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9174931 | A non-radioactive assay system for screening for inhibitors of RNA-dependent reverse transcriptase activity; an analysis using aurintricarboxylic acid and plant flavonoids. | Ongoing and extensive screening for potentially selective and potent inhibitors of RNA-dependent DNA polymerases (reverse transcriptases) is important for the discovery of therapeutic agents active against retroviruses. Traditional systems for assaying the activity of reverse transcriptase enzymes have relied upon the ... |
9174930 | Immobilized metal-ion affinity chromatography: imidazole proton pump and chromatographic sequelae. II. Chromatographic sequelae. | Isocratic elution with imidazole of some protein models from a chelating gel, CSFF-IDA-M(II), resulted in their desorption owing to the low pH(6-->4) of the mobile, phase rather than to the imidazole itself (imidazole-generated fall in pH; proton pump). Gradient elution with imidazole was best accomplished when the che... |
9174929 | Structural characterization and 5'-mononucleotide binding of polyalanine beta-sheet complexes. | A study was initiated into the formation and stability of highly soluble beta-sheet macrostructures. Such beta-sheet macrostructures are useful model systems for the study of the biological function of the hydrophobic core of proteins and for the de novo design of novel catalytic mimics. In the current study, a 16-mer-... |
9174928 | Immobilization of streptavidin for immunosensors on nanostructured surfaces. | A modular immunosensor device based on silicon technology with electrochemical detection is presented. The sensor surface is functionalized with the antigen estradiol using the streptavidin-biotin system. The immobilized antigen is recognized by ferrocene-labeled antibody molecules in a competitive assay format. The fe... |
9174927 | Preliminary investigations of an amperometric oligosaccharide dehydrogenase-based electrode for the detection of glucose and some other low molecular weight saccharides. | Biosensors for the determination of sugars were constructed using oligosaccharide dehydrogenase (ODH) and soluble phenazine methosulfate (PMS) or an osmium-based three-dimensional redox hydrogel. In the latter case the enzyme and poly(1-vinylimidazole) complexed with osmium (4,4'-dimethylbpy)2Cl were cross-linked with ... |
9174926 | Development of an immunomagnetic assay system for rapid detection of bacteria and leukocytes in body fluids. | Immunomagnetic (IM) separation and concentration of specific target ligands or particles, such as bacteria or leukocytes, from complex mixtures, such as bone marrow, blood and other body fluids, is now a widely accepted technique. IM methodologies require high affinity antibodies or other receptors, but are potentially... |
9174925 | Binding of Escherichia coli LexA repressor to the RecA operator. | Equilibrium binding of Escherichia coli LexA repressor to the recA operator was studied by the polyacrylamide gel mobility shift assay as a function of solution conditions. In the presence of NaCl at 20 degrees C, there was a significant salt dependence in binding to the recA operator, typical for protein-nucleic acid ... |
9174924 | Studies on oriented and reversible immobilization of glycoprotein using novel boronate affinity gel. | The authors have previously synthesized a novel boronate affinity ligand, catechol [2-(diethylamino)carbonyl-4-bromomethyl]phenylboronate. When this ligand was coupled to cellulose beads, it bound horseradish peroxidase (HRP), a glycoprotein, at pH 7.0. In comparison, commercial m-aminophenylboronic acid-agarose did no... |
9174923 | Determination of binding constants of diabodies directed against prostate-specific antigen using electrochemiluminescence-based immunoassays. | Two diabody molecules directed against the prostate-specific antigen (PSA) were generated from a combinatorial phage display library. The C-termini of diabodies incorporated the FLAG peptide epitope (P008D diabody) or the myc epitope (P001D). Both diabodies have the same antigen-binding site. Equilibrium-binding consta... |
9174922 | Human low density lipoprotein and human serum albumin adsorption onto model surfaces studied by total internal reflection fluorescence and scanning force microscopy. | The adsorption of low density lipoprotein (LDL) and human serum albumin (HSA) to model surfaces of different hydrophobicities has been studied using two, surface-sensitive, real-time, in situ techniques: total internal reflection fluorescence (TIRF) and scanning force microscopy (SFM). The model surfaces used were: (1)... |
9174921 | Coprecipitation of proteins with matrix ligands: scaleable protein isolation. | Matrix ligands are agents for isolating proteins out of dilute crudes by coprecipitating proteins. The ligands have a strong anion sulfonate head which initiates binding to proteins having a positive net charge, ZH+ approximately 5-20. Initial binding tightens protein conformation and starts to squeeze water from confo... |
9174920 | Peptides as affinity surfaces for protein purification. | The tetrapeptide GPRP was previously shown to be an effective affinity ligand for fibrinogen when immobilized to Fractogel (Kuyas et al., 1990). The authors synthesized the GPRP peptide directly onto an aminefunctionalized POROS chromatographic resin to demonstrate the effectiveness of this approach for generating perf... |
9174919 | Alginate as a displacer for protein displacement chromatography. | Alginate use in displacement chromatography as a displacer has been studied. The experiments showed that untreated alginate is the basis of potential displacer for displacement chromatography, but needs to be cleaved into smaller chains. Alginate treated with ultrasound, which cleaves alginate into shorter polysacchari... |
9174918 | Affinity purification of biologically active and inactive forms of recombinant human protein C produced in porcine mammary gland. | Recombinant human protein C (rhPC) secreted in the milk of transgenic pigs was studied. Transgenes having different regulatory elements of the murine milk protein, whey acidic protein, were used with cDNA and genomic human protein C (hPC) DNA sequences to obtain lower and higher expressing animals. The cDNA pigs had a ... |
9174917 | Affinity of human anti-factor VIII antibodies for functional polystyrene supports. | Human anti-factor VIII antibodies (anti-FVIII) neutralize Factor VIII (FVIII) procoagulant activity. These antibodies appear in about 5-15 per cent of severely affected patients with haemophilia A treated with FVIII concentrates (Mannucci, 1993). In order to obtain non-thrombogenic materials able to interact specifical... |
9174916 | Polyvinyl alcohol-coated perfluorocarbon supports for metal chelating affinity separation of a monoclonal antibody. | The preparation, characterisation and testing of stable non-porous coated perfluorocarbon supports functionalised with the metal chelate, iminodiacetic acid (IDA) is described. Polyvinyl alcohol (PVA), a neutral hydrophilic polymer was esterified with perfluorooctanoyl chloride and anchored to the surface of solid perf... |
9174915 | Immobilized metal-ion affinity chromatography: imidazole proton pump and chromatographic sequelae. I. Proton pump. | Complexation of imidazole (Im) with an iminodiacetate (IDA) metal chelate [IDA-M(II)] ligand of chelating gel results in an acidification of the mobile phase. The scope of the action of this IDA-M(II)Im 'proton pump' in IMAC is determined by: (a) IDA-M(II) density of the gel; (b) concentration of applied Im; and (c) th... |
9174914 | Reversible and irreversible immobilization of enzymes on Graphite Fibrils. | Graphite Fibrils are hollow tubes (0.01 x 1-10 microns) consisting of concentric layers of graphite. Fibrils can be chemically modified to introduce surface functionalities such as carboxyl groups. Carboxylated fibrils were further functionalized to amino alkyl derivatives which were covalently linked to an enzyme, hor... |
9174913 | Salicylaldehyde-metal-amino acid ternary complex: a new tool for immobilized metal affinity chromatography. | An immobilized salicylaldehyde (sal) was used to build various salicylaldehyde-copper-amino acid (Sal-Cu-AA) complexes which are stable at a range of pH values (2.0-11.0). The complexes were found to bind protein molecules as IMAC resins. Thirteen proteins were examined for their binding to a Sal-Cu-Gly column. The eff... |
9174912 | Membrane microstructural templates for enzyme domain formation. | Soluble proteins can spontaneously self-organize into two-dimensional domains at membrane interfaces, given sufficient mobility and specificity to membrane-localized ligands. The authors' recent results studying interfacial domain formation of the membrane-active enzyme, phospholipase A2, indicate that lateral phase se... |
9174911 | Two lectin-like receptors for alpha 1-acid glycoprotein in mouse testis. | Three glycoforms of alpha 1-acid glycoprotein (AGP) were biotinylated to examine their binding in mouse testis by light microscopy. The transition from one stage to another in the spermatogenic cycle is marked with an appearance of a receptor for the Concanavalin A (Con A) non-reactive glycoform AGP-A in the cytoplasm ... |
9174910 | Detection of pathological changes of proteins by peptide mapping after protein digestion by use of oriented immobilized proteinases. | Diagnostic methods for detecting gastric diseases using chymotryptic digestion of pepsin are discussed. Peptide maps can be prepared using reversed-phase high-performance liquid chromatography. Batchwise chromatography by use of membranes with immobilized Tyr(I2) was used for the isolation of pepsin from gastric mucosa... |
9174909 | Affinity precipitation of proteins. | Affinity precipitation is being studied as a technique to be introduced at an early stage of downstream processing for the selective isolation of proteins. The technique utilizes a heterobifunctional ligand, which, in addition to having affinity for the target protein(s), possesses another function for controlling prec... |
9174907 | Affinity liposomes in vivo: factors influencing target accumulation. | To make universal and efficient liposome-based drug carriers, liposomes should be able to recognize and bind other targets beyond their natural targets, the cells of the reticuloendothial system. To make liposomes targeted, numerous methods to couple active substances, primarily, monoclonal antibodies, to the liposome ... |
9174906 | New formats of polymeric stationary phases for HPLC separations: molded macroporous disks and rods. | A molding process has been used for the preparation of separation media in different shapes such as rods and flat membrane-like disks. The polymerization is carried out using a mixture of monomers, porogenic solvent and free-radical initiator under conditions that afford macroporous materials with through-pores or chan... |
9174905 | Principles and applications of flow injection analysis in biosensors. | In practical applications biosensors are often forced to operate under less than optimal conditions. Because of their construction, and the physical processes and chemical reactions involved in their operation, compromise conditions are frequently required to synchronize all events taking place. Therefore, and in order... |
9021680 | Immunomodulatory peptides with high binding affinity for class II MHC molecules for the prevention of graft-versus-host disease. | Graft-versus-host disease (GVHD) represents the major barrier to successful allogeneic bone marrow transplantation. Positive and negative selection studies have unequivocally demonstrated that donor T cells are responsible for the induction phase of GVHD. Inhibition of the early steps of T cell antigen recognition lead... |
8939683 | Weak interactions and lessons from crystallization. | Ideas derived from the study of the process of crystallization may provide insights into molecular recognition in biological systems. Both processes exploit the cooperativity which arises from the formation of a large array of weak interactions. |
8987509 | Absolute configuration of octanol derivatives in apple fruits. | In extracts obtained by liquid-liquid extraction and enzymatic hydrolysis from five apple cultivars (Renao; Bedan; Peau de Chien; Noel des Champs; Red Delicious), chiral evaluation of free and glycosidically-bound octane-1,3-diol and 5(Z)-octene-1,3-diol, as well as ethyl 3-hydroxyoctanoate and ethyl 5(Z)-3-hydroxyocte... |
8973118 | A freeze-dried injectable form of ibuprofen: development and optimisation using response surface methodology. | In this study a complex of Ibuprofen and b-Hydroxypropylcyclodextrin was prepared employing a freeze drying method. The production parameters and the final specifications of this product were optimized by using response surface methodology. The results show that the freeze dried complex meets the requirements for solub... |
9027257 | [The neurochemical, molecular and ultrastructural mechanisms of the formation of latent postresuscitation encephalopathy]. | The content of total RNA and DNA, activity of Ca2+, Mg(2+)-dependent DNA endonuclease, and ultrastructural changes in nerve tissue cells were examined in the brain cortex of narcotized dogs 1 to 3 months after a 4-hour hemorrhagic shock (arterial pressure 40 mm Hg). A new variant of reconstruction of cell membranes and... |
8940689 | [Acute renal failure following surgical insult]. | It has been claimed that acute renal failure (ARF) following surgical insult was mainly due to the reduction in renal blood flow, especially in renal cortical blood flow. Recent studies, however, pointed out that the majority of the surgical ARF developed due to prolonged SIRS (systemic inflammatory response syndrome) ... |
8931984 | Noncollagenous matrix components of glomeruli in congenital nephrotic syndrome of the Finnish type: evidence of abnormal splitting of nidogen? | The congenital nephrotic syndrome of the Finnish type (CNF) is a rare autosomal recessive disease with proteinuria starting already in utero, prematurity and nephrotic syndrome developing within the first weeks of life. The basic defect of this disease is unknown but has been suggested to be restricted to the kidney gl... |
8922951 | Molecular dynamics-derived conformation and intramolecular interaction analysis of the N-acetyl-9-O-acetylneuraminic acid-containing ganglioside GD1a and NMR-based analysis of its binding to a human polyclonal immunoglobulin G fraction with selectivity for O-acetylated sialic acids. | The influence of 9-O-acetylation of GD1a, yielding GD1a (eNeu5,9Ac2) with a 9-O-acetylated sialic acid moiety linked to the outer galactose residue, on the spatial extension and mobility of the carbohydrate chain and on recognition by a natural human antibody is analysed. To study a potential impact of the O-acetyl gro... |
8917388 | beta-Sitosterol inhibits HT-29 human colon cancer cell growth and alters membrane lipids. | The purpose of the present study was to examine the effect of beta-sitosterol, the main dietary phytosterol on the growth of HT-29 cells, a human colon cancer cell line. In addition, the incorporation of this phytosterol into cellular membranes and how this might influence the lipid composition of the membranes were in... |
8910858 | Protective effect of butylated hydroxyanisole on adriamycin-induced cardiotoxicity. | Adriamycin has a wide spectrum of antitumour activity with dose-related cardiotoxicity as a major side effect. This cardiotoxicity has been suggested to result from the generation of oxygen free radicals. The objective of the present study was to investigate the influence of the antioxidant, butylated hydroxyanisole co... |
8905166 | Simultaneous determination of cholecystokinin-like immunoreactivity and dopamine release after treatment with veratrine, NMDA, scopolamine and SCH23390 in rat medial frontal cortex: a brain microdialysis study. | The release of cholecystokinin (CCK) and dopamine (DA) was measured simultaneously in the medial frontal cortex of the rat using an in vivo microdialysis technique coupled to either enzyme immunoassay or high performance liquid chromatography with electrochemical detection method. Basal levels of CCK-like immunoreactiv... |
8902613 | The crystal structure of lipase II from Rhizopus niveus at 2.2 A resolution. | The crystal and molecular structure of Lipase II from Rhizopus niveus was analyzed using X-ray single crystal diffraction data at a resolution of 2.2 A. The structure was refined to an R-factor of 0.19 for all available data. This lipase was purified and crystallized as Lipase I, which contains two polypeptide chains c... |
8891301 | Local pressure application of cannabinoid agonists increases spontaneous activity of rat substantia nigra pars reticulata neurons without affecting response to iontophoretically-applied GABA. | This study tested the hypothesis that cannabinoid agonists, applied locally into the pars reticulata of substantia nigra (SNpr), could modulate striatonigral transmission, without affecting the response of SNpr neurons to iontophoretically-applied GABA. Multibarreled glass capillary electrode assemblies were used for e... |
8890185 | IS10/Tn10 transposition efficiently accommodates diverse transposon end configurations. | Transposon Tn10 and its component insertion sequence IS10 move by non-replicative transposition. We have studied the array of reaction intermediates and products in a high efficiency in vitro IS10/Tn10 transposition reaction. Synapsis of two transposon ends, followed by cleavage and strand transfer, can occur very effi... |
8890184 | Linear diffusion of the restriction endonuclease EcoRV on DNA is essential for the in vivo function of the enzyme. | Linear diffusion along DNA is a mechanism of enhancing the association rates of proteins to their specific recognition sites on DNA. It has been demonstrated for several proteins in vitro, but to date in no case in vivo. Here we show that the restriction endonuclease EcoRV slides along the DNA, scanning approximately 1... |
8890179 | Transfer RNA structural change is a key element in the reassignment of the CUG codon in Candida albicans. | The human pathogenic yeast Candida albicans and a number of other Candida species translate the standard leucine CUG codon as serine. This is the latest addition to an increasing number of alterations to the standard genetic code which invalidate the theory that the code is frozen and universal. The unexpected finding ... |
8890176 | A direct interaction between a DNA-tracking protein and a promoter recognition protein: implications for searching DNA sequence. | Bacteriophage T4 gene 45 protein, gp45, serves as the sliding clamp of viral DNA replication and as the activator of T4 late gene transcription. In the latter context, DNA tracking is an essential feature of the unique mechanism of action. T4 late promoters, which consist of a simple TATA box, TATAAATA, are recognized ... |
8890154 | Structure-function analysis of the Escherichia coli GrpE heat shock protein. | We have isolated various missense mutations in the essential grpE gene of Escherichia coli based on the inability to propagate bacteriophage lambda. To better understand the biochemical mechanisms of GrpE action in various biological processes, six mutant proteins were overexpressed and purified. All of them, GrpE103, ... |
8889246 | Heteromorphic sex chromosomes in Eupsophus insularis (Amphibia: Anura: Leptodactylidae). | The chromosomes of the Chilean frog Eupsophus insularis are described for the first time. This species has a chromosome number of 2n = 30, and based on the karyotype it is concluded that E. insularis is closely related to E. migueli. E. insularis has an XX/XY system of sex determination, and pericentromeric constitutiv... |
8889245 | Organization of DNA topoisomerase II isotypes during the cell cycle of human lymphocytes and HeLa cells. | We have monitored the organization of DNA topoisomerase II (Topo II) in relation to chromatin disaggregation during mitogen stimulation of lymphocytes and to the mitotic chromosome condensation cycle by immunofluorescence microscopy with isozyme-specific antibodies. Labelling for both Topo II alpha and Topo II beta was... |
8889244 | G- and R-banded prometaphase karyotypes in cattle (Bos taurus L.). | G- and R banded cattle (Bos taurus L.) karyotypes at about 500 band level are reported and discussed in light of chromosome banding standard nomenclature discrepancies. GTG-, GBG-, RBA- and RBG-banded karyotypes were arranged according to the Reading Conference standard. The G- and R-banding patterns of small acrocentr... |
8889243 | Human chromosome 3: high-resolution fluorescence in situ hybridization mapping of 40 unique NotI linking clones homologous to genes and cDNAs. | Forty new NotI linking clones representing sequence tagged sites (STSs) were mapped by fluorescence in situ hybridization (FISH) to different regions of human chromosome 3 (HSA3). Clone NL1-245, containing human aminoacylase 1, was localized to 3p21.2-p21.1. Our previous localization of the CLC-2 chloride channel prote... |
8889242 | Are proteasomes involved in the formation of the kinetochore? | Proteasomes catalyse the degradation of proteins responsible for the regulation of mitosis enabling the cell to complete cell division. We have studied the effect of an inhibitor of the chymotrypsin-like activity of the proteasome on the trilaminar structure of the kinetochore in HeLa cells. Whereas a role for the prot... |
8889241 | Conservation of a 31-bp bovine subrepeat in centromeric satellite DNA monomers of Cervus elaphus and other cervid species. | A centromeric satellite DNA clone was isolated from the genome of the European red deer (Cervus elaphus hippelaphus) and designated Ce-Pst1. This clone was localized to the centromeric region of all red deer chromosomes with the exception of a single pair of metacentric autosomes and the Y chromosome. DNA sequence anal... |
8889240 | Characterization of DNA sequences constituting the terminal heterochromatin of the chicken Z chromosome. | Two clones, pCZTH5-8 and pCZTH12-8, were isolated from a female chicken genomic library by screening with sequences obtained from genomic libraries which had been constructed from a terminal region of a single Z chromosome of chicken utilizing laser microbeam irradiation and PCR amplification. Fluorescence in situ hybr... |
8887560 | Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae. | A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at ... |
8887551 | Spc110p: assembly properties and role in the connection of nuclear microtubules to the yeast spindle pole body. | Spc110p is an essential component of the budding yeast spindle pole body (SPB). It binds calmodulin and contains a long central coiled-coil rod which acts as a spacer element between the central plaque of the SPB and the ends of the nuclear or spindle microtubules. This suggests that the essential function of Spc110p i... |
8886982 | Alterations in neural intermediate filament organization: functional implications and the induction of pathological changes related to motor neuron disease. | The properties regulating the supramolecular organization of neural intermediate filament (NIF) networks have been investigated in cultured dorsal root ganglion (DRG) neurons. The studies described take advantage of the ability of endogenous NIF to incorporate purified biotinylated neurofilament triplet (NFT) proteins,... |
8886422 | Role of bradykinin receptors in the renal effects of inhibition of angiotensin converting enzyme and endopeptidases 24.11 and 24.15 in conscious rabbits. | 1. We tested the effects on systemic haemodynamics and renal function, of inhibition of endopeptidase (EP) 24.15 (E.C. 3.4.24.15), in conscious uninephrectomized rabbits in which the activities of angiotensin converting enzyme (ACE, E.C. 3.4.15.1) and neutral endopeptidase (EP 24.11, E.C. 3.4.24.11) were already inhibi... |
8886410 | The stimulation of capsaicin-sensitive neurones in a vanilloid receptor-mediated fashion by pungent terpenoids possessing an unsaturated 1,4-dialdehyde moiety. | 1. The irritant fungal terpenoid isovelleral caused protective eye-wiping movements in the rat upon intraocular instillation and showed cross-tachyphylaxis with capsaicin, the pungent principle in hot pepper. 2. Isovelleral induced a dose-dependent calcium uptake by rat dorsal root ganglion neurones cultured in vitro w... |
8886396 | Depression of glutamatergic transmission by nociceptin in the neonatal rat hemisected spinal cord preparation in vitro. | The present study explored the action of nociceptin, the putative endogenous ligand for the orphan opioid receptor (ORL1), on the rat hemisected spinal cord preparation. Electrical stimulation of a dorsal root evokes a glutamatergic population ventral root potential (DR-VRP) in the corresponding ventral root. Low inten... |
8884182 | Liarozole potentiates the all-trans-retinoic acid-induced structural remodelling in human breast carcinoma MCF-7 cells in vitro. | Liarozole inhibits cytochrome P-450-dependent enzymes that play a key role in all-trans-retinoic acid (ATRA) catabolism. In MCF-7 cells, liarozole potentiates the antiproliferative effects of ATRA. The present study demonstrates this synergistic effect on cell differentiation of MCF-7 cell cultures as measured by immun... |
8880921 | Members of the immunoglobulin superfamily in bacteria. | We report a prediction that two prokaryotic proteins contain immunoglobulin superfamily domains. Immunoglobulin-like folds have been identified previously in prokaryotic proteins, but these share no recognizable sequence similarity with eukaryotic immunoglobulin superfamily (IgSF) folds, and may be the result of the ph... |
8880920 | Conformational flexibility and crystallization of tandemly linked type III modules of human fibronectin. | Fibronectin is a large cell adhesion molecule that is composed of several functional domains. The cell-binding domain that binds to cell surface integrins consists of repeated homologous type III modules. In this study, recombinant fragments from the cell-binding domain of human fibronectin that participate in a newly ... |
8880917 | Homology modeling of human methylmalonyl-CoA mutase: a structural basis for point mutations causing methylmalonic aciduria. | Point mutations in the human gene encoding coenzyme B12 (adenosylcobalamin)-dependent methylmalonyl-CoA mutase give rise to an inherited disorder of propionic acid metabolism termed mut methylmalonic aciduria. Almost all such mutations alter amino acids in the homodimeric human enzyme that are identical to residues in ... |
8880916 | Dynamic NMR studies of ligand-receptor interactions: design and analysis of a rapidly exchanging complex of FKBP-12/FK506 with a 24 kDa calcineurin fragment. | Dynamic NMR methods, such as differential line broadening and transferred NOE spectroscopy, are normally reserved for the study of small molecule ligand interactions with large protein receptors. Using a combination of isotope labeling and isotope edited NMR, we have extended these techniques to characterize interactio... |
8880915 | Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease. | The nucleases A produced by two strains of Staphylococcus aureus, which have different stabilities, differ only in the identity of the single amino acid at residue 124. The nuclease from the Foggi strain of S. aureus (by convention nuclease WT), which contains His124, is 1.9 kcal.mol-1 less stable (at pH 5.5 and 20 deg... |
8880157 | Course of the optic nerve fibers through the lamina cibrosa in human eyes. | <h4>Background</h4>This study investigated whether regional variations in the course of the optic nerve fibers through the lamina cribrosa may be one of the reasons why the local susceptibility for glaucomatous optic nerve fiber loss differs among the various regions of the optic disc.<h4>Methods</h4>The study included... |
8878612 | Systemic availability of itraconazole in lung transplantation. | Systemic availability of itraconazole in lung transplantation was evaluated by serially measuring the bioactivity of itraconazole in lung transplant patients who received itraconazole for prophylaxis (n = 12) or therapy (n = 5). These patients also received concomitant antacid and H2 blocker therapy. In patients receiv... |
8878599 | Chemical Determinants of antimalarial activity of reversed siderophores. | Reversed siderophores (RSFs) are artificial hydroxamate-based iron chelators designed after the natural siderophore ferrichrome. The modular molecular design of RSF derivatives allowed the synthesis of various congeners with controlled iron-binding capacities and partition coefficients. These two physicochemical proper... |
8878594 | Genetic characterization of trimethoprim resistance in Haemophilus influenzae. | We previously demonstrated that trimethoprim (Tmp) resistance in Haemophilus influenzae is mediated by chromosomally encoded dihydrofolate reductase (DHFR) with a modified primary structure and distinct kinetic properties. To gain insight into the relationship of the DHFR structure and the level of Tmp resistance that ... |
8878568 | Molecular aspects of high-level resistance to sulbactam-cefoperazone in Klebsiella oxytoca clinical isolates. | Nine Klebsiella oxytoca strains which demonstrated resistance to the combination of sulbactam and cefoperazone were isolated from geographically separate hospitals in Japan in 1995. Among them, K. oxytoca SB23 showed high-level resistance to sulbactam-cefoperazone (MIC > 128 micrograms/ml) and aztreonam (MIC, 128 micro... |
8877142 | Identification of serum and urine proteins responsible for enhanced pigment production by group B streptococci as amylases. | The serum and urine proteins responsible for enhanced pigment production in Streptococcus agalactiae in culture media were purified by chromatography and were identified as amylases by comparison of their amino acid composition with that calculated for proteins with known sequences. Similar pigment-enhancing activity w... |
8876832 | Ultrastructure of the crotaline snake infrared pit receptors: SEM confirmation of TEM findings. | <h4>Background</h4>Crotaline snakes possess a pair of infrared-sensing pit organs that aid the eyes in the detection and apprehension of prey. The morphology of the receptors in the pit organs has been studied by light and transmission electron microscopy, and the ultrastructure of the receptors has been inferred from ... |
8874015 | Oriented 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine/ganglioside membranes: a Fourier transform infrared attenuated total reflection spectroscopic study. Band assignments; orientational, hydrational, and phase behavior; and effects of Ca2+ binding. | Fourier transform infrared (FTIR) attenuated total reflection (ATR) spectroscopy was used to elucidate the hydration behavior and molecular order of phospholipid/ganglioside bilayers. We examined dry and hydrated films of the gangliosides GM1, deacetyl-GM1, lyso-GM1, deacetyllyso-GM1, and GM3 and oriented mixed films o... |
8874011 | Spontaneous formation of interfacial lipid-protein monolayers during adsorption from vesicles. | Spread and adsorbed monolayers of lipid-protein mixtures have served as models for biomembranes and pulmonary surfactant, but their similarity was unclear. Epifluorescence microscopy of monolayers spontaneously adsorbed from vesicles of dipalmitoylphosphatidylcholine or dipalmitoylphosphatidylcholine plus surfactant pr... |
8874005 | Interaction between ion channel-inactivating peptides and anionic phospholipid vesicles as model targets. | Studies of rapid (N-type) inactivation induced by different synthetic inactivating peptides in several voltage-dependent cation channels have concluded that the channel inactivation "entrance" (or "receptor" site for the inactivating peptide) consists of a hydrophobic vestibule within the internal mouth of the channel,... |
8874004 | Use dependence of tetrodotoxin block of sodium channels: a revival of the trapped-ion mechanism. | The use-dependent block of sodium channels by tetrodotoxin (TTX) has been studied in cRNA-injected Xenopus oocytes expressing the alpha-subunit of rat brain IIA channels. The kinetics of stimulus-induced extra block are consistent with an underlying relaxation process involving only three states. Cumulative extra block... |
8873994 | Spontaneous vesicle formation at lipid bilayer membranes. | Unilamellar vesicles are observed to form spontaneously at planar lipid bilayers agitated by exothermic chemical reactions. The membrane-binding reaction between biotin and streptavidin, two strong transmembrane neutralization reactions, and a weak neutralization reaction involving an "antacid" buffer, all lead to spon... |
8866028 | Kinetics of anhydride formation in xerogels of poly(acrylic acid). | The aim of this work was to study the cross-linkage of xerogels made of Carbopol of different molecular weight (polymers deriving from polyacrylic acid), and the influence exerted by different percentages of beta-cyclodextrin upon the cross-linkage percentage. Xerogels were obtained by high-pressure compression and cro... |
8864223 | Interglycosidic acetals. Part 3. Synthesis and structure determination of cyclic monobenzylidene acetals of cyclodextrin derivatives bridging between two contiguous D-glucopyranosyl residues. | Transacetalation of fully 6-O-pivaloylated alpha-, beta-, and gamma-cyclodextrins with benzaldehyde dimethylacetal in the presence of (+)-10-camphorsulfonic acid gave monobenzylidene acetals (4, 5, 6) in moderately good yields. Benzylation of the beta-cyclodextrin derivative 5 followed by acid-catalyzed hydrolysis of t... |
8864220 | Investigation of the conformational behaviour of permethylated cyclodextrins by molecular modelling. | Conformations of manually built native and permethylated alpha-, beta-, and gamma-cyclodextrins (CD) were investigated using various computer assisted molecular modelling methods. Calculations were carried by applying the MM+ and the Tripos force field. The influences of atomic charges on the macrocyclic conformations ... |
8862580 | Diagnosis of disseminated candidiasis by measurement of urine D-arabinitol/L-arabinitol ratio. | Relative amounts of D-arabinitol (fungal origin) and L-arabinitol (part of normal human metabolism) in urine were determined by gas chromatography and mass spectrometry from 61 hospitalized patients with hematological malignancies. Seventeen neutropenic patients with acute leukemia (with 53 samples) had disseminated ye... |
8856067 | Functional analysis of Glu380 and Leu383 of soybean beta-amylase. A proposed action mechanism. | Soybean beta-amylase, comprising a (beta/alpha)8-barrel core with a mobile loop, similar to that of triose phosphate isomerase, was mutated by site-directed mutagenesis at residues Glu380 and Leu383. X-ray crystallographic findings suggest that Glu380 is the counterpart of the catalytic site (Glu186) and that Leu383, l... |
8856060 | Activation and enzyme characteristics of a DNA-restrained phosphatase in chromatin-associated complexes. | DNA-bound polypeptide complexes composed of several non-histone polypeptides that resisted harsh DNA deproteinization procedures were characterized. The three major polypeptides of these complexes have molecular masses of 62, 52, and 40 kDa. They constitute supramolecular structures that reside on isolated DNA in dense... |
8843673 | Complete capillary electrophoretic separation of substance P and its metabolites at neutral pH using ionic run buffer additives. | Substance P (SP), a bioactive peptide that is present in the extracellular fluid of the brain at picomolar concentrations, has been proposed to be a neurotransmitter and a neuromodulator in the central and peripheral nervous systems. This paper describes the development of analytical methodology for the separation of S... |
8843658 | Investigation on enantiomeric separations of fluorenylmethoxycarbonyl amino acids and peptides by high-performance liquid chromatography using native cyclodextrins as chiral stationary phases. | A systematic study was carried out to investigate enantiomeric separations of fluorenylmethoxycarbonyl (FMOC) amino acids and their peptides. Twenty amino acids were derivatized by 9-fluorenylmethyl chloroformate (FMOC-Cl) and its analogues, FMOC-glycyl-Cl and FMOC-beta-alanyl-Cl. All derivatives were chromatographed o... |
8843148 | The masked cysteine residues in methylmalonyl-CoA mutase from Propionibacterium shermanii are essential for catalytic activity. | Two masked cysteine residues have been reported in methylmalonyl-CoA mutase from Propionibacterium shermanii, Cys-535 in the alpha-subunit and Cys-517 in the beta-subunit, which are revealed only after reduction of the denatured enzyme with dithiothreitol. It has been postulated that these residues are involved in disu... |
8840785 | Strategies for achieving high-level expression of genes in Escherichia coli. | Progress in our understanding of several biological processes promises to broaden the usefulness of Escherichia coli as a tool for gene expression. There is an expanding choice of tightly regulated prokaryotic promoters suitable for achieving high-level gene expression. New host strains facilitate the formation of disu... |
8836148 | Raw-starch-digesting and thermostable alpha-amylase from the yeast Cryptococcus sp. S-2: purification, characterization, cloning and sequencing. | A starch-degrading enzyme produced by the yeast Cryptococcus sp. S-2 was purified in only one step by using an alpha-cyclodextrin-Sepharose 6B column, and was characterized as an alpha-amylase (EC 3.2.1.1). The molecular mass and isoelectric point of purified alpha-amylase (AMY-CS2) were estimated to be 66 kDa and 4.2 ... |
8831772 | Principal components describing biological activities and molecular diversity of heterocyclic aromatic ring fragments. | Ten physicochemical variables have been calculated for each of 100 different aromatic rings. These variables were selected because of their potential involvement in the molecular recognition of drug-receptor binding interactions, and they include size, lipophilicity, dipole magnitude and orientation, HOMO and LUMO ener... |
8826858 | Evaluation of phenylpiperazines as targeting agents for neuroblastoma. | The potential of radiolabelled phenylpiperazines as agents for the detection and therapy of tumours of neural crest origin was evaluated by in vitro pharmacological studies with human neuroblastoma cell lines [SK-N-SH and SK-N-BE(2C)], and in vivo by biodistribution measurements. The ability of phenylpiperazines: 4-phe... |
8823161 | Solution structure of horse heart ferricytochrome c and detection of redox-related structural changes by high-resolution 1H NMR. | A model for the solution structure of horse heart ferricytochrome c has been determined by nuclear magnetic resonance spectroscopy combined with hybrid distance geometry-simulated annealing calculations. Forty-four highly refined structures were obtained using a total of 1671 distance constraints based on the observed ... |
8816813 | Rational interleukin 2 therapy for HIV positive individuals: daily low doses enhance immune function without toxicity. | When administered in high doses to HIV positive (HIV+) individuals, interleukin 2 (IL-2) causes extreme toxicity and markedly increases plasma HIV levels. Integration of the information from the structure-activity relationships of the IL-2 receptor interaction, the cellular distribution of the different classes of IL-2... |
8816797 | Reverse two-hybrid and one-hybrid systems to detect dissociation of protein-protein and DNA-protein interactions. | Macromolecular interactions define many biological phenomena. Although genetic methods are available to identify novel protein-protein and DNA-protein interactions, no genetic system has thus far been described to identify molecules or mutations that dissociate known interactions. Herein, we describe genetic systems th... |
8816763 | Interaction between human tRNA synthetases involves repeated sequence elements. | Aminoacyl-tRNA synthetases (tRNA synthetases) of higher eukaryotes form a multiprotein complex. Sequence elements that are responsible for the protein assembly were searched by using a yeast two-hybrid system. Human cytoplasmic isoleucyl-tRNA synthetase is a component of the multi-tRNA synthetase complex and it contain... |
8812863 | Overexpression, purification, and characterization of recombinant barley alpha-amylases 1 and 2 secreted by the methylotrophic yeast Pichia pastoris. | Recombinant barley alpha-amylase isozymes 1 and 2 were secreted by Pichia pastoris at up to 50 and 1 mg/liter, respectively, representing approximately a 50-fold increase compared to the levels of the heterologous expression by Saccharomyces cerevisiae. The cDNA clones E or pM/C encoding isozymes 1 and 2, respectively,... |
8811099 | In vivo analysis of the plasmid pAM beta 1 resolution system. | The promiscuous plasmid pAM beta 1 from Gram-positive bacteria encodes a resolution system which differs from that of Tn3 in that (i) it requires a histone-like protein and an unusual resolvase-DNA interaction to promote recombination and (ii) it mediates in vivo DNA inversion in plasmid substrates. In this in vivo ana... |
8811096 | High-affinity and specific recognition of human thyroid stimulating hormone (hTSH) by in vitro-selected 2'-amino-modified RNA. | RNA sequences containing 2'-amino pyrimidines that bind with high-affinity to human thyroid stimulating hormone (hTSH) were isolated from a random sequence library by an in vitro selection-amplification procedure. A representative RNA ligand (T-15) has an equilibrium dissociation constant (Kd) of 2.5 nM for its interac... |
8809172 | Rediscovering an endothelin antagonist (BQ-123): a self-deconvoluting cyclic pentapeptide library. | A "self-deconvoluting" cyclic pentapeptide library, designed to produce 82,944 head-to-tail-linked peptides in 48 vials, has been prepared. The mixture included amino acids found in a recently optimized endothelin antagonist, BQ-123, originally isolated from microbial sources by Banyu investigators. Using a positional ... |
8809169 | Structure-activity relationships of novel hematoregulatory peptides. | Hematopoiesis is a lifelong cell renewal process regulated by a family of lineage specific hematopoietic growth factors. Several hematopoietic growth factors such as G-CSF, GM-CSF, and M-CSF have been clinically evaluated for enhancement of host defense in normal and immunocompromised patients and for the treatment of ... |
8809038 | Cross-link analysis of the C-telopeptide domain from type III collagen. | Several peptides were isolated from tryptic digests of insoluble calf aorta matrix by chromatography. Reductive pyridylethylation of a tryptic 15 kDa pool released fragments deriving from the C-terminus of type III collagen. A 50-residue peptide Tc(III) was shown by sequence analysis to be the C-terminal peptide from t... |
8809032 | Determination of the primary target for isoniazid in mycobacterial mycolic acid biosynthesis with Mycobacterium aurum A+. | The target of the potent antituberculosis drug isoniazid was investigated in Mycobacterium aurum A+, against which isoniazid has an MIC (the minimum concentration required to give growth inhibition) of 0.3 microgram/ml. Mycolic acid biosynthesis, measured by the incorporation of label from [1-14C]acetate into mycolic a... |
8806751 | The conformational state of human alpha 2-macroglobulin influences its dissociation into half-molecules by sodium thiocyanate. | Sodium thiocyanate dissociates native human alpha 2-macroglobulin into half-molecules consisting of two disulfide-bonded subunits, when the salt concentration is equal to or exceeds 1.2 M. Incubation with 1.6 M sodium thiocyanate for 1 h at 22 degrees C dissociates about 90% of alpha 2-macroglobulin into half-molecules... |
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