| structural alterations of horseradish peroxidase in the presence of low concentrations of guanidinium chloride. | the presence of very low concentrations of guanidinium chloride (gdmcl) alters the tertiary structure of the monomeric heme-containing enzyme, horseradish peroxidase (hrp). the change in tertiary structure of the protein was reflected in the mean fluorescence lifetime of its single tryptophan residue, which increased from 2.3 +/- 0.1 ns in the native enzyme to 2.7 +/- 0.2 ns in the presence of 100 mm gdmcl. more convincing evidence in support of such alterations came from quenching study of tryp ... | 1996 | 8917443 |
| the distal glutamic acid as an acid-base catalyst in the distal site of horseradish peroxidase. | the distal his is an essential amino acid residue as a general acid-base catalyst for peroxidase reaction cycle. however, the x-ray structure of chloroperoxidase revealed that glu is located near the heme, suggesting that the carboxyl group also assists cleavage of o-o bond in peroxides. in this paper, we examined functional and structural properties of a horseradish peroxidase mutant having glu instead of the distal his. although this amino acid replacement depressed reaction rate with h2o2 and ... | 1996 | 8878526 |
| rescue of his-42 --> ala horseradish peroxidase by a phe-41 --> his mutation. engineering of a surrogate catalytic histidine. | formation of the ferryl (feiv=o) porphyrin radical cation known as compound i in the reaction of horseradish peroxidase (hrp) with h2o2 is catalyzed by his-42, a residue that facilitates the binding of h2o2 to the iron and subsequent rupture of the dioxygen bond. an h42a mutation was shown earlier to decrease the rate of compound i formation by a factor of approximately 10(6) and of guaiacol oxidation by a factor of approximately 10(4). in contrast, an f41a mutation has little effect on peroxida ... | 1996 | 8798724 |
| oxidation of porphyrinogens by horseradish peroxidase and formation of a green pyrrole pigment. | when humans or plants are exposed to certain chemicals which interfere with heme biosynthetic enzymes, porphyrinogen intermediates accumulate and are oxidized to cytotoxic porphyrins. here we have investigated the role of peroxidases in porphyrinogen oxidation. horseradish peroxidase (hrp) rapidly oxidizes uroporphyrinogen to uroporphyrin and this is inhibited by ascorbic acid. hrp also oxidizes deuteroporphyrinogen (a synthetic porphyrin similar to protoporphyrinogen), but the yield of porphyri ... | 1996 | 8858124 |
| location of motoneurons supplying tail muscles in the domestic fowl. | the distribution of motoneurons innervating the tail muscles, levator caudae, depressor caudae, pubocaudalis externus, pubocaudalis internus, lateralis caudae and flexor cruris, in the adult domestic fowl was examined by retrograde transport of horseradish peroxidase labeled motoneurons supplying tail muscles were distributed in longitudinal column in the spinal cord below sacral spinal segment 3 and average diameters of cell bodies ranged from 27 to 59 microns. each motor pool was localized in ... | 1996 | 8933919 |
| detection of glycolipids as biotinylated derivatives using enhanced chemiluminescence. | a new method for the detection of glycolipids as biotinylated derivatives is presented. this method is based on the detection of lipids by enhanced chemiluminescence (ecl) following conjugation with streptavidin-horseradish peroxidase (shrp). partial biotinylation of glycolipids is achieved after mild oxidation of the glycan moiety with na-meta-periodate to increase the availability of biotin-reactive sites. there are several significant advantages of the glycolipid ecl detection: it avoids the ... | 1996 | 8921166 |
| biochemical method for chlorine dioxide determination. | chlorine dioxide is a disinfectant used worldwide. in this article, a new enzymatic method for the determination of chlorine dioxide has been developed. this rapid spectophotometric assay is able to detect from 0.2 to 4 mg/liter of chlorine dioxide. the method is based on the capacity of horseradish peroxidase to decolorize reactive yellow 17 in the presence of chlorine dioxide. the effects of several compounds on the assay have been determined. except sodium hypochlorite, no interference was de ... | 1996 | 8921159 |
| enzyme-coupled assays for proteases. | we have developed a general strategy for assaying proteases that does not require the use of fluorogenic, chromogenic, or radiolabeled peptide substrates. the endo- or exoproteolytic hydrolysis of simple peptides can be followed spectrophotometrically by coupling the proteolytic event via enzyme-catalyzed reactions to a chromogenic redox dye. the couple can be used directly to follow the action of carboxy or amino peptidases on peptide substrates or can be coupled by use of carboxy or amino pept ... | 1996 | 8921156 |
| refinement of 3d models of horseradish peroxidase isoenzyme c: predictions of 2d nmr assignments and substrate binding sites. | in this study, two alternative three-dimensional (3d) models of horseradish peroxidase (hrp-c)-differing mainly in the structure of a long untemplated insertion-were refined, systematically assessed, and used to make predictions that can both guide and be tested by future experimental studies. a key first step in the model-building process was a procedure for multiple sequence alignment based on structurally conserved regions and key conserved residues, including those side chains providing liga ... | 1996 | 8916228 |
| immunocytochemistry of brain phosphoproteins, protein kinases, and phosphatases | phosphoproteins and their associated kinases and phosphatases play a major role in second messenger signal cascades in neurons. immunocytochemical studies have shown that some of these phosphoproteins and their associated enzymes are homogeneously distributed in brain and function in signal cascades common to all neurons. other phosphoproteins and their associated enzymes are heterogeneously distributed and function in signal cascades related to specific neuronal subpopulations. phosphoproteins ... | 1996 | 8812664 |
| nonsteroidal antiinflammatory drugs interact with horseradish peroxidase in an in vitro assay system for hydrogen peroxide scavenging. | the established horseradish peroxidase/guaiacol in an in vitro assay system was used for investigation of the reactivity of nonsteroidal antiinflammatory drugs with hydrogen peroxide. although the drugs rapidly seemed to react in the selected conditions, difficulties were encountered in attempts to quantify the reaction and an interaction with horseradish peroxidase was suspected. a more specific assay system based on the absolute specificity of the enzyme glutathione peroxidase for glutathione ... | 1996 | 8891607 |
| generation of colorimetric, dual signals from two different enzymes by using catalytic ph shift. | because enzymes usually require distinct ph conditions for maximum activity, an approach of spontaneous ph shift of solution was devised to derive multiple reactions in a sequence. the two enzymes selected, horseradish peroxidase (hrp) and beta-galactosidase (gal), had dissimilar optimal ph levels, i.e., 5.1 and 7.0, respectively. in a solution, hrp initially reacted at a lower ph range and the gal reaction was consecutively carried out at a higher range in the presence of a third enzyme, urease ... | 1996 | 18629823 |
| trans-2-phenylcyclopropylamine is a substrate for and inactivator of horseradish peroxidase. | horseradish peroxidase (hrp) is well known for mediating the electron-transfer oxidation of electron-rich aromatic 'donors' such as phenols and anilines, but has not been described to oxidize aliphatic amines. we here confirm the inability of hrp to oxidize typical aliphatic amines, even those which would exist significantly as free bases at the operative ph. in contrast, trans-2-phenylcyclopropylamine (2-pcpa) is both a substrate (turnover product is cinnamaldehyde) and a time-dependent inactiv ... | 1996 | 8814233 |
| comparison of three chemiluminescent horseradish peroxidase substrates for immunoblotting. | | 1996 | 8811928 |
| structural features of crayfish phasic and tonic neuromuscular terminals. | we examined the fine structure of terminals of the phasic and tonic excitatory axon to the crayfish limb extensor muscle. the phasic terminals are known to release 50-100 times more transmitter for a small length of terminal for a single impulse. phasic terminals labeled with horseradish peroxidase (hrp) were relatively thin and contained a single unbranched mitochondrion; tonic terminals were much thicker, and their varicosities contained several multibranched mitochondria. tonic terminals devo ... | 1996 | 8876457 |
| secondary vestibulo-oculomotor projections in larval sea lamprey: anterior octavomotor nucleus. | the ventral octavolateral area of lampreys contains three nuclei: the anterior, intermediate and posterior octavomotor nuclei, formed of large neurons that are contacted by thick primary vestibular fibres. we used horseradish peroxidase (hrp) or fluorescein-dextran-amine (fda) labelling to study the projections of the anterior octavomotor nucleus (aon) in the larval sea lamprey, petromyzon marinus. the tracers were injected either in the aon, the oculomotor nucleus or the rostralmost spinal cord ... | 1996 | 8876454 |
| gabaergic synapses in the antennal lobe and mushroom body of the locust olfactory system. | to help elucidate the role of inhibitory feedback in the genesis of odour-evoked synchronization of neural activity, we investigated the distribution of gamma-aminobutyric acid (gaba)ergic synaptic terminals in the antennal lobes (al) and mushroom bodies (mb) of the locust olfactory system. electron-microscopy, intracellular horseradish peroxidase labelling, and immunocytochemistry were combined to assess the distribution of gabaergic synapses, using established methods (leitch and laurent [1993 ... | 1996 | 8876449 |
| linamarin sensors: interference-based sensing of linamarin using linamarase and peroxidase. | an interference-based linamarin sensor is developed. horseradish peroxidase (hrp) is adsorbed on a pyrolytic graphite (pg) electrode, and then linamarase from cassava is cross-linked with glutaraldehyde on the electrode surface. the prepared bienzyme electrode is poised at -300 mv vs ag/agcl for 40 s to reduce dissolved o(2) to h(2)o(2) at the pg surface. the potential is then stepped to 0 mv, at which point the accumulated h(2)o(2) is reduced, though the o(2) reduction does not proceed. since t ... | 1996 | 21619361 |
| 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 not bind hrp below ph 8.0. hrp was immobilized in an oriented and reversible fashion using this gel. the immobilized enzyme retained 90.12 per cent of its original activity, probably ... | 2012 | 9174924 |
| 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, horseradish peroxidase (hrp). hrp fibrils showed substantial catalytic activity. additionally, carboxyl fibrils were derivatized with specific inhibitors of the enzymes beta-galactosi ... | 2000 | 9174914 |
| immobilization and stabilization of horseradish peroxidase isoforms. | purified anionic and cationic isoforms of horseradish peroxidase (hrp) immobilized by coupling the amino acid side-chain amino groups and/or carbohydrate moieties to sepharose have been studied for their resistance to denaturation. the isoforms were treated with periodate followed by ethylenediamine to generate additional amino groups in the glycosyl residues. the immobilized preparations were: preparation i (sp-ahrp, sp-chrp), in which hrp was covalently immobilized via side-chain amino groups ... | 1996 | 8886264 |
| mediator-free amperometric determination of toxic substances based on their inhibition of immobilized horseradish peroxidase. | we have demonstrated the feasibility of quantitatively detecting selected toxic materials through their inhibitory effect on an enzyme electrode that utilizes colloidal gold-immobilized horseradish peroxidase and does not require a mediator. quantitative detection of azide, cyanide, thiourea, sulfide, and dichromate is demonstrated. the sensitivity and inhibition kinetics for this immobilized enzyme electrode are found to be different from those observed previously for homogeneous horseradish pe ... | 2007 | 8879158 |
| the initial stages of development of the retinocollicular projection in the wallaby (macropus eugenii): distribution of ganglion cells in the retina and their axons in the superior colliculus. | the time course of ingrowth of retinal projections to the superior colliculus in the marsupial mammal, the wallaby (macropus eugenii), was determined by anterograde labelling of axons from the eye with horseradish peroxidase, from birth to 46 days, when axons cover the colliculus contralaterally and ipsilaterally. the position of retinal ganglion cells giving rise to these projections over this period was determined in fixed tissue by retrograde labelling from the colliculus with a carbocyanine ... | 1996 | 8849677 |
| ca2+ activation of wheat peroxidase: a possible physiological mechanism of control. | peroxidation of substrates such as ascorbic acid, pyrogallol, or ferulic acid, as well as indole acetic acid oxidation catalyzed by wheat germ peroxidase (wgp)2 c2, were found to be activated by ca2+. this activation is independent of the stabilizing effect of structural ca2+ reported for peroxidases. steady state kinetics of ferulic acid oxidation catalyzed by wgp c2 showed an increase in the rate of compound i formation and of compound ii decomposition in the presence of the ion, evidenced as ... | 1996 | 8806754 |
| operant conditioning of h-reflex changes synaptic terminals on primate motoneurons. | operant conditioning of the primate triceps surae h-reflex, the electrical analog of the spinal stretch reflex, creates a memory trace that includes changes in the spinal cord. to define the morphological correlates of this plasticity, we analyzed the synaptic terminal coverage of triceps surae motoneurons from animals in which the triceps surae h-reflex in one leg had been increased (hrup mode) or decreased (hrdown mode) by conditioning and compared them to each other and to motoneurons from un ... | 1996 | 8799179 |
| synthesis and characterization of 4-iodophenylboronic acid: a new enhancer for the horseradish peroxidase-catalyzed chemiluminescent oxidation of luminol. | 4-iodophenylboronic acid has been synthesized and shown to be a potent enhancer of the chemiluminescent horseradish peroxidase (type vi-a)-catalyzed oxidation of luminol and isoluminol. the enhancer was effective (>100-fold enhancement) in the concentration range 10-1500 microm. light emission in the presence of the enhancer peaked at 5-10 min after initiation of the reaction and then decayed very slowly. 4-iodophenylboronic acid also enhanced reactions catalyzed by horseradish peroxidase type i ... | 1996 | 8811887 |
| microperoxidase/h2o2-catalyzed aromatic hydroxylation proceeds by a cytochrome-p-450-type oxygen-transfer reaction mechanism. | the mechanism of aromatic hydroxylation of aniline and phenol derivatives in a h2o2-driven microperoxidase-8(mp8)-catalyzed reaction was investigated. it was shown that the reaction was not inhibited by the addition of scavengers of superoxide anion or hydroxyl radicals, which demonstrates that the reaction mechanism differs from that of the aromatic hydroxylation catalyzed by a horseradish peroxidase/ dihydroxyfumarate system. additional experiments with 18o-labelled h2 18o2 demonstrated that t ... | 1996 | 8797858 |
| wheat germ agglutinin-reactive chains of giant hemoglobin from the polychaete perinereis aibuhitensis. | wheat germ agglutinin-reactive chains of multisubunit extracellular hemoglobin from the polychaete perinereis aibuhitensis were identified to clarify the carbohydrate gluing which is the carbohydrate-dependent supramolecular architecture of the hemoglobin (ebina s. et al. (1995) proc. natl. acad. sci. usa 92, 7367-7371). electron microscope micrographs of perinereis hemoglobin showed a characteristic shape of two-tiered hexagonal rings whose diameter and height were determined to be 29.4 +/- 1.7 ... | 1996 | 8765123 |
| intrinsic connections in the anterior dorsal ventricular ridge of the lizard psammodromus algirus. | we have studied the intrinsic connections of the anterior dorsal ventricular ridge (advr) in the lacertid lizard psammodromus algirus by means of retrograde transport of horseradish peroxidase (hrp) and fluorescent labeling with the lipophilic carbocyanine dye dii. we injected hrp into different regions in the advr arrayed in a medial-to-lateral sequence, with each consisting of three distinct superficial-to-deep zones. when hrp was injected into a given region, many labeled neurons (always loca ... | 1996 | 8841921 |
| direct projections from the spinal cord to the trigeminal sympathetic ganglion of the puffer fish, takifugu niphobles. | the sympathetic trunk of teleosts extends into the cranial levels, forming the cranial sympathetic ganglia. when horseradish peroxidase was applied to the trigeminal sympathetic ganglion (a sympathetic ganglion at the level of the trigeminal nerve) of the puffer fish, takifugu niphobles, retrogradely labeled neurons were found in the central autonomic nucleus (a distinct cell column in the rostral part of the spinal cord). the central autonomic nucleus has been known to contain preganglionic neu ... | 1996 | 8858622 |
| screen-printable sol-gel enzyme-containing carbon inks. | enzymes usually cannot withstand the high-temperature curing associated with the thick-film fabrication process and require a separate immobilization step in connection with the production of single-use biosensors. we report on the development of sol-gel-derived enzyme-containing carbon inks that display compatibility with the screen-printing process. such coupling of sol-gel and thick-film technologies offers a one-step fabrication of disposable enzyme electrodes, as it obviates the need for th ... | 1996 | 21619216 |
| in vitro comparative assessment of the antioxidant activity of nacystelyn against three reactive oxygen species. | thiol-containing molecules possess antioxidant properties that are of interest in the pharmacological inactivation of reactive oxygen species (ros), particularly in the treatment of chronic inflammatory respiratory diseases. in the present study, the in vitro antioxidant activity of a new agent was examined and compared with other thiol containing molecules, n-acetylcysteine (nac) and captopril. nacystelyn (cas 89344-48-9, nal) is a l-lysine salt of nac having demonstrated several advantages as ... | 1996 | 9125279 |
| hybridization of horseradish peroxidase-labeled probes and detection by enhanced chemiluminescence. | this article describes the use of probes directly labeled with horseradish peroxidase in conjunction with enhanced chemiluminescence, which allows a flexible approach to hybridizations and detections. this system may be used with the following applications: southern blots, northern blots, colony and plaque screening for positive clones, yac clone screening, and pcr products detection. the major steps required for the use of directly labeled hrp probes are hybridization, stringent washes, and det ... | 1996 | 8887363 |
| preparation of horseradish peroxidase-labeled probes. | the direct labeling of nucleic acid probes with horseradish peroxidase (hrp) may be used in many membrane hybridization applications, including southern blots, northern blots, colony and plaque screening, pcr products detection/identification. this article describes the preparation method, which involves the labeling of a single-stranded nucleic acid probe with a positively charged hrp-parabenzoquinone-polyethyleneimine complex (labeling reagent). the associated hybridization and posthybridizati ... | 1996 | 8887362 |
| direct determination of plasma endothelin-i by chemiluminescence enzyme immunoassay. | a highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-i (et-1), involving no extraction steps, has been developed. two populations of polyclonal antibodies were used in the present study: one is specific to the c-terminus of the endothelin family of peptides; the other, a fab' fragment against the n-terminal core region of et-1, is coupled with horseradish peroxidase (hrp). labeled hrp activity was measured by using an enhanced chemiluminescence reaction of ... | 1996 | 8697570 |
| temperature dependence of endocytosis in renal epithelial cells in culture. | temperature dependence of fluid-phase endocytosis was determined in two renal epithelial cell lines, mdck cells and llc-pk1 cells, using lucifer yellow or horseradish peroxidase as markers. for both cell lines, grown on solid support as a confluent monolayer, biphasic curves of marker uptake vs. temperature were obtained. the changes in slope occurred around 27 degrees c, a critical temperature at which the lipids of the plasma membrane of mdck cells enter in the gel state. activation energies w ... | 1996 | 8703969 |
| removal of chlorophenols from wastewater by immobilized horseradish peroxidase. | immobilization of horseradish peroxidase on magnetite and removal of chlorophenols using immobilized enzyme were investigated. immobilization by physical adsorption on magnetite was much more effective than that by the crosslinking method, and the enzyme was found to be immobilized at 100% of retained activity. in addition, it was discovered that horseradish peroxidase was selectively adsorbed on magnetite, and the immobilization resulted in a 20-fold purification rate for crude enzyme. when imm ... | 1996 | 18627096 |
| competitive immunosorbent assays using ligand-enzyme conjugates bifunctional liposomes: theory and experiment. | two models of immunoadsorbent assays are developed that describe the competitive adsorption of labeled antigen and unlabeled analyte to antibody binding sites immobilized on a solid surface. in the first model, a small labeled antigen and a small unlabeled analyte compete with only binding site limitations and no steric limitations. a multicomponent langmuir isotherm results that is sufficient to quantify competitive adsorption. this model can describe, with no adjustable parameters, the data of ... | 2013 | 8987478 |
| destabilization of plasma membrane structure by prevention of actin polymerization. microtubule-dependent tubulation of the plasma membrane. | electron microscopy of thick (0.2-1.0 micron) sections of cytochalasin d-treated cells fixed in the presence of ruthenium red revealed an extensive, surface-connected tubular compartment in hep-2 cells. the tubules measured 120-220 nm in diameter and at least up to 6 microns in length. morphometric analysis showed that in control cells about 0.2% of the total plasma membrane area (defined as all ruthenium red-labeled membrane) appeared as vesicular or tubular profiles beneath the cell surface. h ... | 1996 | 8832388 |
| horseradish peroxidase-catalyzed conjugation of eugenol with basic amino acids. | l-lysine is shown to yield an adduct with the quinone methide intermediate formed during the horseradish peroxidase (hrp)-catalyzed aerobic oxidation of eugenol (4-allyl-2-methoxyphenol). adduct formation is evidenced by (i) lysine quenching of the characteristic quinone methide absorption band measured at 350 nm; arginine and gamma-aminobutyric acid, but not alanine or propionic acid showed similar behaviour (ii) lysine-promoted a 400 mv decrease of the eugenol oxidation voltammetric wave (1.00 ... | 1996 | 8814439 |
| motor nuclei of nerves innervating the tongue and hypoglossal musculature in a caecilian (amphibia:gymnophiona), as revealed by hrp transport. | the organization of the motor nuclei of the glossopharyngeal, vagal, occipital, first spinal and second spinal nerves of typhlonectes natans (amphibia: gymnophiona: caeciliaidae: typhlonectinae) was studied by using horseradish peroxidase reaction staining. each nucleus has discrete patterns of cytoarchitecture and of topography. nuclei are elongate and some overlap anteroposteriorly. the brainstem is elongate, with no distinct demarcation of brainstem from spinal cord. the occipital nerve emerg ... | 1996 | 8799860 |
| influence of forskolin and carbachol on intestinal absorption of horseradish peroxidase in the goldfish (carassius auratus). | the transepithelial route for mucosa-to-serosa transport of the tracer macromolecule horseradish peroxidase (hrp; mw 40 kda) and modulation of this transport by forskolin and carbachol have been studied in vi-tro in stripped goldfish intestinal epithelium mounted in ussing-type chambers. uptake and transport have been investigated by measuring the hrp flux from the muco-sal to serosal sides by an enzymatic method and by visualising hrp reaction products in the mucosa with electron-microscopical ... | 1996 | 8766857 |
| enhanced absorption of macromolecules. a secondary factor in crohn's disease. | we explored the function of the intestine's mucosal barrier to foreign antigen entry in crohn's disease. macroscopically and microscopically uninvolved areas of the small intestines of patients with crohn's disease were examined. we studied 27 endoscopic biopsy samples from 17 patients with crohn's disease and 14 samples from nine controls. the absorption and degradation of horseradish peroxidase (molecular weight 40,000 da) were studied in ussing chambers. the absorption of intact horseradish p ... | 1996 | 8689920 |
| synaptic connection between olfactory receptor cells and uniglomerular projection neurons in the antennal lobe of the american cockroach, periplaneta americana. | both antennal receptor cell axons and uniglomerular projection neurons of the antennal lobe were specifically labeled, and their synaptic relationship was studied at the fine structural level. the labelings were applied in different combinations: i) experimentally induced anterograde degeneration of sensory-afferent axons was combined with injection of horseradish peroxidase into uniglomerular projection neurons. ii) lucifer yellow was injected into uniglomerular projection neurons, and receptor ... | 1996 | 8797155 |
| experimental procedure for a hydrogen peroxide assay based on the peroxidase-oxidase reaction. | a low-cost assay method that is able to measure h2o2 concentrations as low as the nano-molar range is described. the assay solution contains nadh, horseradish peroxidase, and superoxide dismutase at ph 7.5. after the addition of the sample, the decrease in nadh concentration measured by spectrophotometry is proportional to the h2o2 concentration. because of superoxide dismutation, a high amplification factor defined as moles nadh oxidised per mole h2o2 added is obtained, which allows the sensiti ... | 1996 | 8706681 |
| lectin affinity electrophoresis of alpha-fetoprotein detected by immunoenzymatic and chemiluminescent amplification followed by direct scanning. | microdetermination of alpha-fetoprotein (afp) glycoforms by lectin affinity electrophoresis followed by chemiluminescence reaction using horseradish peroxidase (pod) or alkaline phosphatase (alp) in antibody-affinity blotting was developed. the intensity of chemiluminescence obtained by alp was greater than that by pod; however, the coefficient of variation with pod was less than that with alp. the optimized sensitivity of the chemiluminescence method with pod was two times that of the most sens ... | 1996 | 8805850 |
| generation of polyclonal antibodies against nisin: immunization strategies and immunoassay development. | murine polyclonal antibodies reactive to the lantibiotic bacteriocin nisin a (nisa) have been produced by immunization with nisa-cholera toxin and nisa-keyhole limpet hemocyanin (nisa-klh) conjugates. mice immunized with nisa-cholera toxin developed nisa-specific antibodies with low relative affinities and poor sensitivities, while the immunization of mice with nisa-klh conjugates resulted in the production of nisa-specific antibodies with high relative affinities and much-increased sensitivitie ... | 1996 | 8787409 |
| h(2)o(2)-generating peroxidase electrodes as reagentless cyanide sensors. | inexpensive, reagentless, and simple (single-electrode) cyanide biosensors are developed using a pyrolytic graphite (pg) electrode on which horseradish peroxidase (hrp) is adsorbed. the electrode is poised at -300 mv vs ag/agcl for 40 s to reduce dissolved o(2) to h(2)o(2) at the pg surface. the generated h(2)o(2) accumulates in the diffusion layer. the potential is then stepped to 0 mv, at which the accumulated h(2)o(2) is reduced, though the o(2) reduction does not proceed. since the h(2)o(2) ... | 1996 | 21619128 |
| [conjugation of lectins with horseradish peroxidase: an improved method]. | | 2006 | 8925222 |
| super-sensitive enzyme immunoassay for thyroid stimulating hormone using a new synergistic enhanced chemiluminescent endpoint. | the enhancers 1,1'-biphenyl-4-yl boronic acid and 4-iodophenol act synergistically in the horseradish peroxidase-catalysed oxidation of luminol. this concentration-dependent effect reduces background, increases signal and hence improves signal/background for detection of peroxidase. the same type of synergistic effect was found when 1,1'-biphenyl-4-yl boronic acid was added to a commercial enhanced chemiluminescence signal reagent (amerlite signal reagent). this synergistic enhanced chemilumines ... | 2013 | 8844344 |
| role of the reductant substrates on the inactivation of horseradish peroxidase by m-chloroperoxybenzoic acid. | horseradish peroxidase reacts with h2o2 and other hydroperoxides to form compound i, the first active enzymatic form m-chloroperoxybenzoic acid, a xenobiotic hydroperoxide, acts as an oxidant substrate of horseradish peroxidase. however, this hydroperoxide is also a powerful inactivator of the enzyme and in this sense is more effective than h2o2. the coupled reductant substrates used in the peroxidatic reaction protect the enzyme from the inactivating process. a reaction mechanism is proposed wi ... | 1996 | 8799332 |
| enzyme immunoassay for conjugated cholic and 1 beta-hydroxycholic acids in urine of early infancy. | a direct competitive heterologous enzyme immunoassay (eia) for conjugated cholic acid (ca) was developed using horseradish peroxidase labeled antigen having a shorter bridge length than that of the immunogen. an appropriate dose-response curve for conjugated ca was obtained in the range of 0.05-50 ng/well. specificity of the eia proved satisfactory in terms of cross-reactivities to 23 kinds of related bile acids. the proposed method was evaluated to be useful for the determination of conjugated ... | 1996 | 8744281 |
| spectroscopic analysis of charge transfer complex formation and peroxidase inhibition with tricyclic antidepressant drugs: potential anti-thyroid action. | inspection of the chemical structures of tricyclic antidepressant drugs indicates that they might interfere with the synthesis of thyroid hormones. this iatrogenic potential was demonstrated in vitro by the spectrophotometric detection in both the visible and uv regions of the formation of a complex between antidepressants and iodine. the values of kc, the formation constant of the drug-iodine complex, were calculated. the concentration of antidepressant which led to a 50% inhibition (ic50) of h ... | 1996 | 8741583 |
| cortical target depletion and the developing lateral geniculate nucleus: implications for trophic dependence. | the dependence of the developing dorsal lateral geniculate nucleus (lgd) on visual cortex for survival has been well documented. complete removal of visual cortex during early postnatal development results in degeneration of the lgd. to further explore the nature of this trophic relationship, we depleted variable proportions of the principal targets of geniculocortical axons, layer iv neurons, and also variable proportions of the supragranular neurons by intraperitoneal injections of different d ... | 2015 | 8670670 |
| inhibition by l-ascorbic acid and other antioxidants of the 2.2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) oxidation catalyzed by peroxidase: a new approach for determining total antioxidant status of foods. | the accumulation of 2.2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (abts) radical catalyzed by peroxidase can be inhibited by the presence of l-ascorbic acid in the reaction medium, this inhibition delaying the accumulation of the abts radical and giving rise to a lag time. a kinetic approach to explain this lag time is presented, which also makes it possible to determine the amount of l-ascorbic acid in the reaction medium. the stoichiometry of the system was determined as 1 mol of l-asc ... | 1996 | 8660502 |
| detection of multiple antigens on western blots. | an immunoblotting method is described that permits sequential detection of multiple antigens on a single protein blot without stripping off prior antibodies. the procedure utilizes horseradish peroxidase (hrpase)-based detection with a chemiluminescent substrate. after detection by enhanced chemiluminescence (ecl) with exposure to x-ray film, the antigen-antibody complexes on the blot are reacted with a chromogenic substrate (either 3.3'-diaminobenzidine [dab] or sg [vector labs, inc.]) which re ... | 1996 | 8660498 |
| ftir study of the thermal denaturation of horseradish and cytochrome c peroxidases in d2o. | fourier transform infrared (ftir) spectroscopy was employed to examine the thermal denaturation of the fe(iii), fe(ii), and fe(ii)-co forms of cytochrome c peroxidase and horseradish peroxidase in phosphate buffer at pd 7.0. the amide i' regions of the deconvolved spectra are consistent with predominantly alpha-helical secondary structure around room temperature, but the alpha-helical absorption of the two peroxidases differs significantly; bands assigned to alpha-helical components occur at 165 ... | 1996 | 8611540 |
| somatotopic organization of the facial lobe of the sea catfish arius felis studied by transganglionic transport of horseradish peroxidase. | to reveal the somatotopical organization of the facial lobe (fl), a primary medullary gustatory nucleus in the sea catfish arius felis, the central projections of the peripheral rami of the facial nerve innervating taste buds located across the entire body surface and rostral oral regions were traced by means of horseradish peroxidase neurohistochemistry. the maxillary barbel, lateral mandibular barbel, medial mandibular barbel, and trunk-tail branches project to four different longitudinal colu ... | 1996 | 8725297 |
| luminometry: a novel bioluminescent immunoassay enhances the quantitation of mucosal and systemic antibody responses. | we have directly compared enzyme-linked immunoassays (elisas) with bioluminescent immunoassays employing derivatives of the bioluminescent molecule aequorin, and have shown that detection of mucosal and serum antibodies is considerably more sensitive when detected by luminometry. luminometry is based upon counting photons of light via phototubes and is generally similar to scintillation spectrometry. current commercial luminometric technology employs a phototube which is most efficient for light ... | 1996 | 8621954 |
| specific uptake of intracranial horseradish peroxidase (hrp) by microglial cells in the goldfish. | intracranial injections of horseradish peroxidase (hrp) in the goldfish labeled a population of cells with many similarities to microglia. the fact that neither macroglia nor neurons appeared to be labeled by these injections supports this identification. the labeled cells responded to wallerian degeneration of the optic paths by accumulating in the optic terminal zones, a cellular behavior which strongly supports their identification as microglia. | 1996 | 8731163 |
| novel detection method of nitric oxide using horseradish peroxidase. | nitric oxide (no) readily makes corresponding complexes not only with ferrous iron but also with ferric iron. however, no-ferric complexes of many heme proteins were unstable, while horseradish peroxidase formed the very stable no-ferric porphyrin complex with a shift of the soret band of the absorption wavelength from 396.5 nm to 420.0 nm. the concentration of no in aqueous media could be monitored by measuring the absorption changes, and the detection limit was 10 nm. the simple procedure is c ... | 1996 | 9132178 |
| studies on the purification of peroxidase from horseradish roots using reverse micelles. | horseradish peroxidase (hrp) was successfully purified from horseradish roots by a two-stage reverse-micellar extraction from the dialyzed aqueous extract. the anionic surfactant aot dissolved in isooctane was used to produce the reverse-micellar phases. the narrow ph range at which hrp solubilization occurred was exploited to remove most of the contaminant proteins in the first forward extraction. in the second extraction stage, hrp was selectively solubilized and concentrated by using a volume ... | 1996 | 8882000 |
| characterization of a lectin from the leaves of great northern bean, phaseolus vulgaris l. | a novel lectin (gnll) was isolated from the leaves of the great northern bean, phaseolus vulgaris. gnll was purified by affinity chromatography on ovomucoid-sepharose 4b. gnll had a molecular mass of 135 kda on gel filtration and gave two bands on sds-polyacrylamide gel electrophoresis (page)(band a of 34.0 kda and band b of 34.2 kda). binding assay of horseradish peroxidase (hrp)-glycoproteins to the bands electroblotted onto polyvinylidene difluoride (pvdf) membrane showed that both bands coul ... | 1996 | 8829525 |
| metabolic activation of pcbs to quinones: reactivity toward nitrogen and sulfur nucleophiles and influence of superoxide dismutase. | polychlorinated biphenyls (pcbs) may undergo cytochrome p-450-catalyzed hydroxylations to form chlorinated dihydroxybiphenyl metabolites. when the hydroxyl groups are ortho or para to each other, oxidation to a quinone may be catalyzed by peroxidases present within the cell. in order to study the reactivity of pcb-derived quinones, selected chlorophenyl 1,2- and 1,4-benzoquinones were synthesized and characterized, including their reduction potentials against a saturated calomel electrode. two q ... | 2013 | 8728508 |
| evaluation of the gut mucosal barrier: evidence for increased antigen transfer in children with atopic eczema. | intestinal antigen handling determines subsequent immune response to the antigen. antigens are absorbed across epithelium along two functional pathways. the main pathway is degradative, which reduces the immunogenicity of the antigen. a minor pathway allows the transport of intact proteins, which is crucial for antigen-specific immune responses. the ussing chamber method allows the quantitative measurement of protein transfer across the intestinal mucosa. | 1996 | 8655895 |
| the spinal sympathetic preganglionic cell column in the puffer fish, takifugu niphobles. | little is known about the spinal sympathetic organization in teleosts. we examined the location of the sympathetic preganglionic neurons with horseradish peroxidase (hrp) labeling. after hrp application to the sympathetic trunk or celiac ganglion, labeled neurons were found just dorsal - dorsolateral to the central canal. they form a cell column (central autonomic nucleus) at the level of the posterior rootlet of the first spinal nerve to the third spinal nerve. hrp application to the sympatheti ... | 1996 | 8601286 |
| differential central projections of vestibular afferents in pigeons. | the question of whether a differential distribution of vestibular afferent information to central nuclear neurons is present in pigeons was studied using neural tracer compounds. discrete tracing of afferent fibers innervating the individual semicircular canal and otolith organs was produced by sectioning individual branches of the vestibular nerve that innervate the different receptor organs and applying crystals of horseradish peroxidase, or a horseradish peroxidase/cholera toxin mixture, or a ... | 1996 | 8867286 |
| the crystal structure of peanut peroxidase. | peroxidases catalyze a wide variety of peroxide-dependent oxidations. based on sequence alignments, heme peroxidases have been divided into three classes. crystal structures are available for peroxidases of classes i and ii, but until now no structure has been determined for class iii, the classical extracellular plant peroxidases. | 1996 | 8805539 |
| kinetics of the formation of p-670 and of the decay of compound iii of horseradish peroxidase. | the kinetics of the decay of compound iii of horseradish peroxidase formed from compound ii and excess hydrogen peroxide and of the formation of p-670 from this preparation were studied as a function of ph at 25 degrees c and constant ionic strength of 0.11. compound iii undergoes an irreversible formation of p-670 and a slow, spontaneous decay to ferriperoxidase via compound ii and the rate of compound iii decay is less than that of p-670 formation at all ph values. both reactions follow pseudo ... | 1996 | 8619615 |
| probing the active site residues in aromatic donor oxidation in horseradish peroxidase: involvement of an arginine and a tyrosine residue in aromatic donor binding. | the plausible role of arginine and tyrosine residues at the active side of horseradish peroxidase (hrp) in aromatic donor (guaiacol) oxidation was probed by chemical modification followed by characterization of the modified enzyme. the arginine-specific reagents phenylglyoxal (pgo), 2,3-butanedione and 1,2-cyclohexanedione all inactivated the enzyme, following pseudo-first-order kinetics with second-order rate contents of 24m(-1.)min(-1), 0.8m(-1.)min(-1) and 0.54m(-1.)min(-1) respectively. modi ... | 1996 | 8615798 |
| ultrastructural study of external cuneothalamic neurons and their synaptic relationships with primary afferents in the gerbil. | the present study examined the synaptic organization of external cuneothalamic neurons and their relationships with primary afferents in the gerbil external cuneate nucleus (ecn) following an injection of horseradish peroxidase (hrp) into the anterodorsal cap of the ventrobasal thalamus in conjunction with a simultaneous injection of hrp into the contralateral brachial and cervical nerve plexuses. the thalamus-projecting neurons have been shown to be confined to the intermediate portion of the c ... | 1996 | 8907355 |
| intertectal commissural projection in the lizard gallotia stehlini: origin and midline topography. | the retinotectal projection of reptiles is largely crossed. the intertectal commissure is an important pathway that interconnects directly the two sides of the optic tectum. the rostrocaudal topography of intertectal commissural fibers at the dorsal midplane was examined by means of the in vitro horseradish peroxidase (hrp) labelling technique in the lizard gallotia stehlini. unilateral large deposits of tracer in the optic tectum as well as smaller deposits restricted to one quadrant were used ... | 1996 | 8698893 |
| neuronal architecture of the dorsal nucleus (cochlear nucleus) of the frog, rana pipiens pipiens. | the neuronal architecture of the dorsal nucleus of the northern leopard frog (rana pipiens pipiens), which is a homolog of the cochlear nucleus of mammals and birds, was investigated. our study showed that the frog dorsal nucleus contains a number of morphologically distinct cell types that are discernible in terms of the cellular architecture as derived from nissl-stained material and in terms of the dendritic profile as revealed by horseradish peroxidase-filled single neurons. these cell types ... | 1996 | 8698890 |
| benzoylecgonine hydrazides: synthesis, coupling to horseradish peroxidase, and characterization of the conjugates. | benzoylecgonine-horseradish peroxidase conjugate (be-hrp) can be used as a diagnostic reagent for the detection of cocaine in illicit drug samples and in biological fluids. this paper describes the preparation and characterization of be-hrp. two hydrazide derivatives of benzoylecgonine, n-2-(tert-butyloxycarbonyl)benzoylecgonine hydrazide and mono(n-2'-benzoylecgoninoyl)adipic dihydrazide, were synthesized by carbodiimide-activated coupling of benzoylecgonine to n-2-(tert-butyloxycarbonyl) hydra ... | 2013 | 8983349 |
| protein patterning with a photoactivatable derivative of biotin. | a method is described for the covalent immobilization of macromolecules at defined location on polymer surfaces. a thin film of a photoactivatable analogue of biotin, n-(4-azido-2-nitrophenyl)-n'-(n-d-biotinyl-3-aminopropyl)-n'-methyl-1,3- propanediamine (photobiotin, in salt form) was dried onto polystyrene or nitrocellulose surfaces and then exposed to intense white light through a mask to yield patterns of biotin covalently bound to the polymers. the subsequent addition of avidin resulted in ... | 2013 | 8983347 |
| redox mediation in the peroxidase-catalyzed oxidation of aminopyrine: possible implications for drug-drug interactions. | many drugs, industrial pollutants, and other xenobiotics are known to be oxidized by peroxidases to potentially harmful free-radical intermediates. we have examined the possibility that certain compounds, acting as efficient peroxidase substrates, may stimulate the formation of reactive free radicals by acting as mediators of electron transfer reactions (redox mediators). to explore this hypothesis, we have investigated the interaction of two well-known peroxidase substrates, chlorpromazine and ... | 1996 | 8839052 |
| characterization of a new lectin of soybean vegetative tissues. | lectins are carbohydrate-binding proteins that occur widely among plants. lectins of plant vegetative tissues are less well characterized than those of seeds. previously, a protein of soybean (glycine max [l.] merr.) leaves was shown to possess properties similar to the seed lectin. here we show that the n-terminal amino acid sequence of this protein shares 63% identity with the seed lectin. immunoblot analysis indicated that the protein occurs in leaves, petioles, stems, and cotyledons of seedl ... | 1996 | 8819869 |
| anterograde axonal tracing with the subunit b of cholera toxin: a highly sensitive immunohistochemical protocol for revealing fine axonal morphology in adult and neonatal brains. | we report an improved immunohistochemical protocol for revealing anterograde axonal transport of the subunit b of cholera toxin (ctb) which stains axons and terminals in great detail, so that single axons can be followed over long distances and their arbors reconstructed in their entirety. our modifications enhance the quality of staining mainly by increasing the penetration of the primary antibody in the tissue. the protocol can be modified to allow combination in alternate sections with tetram ... | 1996 | 8815303 |
| distribution and subcellular localization of a growth inhibitory factor in hamster liver and its intracellular partner(s). | the subcellular, intralobular distributions and intracellular partner(s) of a factor which inhibits the proliferation of cell growth (hashimoto c. et al. (1994) biochim. biophys. acta 1221, 107-117) were determined in hamster livers, using a combination of immunological and biochemical techniques. the igg fraction from an antiserum raised against the growth inhibitory factor with 37 kda was shown to be highly specific for the antigen. the nuclear and cytosolic fractions demonstrated inhibitory e ... | 1996 | 8599609 |
| role of arginine 38 in horseradish peroxidase. a critical residue for substrate binding and catalysis. | the observed pseudo-first order rate constant for the reaction between a horseradish peroxidase (hrp) variant (r38l)hrpc* and hydrogen peroxide saturates at high peroxide concentrations (km = 11. 8 mm). the data are consistent with a two-step mechanism involving the formation of an hrp-h2o2 intermediate (k = 1.1 x 10(4) m-1 s-1) whose conversion to compound i is rate-limiting (k = 142 s-1) suggesting that arg-38 is not only involved in the cleavage of the o-o bond of peroxide but also has an imp ... | 1996 | 8626735 |
| distribution and synaptology of glossopharyngeal afferent nerve terminals in the nucleus of the solitary tract of the hamster. | the distribution and synaptology of the afferent fibers of the glossopharyngeal nerve (ixn) in the hamster were studied by using horseradish peroxidase (hrp) histochemistry visualized with light and electron microscopy. crystals of hrp were applied to the trunk of ixn in the vicinity of the petrosal ganglion. the densest ixn afferent label was distributed within the nucleus of the solitary tract (nst), just caudal to but overlapping with the area of termination of the facial nerve. labeled ixn f ... | 1996 | 8742302 |
| evidence for a free radical chain mechanism in the reaction between peroxidase and indole-3-acetic acid at neutral ph. | the oxidation of indole-3-acetic acid (iaa) catalyzed by horseradish peroxidase (hrp) in the absence of added h2o2 was studied at ph 7.4 using spectral and kinetic approaches. upon addition of a hundred-fold excess of iaa to hrp the native enzyme was rapidly transformed to compound ii (hrp-ii). hrp-ii was the predominant catalytic enzyme species during the steady state. no compound iii was observed. hrp-ii was slowly transformed to the stable inactive verdohemo-protein, p-670. a precursor of p-6 ... | 1996 | 17023361 |
| evidence for a slow tertiary relaxation in the reaction of tert-butyl isocyanide with horseradish peroxidase. | the kinetics of tert-butyl isocyanide binding to the heme protein horseradish peroxidase (hrp) at 22 degrees c was examined on all time scales, from minutes to picoseconds, in aqueous borate buffer at ph 9.08. unlike myoglobin (mb) or hemoglobin, hrp shows two bimolecular ligand binding processes. for comparison, binding of the same ligand with mb was measured under identical conditions. ligand entry into the protein from the solvent in a mixing experiment is extremely slow in hrp: the bimolecul ... | 1996 | 8634280 |
| immobilized glucose-6-phosphate dehydrogenase as a substrate for solubilized epidermal growth factor receptor tyrosine kinase. a convenient microtiter plate assay system. | based on our previously reported solution assay protocol, a solid-phase assay for the tyrosine kinase activity of the epidermal growth factor receptor has been developed. glucose-6-phosphate dehydrogenase, immobilized noncovalently on microtiter plates, was used as the substrate in the solid-phase assay. phosphorylation of the immobilized substrate takes place in the presence of atp and a solubilized epidermal growth factor receptor preparation. after washing off the soluble reaction mixture, th ... | 1996 | 9045597 |
| comparison of 5-hydroxy-2, 3-dihydrophthalazine-1, 4-dione and luminol as co-substrates for detection of horseradish peroxidase in enhanced chemiluminescent reactions. | the utility of 5-hydroxy-2, 3-dihydrophthalazine-1, 4-dione (hdp) as a co-substrate for the chemiluminescent detection of horseradish peroxidase was assessed. several substituted aryl boronic acid derivatives (4-phenyl, 4-iodo) acted as potent enhancers of the peroxidase catalyzed reaction. addition of chelating agents (edta) and surfactants (tween-20 and [poly (vinylbenzyl)tributylphosphonium chloride-poly (vinylbenzyl) trioctylphosphonium chloride copolymer]) modulated background light emissio ... | 1996 | 8926307 |
| rapid bright-field detection of oligonucleotide primed in situ (prins)-labeled dna in chromosome preparations and frozen tissue sections. | we describe a new application of a bright-field microscopic procedure for rapid enzyme cytochemical detection of repeated dna sequences in metaphase preparations and frozen tissue sections. various chromosome-specific oligonucleotide primers were used in up to three sequential primed in situ (prins) labeling reactions together with taq dna polymerase and biotin, digoxigenin and/or fluorescein isothiocyanate (fitc)-modified nucleotides. dna target sequences were localized simultaneously by the pr ... | 1996 | 8825152 |
| [influence of peripheral process branching in nerve of spinal ganglion on the primary afferent impulse]. | in order to observe the electrical and morphological characteristics of neurons in toad spinal ganglion (sg) preparation, microelectrode filled with 0.75% horseradish peroxidase (hrp) was used both for intracellular recording and for intracellular labelling. histological result showed that there were apparent branchings in peripheral process of a type cells. intra-axonal recording of the discharges of dorsal root fiber could be evoked by simultaneous stimulation of two separate fine bundles in s ... | 1996 | 8758687 |
| oscillatory nadh-oxidase activity of horseradish peroxidase. | | 1996 | 8674713 |
| a critical period for the specification of motor pools in the chick lumbosacral spinal cord. | when 3-4 segments of the chick lumbosacral neural tube are reversed in the anterior-posterior axis at stage 15 (embryonic day 2.5), the spinal cord develops with a reversed organization of motoneurons projecting to individual muscles in the limb (c. lance-jones and l. landmesser (1980) j. physiol. 302, 581-602). this finding indicated that motoneuron precursors or components of their local environment were specified with respect to target by stage 15. to identify the timing of this event, we hav ... | 1996 | 8625817 |
| distribution of synapses on two local auditory interneurones, on1 and on2, in the prothoracic ganglion of the cricket: relationships with gaba-immunoreactive neurones. | in the prothoracic ganglia of the cricket gryllus bimaculatus two local auditory interneurones, on1 and on2, were labelled for electron microscopy by intracellular injection of horseradish peroxidase following physiological characterisation. the neurones branch in the median ventral association centre and the root of nerve 5 on both sides of the ganglion. as they are very similar in shape and position they may share a common embryological origin. differences are found in the details of the fine ... | 1996 | 8593653 |
| synaptic input to cochlear nucleus dendrites that receive medial olivocochlear synapses. | axons of olivocochlear neurons originate in the superior olivary complex and project to the cochlea. along their course, medial olivocochlear axons give off branches to the cochlear nucleus. we labeled these branches with horseradish peroxidase and used electron microscopy to determine their target dendrites. target dendrites were of two classes: "large" dendrites and "varicose" dendrites. using serial sections, we reconstructed the dendrites and, in addition to the labeled olivocochlear input, ... | 1996 | 8821439 |
| spectral properties of environmentally sensitive probes associated with horseradish peroxidase. | the environmentally sensitive fluorescent probes 6-propionyl-2-(n,n-dimethylamino)naphthalene (prodan) and 2'-(n,n-dimethylamino)-6-naphthoyl-4-trans-cyclohexanioc acid (danca) form complexes with the heme binding site of apohorseradish peroxidase. the dissociation constants of the prodan and danca complexes were determined from anisotropy titration data to be approximately 8.7 x 10(-5) and 3.3 x 10(-4) m, respectively. from comparison of the steady state fluorescence spectra of prodan and danca ... | 1996 | 8547280 |
| pre- and postmetamorphic organization of the vestibular nuclear complex in the turbot examined by retrograde tracer substances. | during metamorphosis of flatfish larvae, eye migration leads to a 90 degrees misalignment of the visual and vestibular frames of reference. in order to maintain vestibular eye stabilization, the vestibulo-ocular (v-o) pathways have to be radically reorganized. here, we have examined the vestibular projections in turbot larvae and juveniles by means of conventional neurohistological techniques using horseradish peroxidase and fluorescent dextranamines as tracers. we have found that the vestibular ... | 1996 | 8821454 |
| increased serotonin in the developing superior colliculus does not alter the number or distribution of retinotectal ganglion cells. | administration of a single subcutaneous dose of 5,7-dihydroxytryptamine (5,7-dht) to newborn hamsters results in a significant increase in the density of serotoninergic (5-ht) fibers in the superficial layers of the superior colliculus (sc) and marked abnormalities in both the crossed and uncrossed retinotectal projections when these animals reach adulthood (r. rhoades, c. bennett-clarke, r. lane, m. leslie, and r. mooney, 1993, j. comp. neurol. 334:397-409). the present study was undertaken to ... | 1996 | 8820874 |
| development of electrophoretic conditions for the characterization of protein glycoforms by capillary electrophoresis-electrospray mass spectrometry. | a capillary electrophoresis (ce) method using acidic buffers and capillaries coated with polybrene, a cationic polymer has been developed for the separation of glycoproteins and glycopeptides. electrophoretic conditions have been optimized to provide resolution of individual glycoforms observed for different glycoprotein preparations. these conditions were found to be entirely compatible with the operation of electrospray mass spectrometry (esms), which facilitated the assignments of possible ca ... | 1996 | 8601204 |
| rates of reaction of indoleacetic acids with horseradish peroxidase compound i and their dependence on the redox potentials. | the rates of reaction of seven indole-3-acetic acid derivatives with horseradish peroxidase compound 1 at ph 5 were measured by stopped flow, and the reduction potentials and pka of their radical cations were determined by pulse radiolysis. reasonable correlation of these properties with hammett substituent parameters was found, but not with brown-okamoto (theta +) parameters. the rates of reaction with compound i correlate well with the reduction potentials under the same conditions, with rates ... | 1996 | 8555162 |
| fabrication and features of a methylene green-mediating sensor for hydrogen peroxide based on regenerated silk fibroin as immobilization matrix for peroxidase. | regenerated silk fibroin prepared from waste silk was employed as immobilization matrix for peroxidase and the structures of the blend membranes of regenerated silk fibroin and peroxidase were first investigated with ir and scanning electron microscopy. there was intermolecular interaction between peroxidase and regenerated silk fibroin in the immiscible state. cyclic voltammetry and constant applied potential measurement showed that methylene green efficiently mediated electron transfer from ox ... | 1996 | 18966470 |
| simultaneous identification of a specific gene protein product and transcript using combined immunocytochemistry and in situ hybridization with non-radioactive probes. | simultaneous identification of messenger rna (mrna) and proteins in the same cells or tissues is a valuable tool to help the cell biologist evaluate the cell secretory cycle. some cells may produce the mrna and delay the production of the proteins. alternatively, the proteins may be rapidly secreted. other cells may produce both in sequence within the same time frame. because of this difference, some cells can only be identified by their mrna product. others may have both products. this presenta ... | 1996 | 9601526 |
| the fine structure of the lateral geniculate complex in the frog rana esculenta. | the lateral geniculate complex of the frog is composed of two neuropil areas, the neuropil of bellonci and the corpus geniculatum thalamicum that receive axons of retinal origin. the nucleus of bellonci, and some other cell groups project dendrites into the neuropil. in normal animals three types of axon terminals (a1, a2, a3), light and dark dendrites, dendritic appendages and presynaptic dendrites were distinguished as components of the lateral geniculate circuitry. using horseradish peroxidas ... | 1996 | 9123998 |
| thymic nurse cells: entry of exogenous horseradish peroxidase via a transcytotic route. | in order to address the question whether thymocytes inside thymic nurse cells (tncs) are secluded against exogenous proteins, tncs were isolated and kept in the presence of horseradish peroxidase. the distribution of horseradish peroxidase reaction product (hrp) within the tncs was studied by light (lm) and electron microscopy (em). stained and unstained tncs could be distinguished by lm. at the em level, stained tncs had a widened lumen and hrp lined the luminal surfaces. in unstained tncs the ... | 1996 | 9096739 |