations. However, there was some doubt regarding the identification of the sex chromosomes, because of the relative homogeneity of this s... |
8528589 | Meiosis in the leek (Allium porrum L.) revisited. I. Prophase I pairing. | Meiotic chromosome pairing of the tetraploid species Allium porrum, the cultivated leek, was analysed by electron microscopy of 83 surface-spread nuclei in the late zygotene to early diplotene interval of prophase I, from four different varieties. Prophase I quadrivalent frequency, at 71%, marginally but significantly ... |
8528588 | Mitotic and meiotic detection of radiation-induced translocations in mouse stem cell spermatogonia using fluorescence in situ hybridization. | The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescence in situ hybridization analysis of mitotic or meiotic stages. Specific D... |
8528587 | Brdu replication bands in the anguilliform fish Echelus myrus. | High-resolution replication banding patterns have been obtained in prometaphase and metaphase chromosomes of the anguilliform fish species Echelus myrus by treating kidney cell cultures with 5-bromodeoxyuridine during the mid-late synthesis phase. The results show the superiority of the in vitro technique in obtaining ... |
8528586 | Stable chromosome fission associated with rDNA mobility. | A spontaneous chromosome fission in the plant Hypochoeris radicata has been characterized by Feulgen staining, in situ hybridization of the rDNA probe pTA71 and silver staining for active nucleolus organizing regions. The parental acrocentric chromosome has no detectable ribosomal genes at the centromere, but both fiss... |
8528585 | Confirmation of the copy number of chromosome 1 in interphase nuclei from paraffin sections of breast tumours by fluorescence in situ hybridization. | Fluorescence in situ hybridization (FISH) was used to establish the copy number of chromosome 1 in a set of nine breast tumours in which the chromosome had previously been shown to have undergone a variety of rearrangements by loss of heterozygosity studies. In each case, FISH with satellite III DNA from chromosome 1q1... |
8528584 | Loss of telomeric sites in the chromosomes of Mus musculus domesticus (Rodentia: Muridae) during Robertsonian rearrangements. | Mouse chromosomes possessing multiple Robertsonian rearrangements (Rb chromosomes) have been examined using fluorescence in situ hybridization with the telomeric consensus sequence (TTAGGG)n. No hybridization signals were detected at the primary constriction of Rb chromosomes. This observation leads us to conclude that... |
7591088 | Helicobacter pylori cytotoxin: importance of native conformation for induction of neutralizing antibodies. | We have attempted to express the Helicobacter pylori vacuolating cytotoxin in Escherichia coli. Although the 95-kDa VacA polypeptide was expressed abundantly, it completely lacked any biological activity. In addition, this material failed to induce neutralizing antibodies after immunization of rabbits. In contrast, hig... |
7565776 | The Saccharomyces cerevisiae HSP12 gene is activated by the high-osmolarity glycerol pathway and negatively regulated by protein kinase A. | The HSP12 gene encodes one of the two major small heat shock proteins of Saccharomyces cerevisiae. Hsp12 accumulates massively in yeast cells exposed to heat shock, osmostress, oxidative stress, and high concentrations of alcohol as well as in early-stationary-phase cells. We have cloned an extended 5'-flanking region ... |
7565767 | Transcriptional activation of the Epstein-Barr virus latency C promoter after 5-azacytidine treatment: evidence that demethylation at a single CpG site is crucial. | The Epstein-Barr Virus (EBV) latency C promoter (Cp) is the origin of transcripts for six viral proteins. The promoter is active in lymphoblastoid B-cell lines but silent in many EBV-associated tumors and tumor cell lines. In these latter cell lines, the viral episome is hypermethylated in the vicinity of this promoter... |
7565766 | Identification of a silencer module which selectively represses cyclic AMP-responsive element-dependent gene expression. | The cyclic AMP (cAMP)-inducible promoter from the rat lactate dehydrogenase A subunit gene (LDH A) is associated with a distal negative regulatory element (LDH-NRE) that represses inherent basal and cAMP-inducible promoter activity. The element is of dyad symmetry, consisting of a palindromic sequence with two half-sit... |
7565750 | YY1 facilitates the association of serum response factor with the c-fos serum response element. | YY1 is a multifunctional transcription factor that acts as an activator or repressor in different contexts. YY1 binds to multiple sites in the mouse c-fos promoter, inducing at each site a sharp DNA bend. Binding of YY1 to a site situated between the cyclic AMP response element (CRE) and the TATA box bends the DNA in a... |
31827369 | P<sub>2</sub>-Purinoceptors: Advances and therapeutic opportunities. | The recent cloning of a number of distinct receptors belonging to the P<sub>2</sub>-purinoceptor superfamily has provided conclusive evidence for a pivotal role for ATP and other nucleotides as effector molecules involved in cell-to-cell communication and the modulation of many basic aspects of tissue function. ATP its... |
22358560 | Adaptation of cholesterol-requiring NS0 mouse myeloma cells to high density growth in a fully defined protein-free and cholesterol-free culture medium. | NS0 has been used as a fusion partner for the production of hybridomas and has more recently been engineered to produce recombinant protein. A protein-free culture medium, designated W38 medium, has previously been developed which supported high density growth of rat myeloma and hybridoma cell lines. NS0 cells failed t... |
20882118 | Very High Affinity DNA Recognition by Bicyclic and Cross-Linked Oligonucleotides. | We report the synthesis and DNA incorporation of a novel C-5 thiopropyne-substituted thymidine derivative which can be used to bring about covalent crosslinks between two noncomplementary DNA strands. This modified thymine pairs normally with adenine in duplex DNA and is shown not to be destabilizing to DNA double heli... |
18966390 | A beta-cyclodextrin based fiber-optic chemical sensor: a fractal analysis. | A fractal analysis is presented for the binding of pyrene in solution to beta-cyclodextrin attached to a fiber-optic chemical sensor. The specific (k(l)) and non-specific binding rate coefficients and the fractal dimension (D(f)) (specific binding case only) both tend to increase as the pyrene concentration in solution... |
18966375 | Determination of carbaryl as its primary metabolite, 1-naphthol, by reversed-phase high-performance liquid chromatography with fluorometric detection. | Carbaryl and its hydrolysis product, 1-naphthol, are determined simultaneously, and in a mixture of other pesticides, by reversed-phase high-performance liquid chromatography (HPLC). Fluorometric detection affords a higher degree of selectivity than absorbance detection, while providing detection limits of 1.0 ng ml(-1... |
18966362 | Extraction spectrophotometric determination of mercury(II) using thiacrown ethers and Bromocresol Green. | A reasonably sensitive and highly selective spectrophotometric method for the determination of mercury(II) is proposed. The method is based on the extraction of the ion-associate formed by a mercury(II) thiacrown ether cationic complex with Bromocresol Green as the anionic counter-ion using chloroform as the extracting... |
7560098 | Binding-, intracellular transport-, and biosynthesis-defective mutants of vasopressin type 2 receptor in patients with X-linked nephrogenic diabetes insipidus. | Nephrogenic diabetes insipidus (NDI) is most often an X-linked disorder in which urine is not concentrated due to renal resistance to arginine vasopressin. We recently identified four vasopressin type 2 receptor gene mutations in unrelated X-linked NDI families, including R143P, delta V278, R202C, and 804insG. All thes... |
7560069 | Markedly inhibited 7-dehydrocholesterol-delta 7-reductase activity in liver microsomes from Smith-Lemli-Opitz homozygotes. | We investigated the enzyme defect in late cholesterol biosynthesis in the Smith-Lemli-Opitz syndrome, a recessively inherited developmental disorder characterized by facial dysmorphism, mental retardation, and multiple organ congenital anomalies. Reduced plasma and tissue cholesterol with increased 7-dehydrocholesterol... |
7592323 | Anaerobic protoporphyrin biosynthesis does not require incorporation of methyl groups from methionine. | It was recently reported (H. Akutsu, J.-S. Park, and S. Sano, J. Am. Chem. Soc. 115:12185-12186, 1993) that in the strict anaerobe Desulfovibrio vulgaris methyl groups from exogenous L-methionine are incorporated specifically into the 1 and 3 positions (Fischer numbering system) on the heme groups of cytochrome c3. It ... |
7558334 | Iron-repressible outer membrane proteins of Helicobacter pylori involved in heme uptake. | Helicobacter pylori is known to be a causative agent of gastritis and peptic ulcer disease in humans. The acquisition of iron from the human host may contribute greatly to the virulence of this organism. To study this, H. pylori was cultured under iron-restrictive conditions to induce synthesis of possible iron-regulat... |
7558322 | Candida albicans cell walls contain the fluorescent cross-linking amino acid dityrosine. | Several clinical and laboratory isolates of Candida albicans have a natural blue surface fluorescence when cultured and observed with sensitive optics. The localization and color of the fluorescence are similar to those of the natural fluorescence of sporulated Saccharomyces cerevisiae which is caused by the generation... |
7558300 | Pertussis toxin export genes are regulated by the ptx promoter and may be required for efficient translation of ptx mRNA in Bordetella pertussis. | The gene products from an 8-kb region adjacent to the 3' end of the ptx operon are required by Bordetella pertussis for the export of pertussis holotoxin. At least one of these gene products (PtlC) is specifically required for the export of assembled holotoxin from the periplasmic space. ptlC mutants exhibit a 20-fold ... |
7558725 | Effects of growth factors on proliferation and differentiation in human lens epithelial cells in early subculture. | <h4>Purpose</h4>A successful method to subculture human lens epithelial (HLE) cells that retain their intrinsic characteristics is of great importance. This study examines the effects of four different growth factors on proliferation and differentiation in HLE cells in early subcultures.<h4>Methods</h4>Specimens of HLE... |
7575480 | A novel lipid-binding protein from the cestode Moniezia expansa. | A lipid-binding protein (LBP) has been purified from the cytosol of the cestode Moniezia expansa. The native LBP was found to be an oligomer of approx. 250 kDa, consisting of 11 kDa monomers. The LBP bound saturated and unsaturated fatty acids, but not their CoA derivatives, with KD values in the range 0.68-7.8 microM.... |
7568238 | Enhanced conformational sampling in Monte Carlo simulations of proteins: application to a constrained peptide. | A Monte Carlo simulation method for globular proteins, called extended-scaled-collective-variable (ESCV) Monte Carlo, is proposed. This method combines two Monte Carlo algorithms known as entropy-sampling and scaled-collective-variable algorithms. Entropy-sampling Monte Carlo is able to sample a large configurational s... |
7568210 | Ligand-directed retroviral targeting of human breast cancer cells. | We explored the feasibility of designing retroviral vectors that can target human breast cancer cells with characteristic receptors via ligand-receptor interaction. The ecotropic Moloney murine leukemia virus envelope was modified by insertion of sequences encoding human heregulin. Ecotropic virus, which normally does ... |
7666560 | Modest truncation of the major capsid protein abrogates B19 parvovirus capsid formation. | In vitro studies have suggested an important role for the minor capsid protein (VP1) unique region and the junction between VP1 and the major capsid protein (VP2) in the neutralizing immune response to B19 parvovirus. We investigated the role of the NH2-terminal region of the major structural protein in capsid structur... |
7666550 | Self-assembly in vitro of purified CA-NC proteins from Rous sarcoma virus and human immunodeficiency virus type 1. | The internal structural proteins of retroviruses are proteolytically processed from the Gag polyprotein, which alone is able to assemble into virus-like particles when expressed in cells. All Gag proteins contain domains corresponding to the three structural proteins MA, CA, and NC. We have expressed the CA and NC doma... |
7545244 | Structural modulations of the envelope gp120 glycoprotein of human immunodeficiency virus type 1 upon oligomerization and differential V3 loop epitope exposure of isolates displaying distinct tropism upon virion-soluble receptor binding. | We investigated the binding of conformation-dependent anti-V2, anti-V3, and anti-CD4-binding site monoclonal antibodies to monomeric and virion-associated gp120 from human immunodeficiency virus type 1 isolates displaying marked differences in cell tropism. For all viruses examined, we found that the half-maximal bindi... |
7666507 | Functional interaction between the human cytomegalovirus 86-kilodalton IE2 protein and the cellular transcription factor CREB. | The 86-kDa IE2 protein (IE86) of human cytomegalovirus (HCMV) has been described as a promiscuous transactivator of viral, as well as cellular, gene expression. Investigation of the mechanism used by IE86 to activate gene expression from the early UL112/113 promoter of HCMV revealed the existence of three binding sites... |
9495116 | Antibacterial activity of ciprofloxacin-beta-cyclodextrin complex and its efficacy in dental implants. | Ciprofloxacin forms an inclusion complex with beta-cyclodextrin. The in vitro antibacterial activity of ciprofloxacin on E. coli and Staphylococcus aureus was found better on complexation. The complex was found very effective as a local antibacterial agent when used in dental implants. Significant reduction in the ging... |
9383472 | Use of semi-synthetic transfer RNAs to probe molecular recognition by Escherichia coli proline-tRNA synthetase. | <h4>Background</h4>The attachment of specific amino acids to the 3'-end of cognate transfer of RNAs (tRNAs) is catalyzed by a class of enzymes known as aminoacyl-tRNA synthetases (aaRS). We have previously demonstrated that Escherichia coli proline-tRNA synthetase (ProRS) can aminoacylate semi-synthetic tRNAs prepared ... |
9057810 | Cartilage morphogenesis: role of bone and cartilage morphogenetic proteins, homeobox genes and extracellular matrix. | Cartilage morphogenesis is one of the central topics in skeletal development. Cartilage geometry determines the future architecture of bones, joints and associated ligaments and tendons. Recent progress in this area has come from purification, cloning and expression of genes encoding bone and cartilage morphogenetic pr... |
8747275 | The interaction between human Fc gamma RI and the gamma-chain is mediated solely via the 21 amino acid transmembrane domain of Fc gamma RI. | We have established a biological assay to investigate the nature of the non-covalent interaction between two integral type I membrane proteins, Fc gamma RI and gamma-chain. Fc gamma RI, the human high affinity receptor for immunoglobulin G (IgG), is expressed on the surface of macrophages and monocytes and mediates a b... |
8679075 | [Technological studies of effects of inclusion on pericarpium Citri reticulatae volatile oil-beta-cyclodextrin]. | The effects of inclusion on Pericarpium Citri Reticulatae volatile oil-beta-cyclodextrin were studied by comparing four methods saturation, grinding, liquid to liquid and liquid to gas. The utilization ratio of oil, the ratio of oil in inclusion complex and the recovery of inclusion complex were used as the criteria in... |
8686902 | Predicting drug-membrane interactions by HPLC: structural requirements of chromatographic surfaces. | Drug-membrane interactions have recently been studied by immobilized artificial membrane (IAM) chromatography (Pidgeon, C.; et al. J. Med. Chem. 1995, 38, 590-595. Ong, S.; et al. Anal. Chem. 1995, 67, 755-762), and the molecular recognition properties of IAM surfaces toward drug binding/partitioning appear to be remar... |
8686900 | Capillary electrophoresis/frontal analysis for microanalysis of enantioselective protein binding of a basic drug. | A new HPCE method was developed for the enantioselective determination of the unbound concentration of a basic drug under plasma protein binding equilibrium. The racemic basic drug verapamil (VER) and human serum albumin mixed solution was used as a model sample solution. The sample solution was introduced into a fused... |
8586062 | Novel separation scheme for capillary electrophoresis of enantiomers. | A systematic approach is described for methods development of chiral separations of weak acidic and basic compounds by capillary electrophoresis, using several natural and derivatized neutral cyclodextrins as chiral selectors. Following the methods development scheme suggested here, the appropriate pH of the running bu... |
8590005 | Structure of beta 2-bungarotoxin: potassium channel binding by Kunitz modules and targeted phospholipase action. | <h4>Background</h4>beta-bungarotoxin is a heterodimeric neurotoxin consisting of a phospholipase subunit linked by a disulfide bond to a K+ channel binding subunit which is a member of the Kunitz protease inhibitor superfamily. Toxicity, characterized by blockage of neural transmission, is achieved by the lipolytic act... |
8581388 | Bispecific antibodies as targeting agents for boron neutron capture therapy of brain tumors. | Boron neutron capture therapy (BNCT) is based on the nuclear reaction that occurs when boron-10, a stable isotope, is irradiated with low energy (< or = 0.025 eV) or thermal neutrons to yield alpha particles and recoiling lithium-7 nuclei. A major requirement for the success of BNCT is the selective delivery of a suffi... |
8595393 | Structural and functional features of noxiustoxin: a K+ channel blocker. | Binding of [125I]-Noxiustoxin to rat brain synaptosome membranes and displacement with synthetic peptides corresponding to the amino acid sequence of Noxiustoxin, show that the N-terminal segment of this toxin is implicated in the recognition of brain K(+)-channels. Cleavage of NTX with cyanogen bromide, endopeptidase ... |
8595258 | Enzymic synthesis of lacto-N-triose II and its positional analogues. | N-acetylhexosaminidase from Nocardia orientalis catalysed the synthesis of lacto-N-triose II glycoside (beta-D-GlcNAc-(1-3)-beta-D-Gal-(1-4)-beta-D-Glc-OMe, 3) with its isomers beta-D-GlcNAc-(1-6)-beta-D-Gal-(1-4)-beta-d-Glc-OMe (4) and beta-D-Gal-(1-4)-[beta-D-GlcNAc-(1-6)]-beta-D-Glc-OMe (5) through N-acetylglucosami... |
8554935 | An in vitro technique for the rapid determination of drug entry into breast milk. | 1. A simple in vitro technique that predicts drug transfer into breast milk is described. 2. Drugs of differing physical and chemical characteristics were tested. 3. The technique provides an experimental system for studying plasma to milk transfer with changing milk composition. 4. A mechanism proposing a role of milk... |
8564399 | Comparative molecular field analysis of selective A3 adenosine receptor agonists. | A series of 48 N6-benzyladenosine 5'-uronamide derivatives has been described recently as moderately selective A3 adenosine receptor agonists of nanomolar potency (Gallo-Rodriguez, C. et al. J. Med. Chem. 1994, 37, 636). Quantitative structure activity relationships in this series, including some novel derivatives, hav... |
8535243 | Destabilizing loop swaps in the CDRs of an immunoglobulin VL domain. | It is generally believed that loop regions in globular proteins, and particularly hypervariable loops in immunoglobulins, can accommodate a wide variety of sequence changes without jeopardizing protein structure or stability. We show here, however, that novel sequences introduced within complementarity determining regi... |
8801338 | Pharmaceutical and physical properties of paclitaxel (Taxol) complexes with cyclodextrins. | Paclitaxel (as Taxol) is under clinical investigation for treatment of a variety of cancers. Because of its low aqueous solubility, paclitaxel is administered in polyethoxylated castor oil (Cremophor EL) and ethanol, a vehicle associated with severe hypersensitivity reactions. Cyclodextrins (CyDs) are molecular complex... |
8801327 | Preparation, characterization, and anesthetic properties of 2-hydroxypropyl-beta-cyclodextrin complexes of pregnanolone and pregnenolone in rat and mouse. | Prototype formulations of the progesterone derivatives pregnanolone and pregnenolone were prepared by solubilizing the steroids in 2-hydroxypropyl-beta-cyclodextrin (HP beta CD). The aqueous solubility of the steroids was increased as a function of HP beta CD concentration generating linear (AL) or curvilinear (AP) pha... |
8664542 | Control of mating and development in Ustilago maydis. | In the fungus Ustilago maydis, the ability to distinguish between partners that are of the same or of different mating type is controlled by two mating-type loci. One locus allows extracellular recognition though a pheromone-based system. After cell fusion, the other mating-type locus, which exists in multiple alleles,... |
8640332 | Deoxyribose analogues of N6-cyclopentyladenosine (CPA): partial agonists at the adenosine A1 receptor in vivo. | 1. The purpose of the present study was to quantify the cardiovascular effects of the 2'-, 3'-, 5'-deoxyribose analogues of the selective adenosine A1 receptor agonist, N6-cyclopentyladenosine (CPA) in vivo. The blood concentration-effect relationships of the compounds were assessed in individual rats and correlated to... |
8573350 | A hierarchy of ECM-mediated signalling regulates tissue-specific gene expression. | A dynamic and reciprocal flow of information between cells and the extracellular matrix contributes significantly to the regulation of form and function in developing systems. Signals generated by the extracellular matrix do not act in isolation. Instead, they are processed within the context of global signalling hiera... |
8569108 | Development of chloride channel modulators. | Chloride channels are ubiquitously distributed, biophysically varied and functionally diverse. Despite the known contribution of chloride channels to the physiology of various cell types and the pathology of several diseases, high affinity ligands are not available to study these channels. Here we report the iterative ... |
8558365 | In vivo damage to chorioallantoic membrane blood vessels by porphycene-induced photodynamic therapy. | Photodynamic therapy (PDT) was performed in the chick embryo chorioallantoic membrane (CAM) for the purpose of quantitative evaluation of several porphycenes as potential photosensitizers. Porphycenes are structural isomers of porphine possessing lower symmetry of the macrocycle and are characterized by 10-fold higher ... |
8534805 | Double-stranded DNA organization in bacteriophage heads: an alternative toroid-based model. | Studies of the organization of double-stranded DNA within bacteriophage heads during the past four decades have produced a wealth of data. However, despite the presentation of numerous models, the true organization of DNA within phage heads remains unresolved. The observations of toroidal DNA structures in electron mic... |
8534797 | Voltage sensing by fluorescence resonance energy transfer in single cells. | A new mechanism has been developed for achieving fast ratiometric voltage-sensitive fluorescence changes in single cells using fluorescence resonance energy transfer. The mechanism is based on hydrophobic fluorescent anions that rapidly redistribute from one face of the plasma membrane to the other according to the Ner... |
8534795 | Equilibration and exchange of fluorescently labeled molecules in skinned skeletal muscle fibers visualized by confocal microscopy. | Confocal laser fluorescence microscopy was used to study in real time under nearly physiological conditions the equilibration and exchange characteristics of several different fluorescently labeled molecules into chemically skinned, unfixed skeletal muscle fibers of rabbit psoas. The time required for equilibration was... |
8530280 | A piroxicam derivative partly effective in chronic paroxysmal hemicrania and hemicrania continua. | Piroxicam beta-cyclodextrin has recently been observed to be equal to, or even possibly to be superior to, indomethacin (mainly with regard to side effects) in a single case of hemicrania continue. Piroxicam beta-cyclodextrin, 20 to 40 mg per day, was, accordingly, tried in six patients with chronic paroxysmal hemicran... |
8536336 | Binding specificity of mutagenic tryptophan pyrolysates for DNA conformation: spectroscopic and viscometric studies. | The compounds, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), are major potent mutacarcinogens isolated from tryptophan pyrolysate. In order to investigate their interaction with DNA and effects on DNA conformation, studies involving circular dichroism, fluo... |
8542602 | A self-included cyclomaltoheptaose derivative studied by NMR spectroscopy and molecular modelling. | The 3D structure of 6-deoxy-6-L-tyrosinylamidocyclomaltoheptaose, a self-complexing beta-cyclodextrin derivative, was determined by NMR and molecular modelling. The aminoacyl side-chain is included in the cavity and induces chemical-shift variations in the CD proton signals, allowing their complete assignment. Dipolar ... |
7489366 | Identification of a novel dual angiotensin II/vasopressin receptor on the basis of molecular recognition theory. | The molecular recognition theory suggests that binding sites of interacting proteins, for example, peptide hormone and its receptor binding site, were originally encoded by and evolved from complementary strands of genomic DNA. To test this theory, we screened a rat kidney complementary DNA library twice: first with th... |
7487335 | Cyclodextrins for growth of Helicobacter pylori and production of vacuolating cytotoxin. | Growth of Helicobacter pylori in liquid culture requires the addition of media supplements that often interfere with subsequent purification of bacterial antigens. In order to determine whether cyclodextrins can substitute for conventional H. pylori growth supplements, we cultured H. pylori in the presence of five comm... |
8534976 | Inhibition of dextran and mutan synthesis by cycloisomaltooligosaccharides. | Novel cyclic isomaltooligosaccharides, cyclodextran, strongly inhibited the dextransucrase reaction. The inhibition was dependent on the cyclodextran concentration and greatly enhanced by the first incubation at 30 degrees for 30 min. Cyclodextran-heptaose and -octaose were competitive inhibitors for sucrose yielding K... |
7588809 | Studies of the bound conformations of methyl alpha-lactoside and methyl beta-allolactoside to ricin B chain using transferred NOE experiments in the laboratory and rotating frames, assisted by molecular mechanics and dynamics calculations. | The conformation in solution of methyl beta-galactopyranosyl-(1-->4)-alpha-glucopyranoside (methyl alpha-lactoside) and methyl beta-galactopyranosyl-(1-->6)-beta-glucopyranoside (methyl beta-allolactoside) has been studied through NMR spectroscopy and molecular mechanics calculations. NOE measurements both in the labor... |
7588803 | 1H and 15N assignments and secondary structure of the starch-binding domain of glucoamylase from Aspergillus niger. | 1H and 15N NMR resonance assignments of the granular starch-binding domain (SBD) of glucoamylase from Aspergillus niger have been made by multi-dimensional homonuclear and heteronuclear NMR techniques. Secondary structure analysis based on chemical shifts, 1H-1H NOEs, coupling constants and backbone amide exchange data... |
7588802 | Expression in Aspergillus niger of the starch-binding domain of glucoamylase. Comparison with the proteolytically produced starch-binding domain. | Glucoamylase 1 from Aspergillus niger is an economically important enzyme in many industrial processes. It hydrolyses granular starch and comprises two distinct domains, a catalytic and a starch-binding domain (SBD). We have transformed A. niger with an expression vector for the secretion of SBD for physico-chemical st... |
7588641 | Catalytic residues of gamma delta resolvase act in cis. | The resolvase protein of the gamma delta transposon is a site-specific recombinase that acts by a concerted break-and-join mechanism. To analyse the role of individual resolvase subunits in DNA strand cleavage, we have directed the binding of catalytic mutants to specific recombination crossover sites or half-sites. Ou... |
7589545 | Divergent sequence motifs correlated with the substrate specificity of (methyl)malonyl-CoA:acyl carrier protein transacylase domains in modular polyketide synthases. | The amino acid sequences of a large number of polyketide synthase domains that catalyse the transacylation of either methylmalonyl-CoA or malonyl-CoA onto acyl carrier protein (ACP) have been compared. Regions were identified in which the acyltransferase sequences diverged according to whether they were specific for ma... |
7594827 | [Clinical evaluation of patients with cardiopulmonary bypass by plasma granulocyte elastase]. | To evaluate the role of granulocyte elastase (GEL) at cardiopulmonary bypass (CPB), the plasma GEL level was measured in 24 patients who underwent elective cardiac surgery and 47 patients who underwent elective gastroenterological surgery. The cardiac surgical patients were divided into two groups: 5 patients with CPB ... |
7592005 | Tendon response to tensile stress: an ultrastructural investigation of collagen:proteoglycan interactions in stressed tendon. | Tendons are parallel arrays of collagenous fibres which are specialised to resist and transmit tensile stresses. The response of tendon fibres to tensile stress is age-dependent and complex. Elastic elongation at low stress is accompanied by the disappearance of alternate light and dark bands seen in transmitted polari... |
7591990 | Extracellular matrix, supramolecular organisation and shape. | Connective tissue function is defined as the formation and maintenance of shape, without which centralised physiologies (circulatory, digestive or nervous) could not have evolved. Two elements, inextensible (collagenous) fibrils and compression-resistant interfibrillar soluble polymers (proteoglycans), cope with all us... |
7577972 | Expression of the human oxytocin receptor in baculovirus-infected insect cells: high-affinity binding is induced by a cholesterol-cyclodextrin complex. | We have expressed a c-myc epitope-tagged human oxytocin receptor in the baculovirus/Sf9 cell system. The receptor was identified by SDS-PAGE and subsequent immunoblot as a approximately 50 kDa protein which decreased to about 44 kDa upon treatment with tunicamycin. Binding studies showed that the human oxytocin recepto... |
7577971 | Alteration of the myometrial plasma membrane cholesterol content with beta-cyclodextrin modulates the binding affinity of the oxytocin receptor. | To investigate the effect of cholesterol on the oxytocin receptor function in myometrial membranes, we developed a new method to alter the membrane cholesterol content. Using a methyl-substituted beta-cyclodextrin, we were able to selectively deplete the myometrial plasma membrane of cholesterol. Vice versa, incubating... |
7589269 | A serosurvey of water-borne pathogens amongst canoeists in South Africa. | Certain health risks have been associated with recreational exposure to faecally polluted water. Canoeing in certain South African waters is considered to be a high risk activity with regard to schistosomiasis, gastroenteritis and possibly hepatitis. In a cross-sectional study, a serosurvey was conducted amongst canoei... |
7479047 | Synthesis and biological activities of a phosphorodithioate analog of 2',5'-oligoadenylate. | To enhance the resistance of 2-5A (pppA2'p5'A2'p5'A) to degradation by exo- and endonucleases, a phosphorodithioate analog was synthesized using a solid-phase phosphite triester approach with N6-benzoyl-5'-O-dimethoxytrityl-3'-O-t-butyldimethylsilyladenosine 2'-[S-(beta-thiobenzoylethyl)-pyrrolidinophosphorothioamidit ... |
7479036 | Effects of site-specific substitution of 5-fluorouridine on the stabilities of duplex DNA and RNA. | The effects of 5-fluorouridine (FUrd) and 5-fluorodeoxyuridine (FdUrd) substitution on the stabilities of duplex RNA and DNA have been studied to determine how FUrd substitution in nucleic acids may alter the efficiency of biochemical processes that require complementary base pairing for molecular recognition. The pare... |
7547996 | Identification of acetylcholine receptor channel-lining residues in the M1 segment of the alpha-subunit. | The muscle-type acetylcholine (ACh) receptor has the composition alpha 2 beta gamma delta. The subunits are arranged quasisymmetrically around a central, ion-conducting, water-filled channel. Each subunit has four membrane-spanning segments, M1-M4, and the channel through the membrane is formed among these segments. Su... |
7479790 | Cyclic polyamides for recognition in the minor groove of DNA. | Small molecules that specifically bind with high affinity to any designated DNA sequence in the human genome would be useful tools in molecular biology and potentially in human medicine. Simple rules have been developed to rationally alter the sequence specificity of minor groove-binding polyamides containing N-methyli... |
7479758 | Crystal structure of the cell cycle-regulatory protein suc1 reveals a beta-hinge conformational switch. | The Schizosaccharomyces pombe cell cycle-regulatory protein suc1, named as the suppressor of cdc2 temperature-sensitive mutations, is essential for cell cycle progression. To understand suc1 structure-function relationships and to help resolve conflicting interpretations of suc1 function based on genetic studies of suc... |
7487888 | The mRNAs for the three chains of human collagen type XI are widely distributed but not necessarily co-expressed: implications for homotrimeric, heterotrimeric and heterotypic collagen molecules. | In cartilage collagen type XI exists as heterotrimeric molecules composed of alpha 1(XI), alpha 2(XI) and alpha 3(XI) subunits. Messenger RNAs for some of the alpha chains of collagen type XI have also been found in non-chondrogenic tissues but the chain composition of the molecule in these sites is not known. Some non... |
7487876 | Protochlorophyllide reductase in photosynthetic prokaryotes and its role in chlorophyll synthesis. | 1. DNA sequences hybridizing with the wheat protochlorophyllide reductase gene have been detected during genomic Southern blots of various cyanobacterial DNA samples. No such hybridization was observed with DNA from photosynthetic bacteria. 2. A fragment amplified from Phormidium laminosum DNA has been characterized an... |
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