PMID(sorted ascending)
[microenvironment of enzymes as 1 of the factors determining enzyme stability. stabilization of soluble and immobilized horseradish peroxidase]. 1975223
heme-linked protonation of hcn, co, no and o2 complexes of reduced horseradish peroxidases. 1975971
oxidase-peroxidase enzymes of datura innoxia. oxidation of formylphenylacetic acid ethyl enzyme system from datura innoxia roots oxidizing formylphenylacetic acid ethyl ester was purified 38-fold by conventional methods such as (nh4)2so4 fractionation, negative adsorption on alumina cy gel and chromatography on deae-cellulose. the purified enzyme was shown to catalyse the stoicheiometric oxidation of formylphenylacetic acid ethyl ester to benzoylformic acid ethyl ester and formic acid, utilizing molecular o2. substrate analogues such as phenylacetaldehyde and phenylpyruvate were ...1975997
[effect of prosthetic group of horseradish peroxidase on enzyme stability].constants of inactivation rate of horseradish peroxidase (hrp) apo-hrp and apo-hrp-protoporphyrin (pp) are estimated at the ph range 2.8-12.8 and 25 degrees c. two ionogenic groups (acid and alkaline) are detected on cases of hrp and apo-hrp, which are responsible for stable hrp conformation. hrp stability within the ph range 5-10 exceeded 30 times that of apo-hrp, while the stability apo-hrp-pp complex is similar to that of apo-hrp. the data obtained show that formation of complex of apo-hrp wi ...20071105
[kinetics and mechanism of action of horseradish peroxidase in the reaction of dioxyfumaric acid oxidation with atmospheric oxygen].quantitative kinetic data are given on the oxidation reaction of dioxyfumaric acid (dfa) with atmospheric oxygen in the presence of horseradish peroxidase (hrp) depending on ph. activation constants of oxidation with hydrogen peroxide and mn ions are determined at ph 3.0. autocatalytic character of fra oxidation is shown to be due to the formation of h2o2 and other hydro peroxide-type compounds in the reaction, hrp convertions in the dfa--o2 system are studied using spectrophotometry. a mechanis ...20131108
hepatic nucleases. extrahepatic origin and association of neutral liver ribonuclease with the large granule fraction of rat liver, the density distribution of inhibitor-sensitive neutral ribonuclease is similar to that for acid hydrolases and its density distribution is similarly modified by triton wr-1339 accumulation in lysosomes. particulate neutral ribonuclease is latent; the enzyme is unmasked by very low digitonin concentrations or hypoosmotic shock. these observations demonstrate that the bulk of liver neutral ribonuclease is associated with the lysosomal system. in view of ...19751273
heme-linked proton dissociation of carbon monoxide complexes of myoglobin and was found from spectrophotometric titration and proton balance measurement that the pka value of a heme-linked protonation group of horseradish ferro-peroxidase c (donor:h2o2 oxidoreductase, ec shifted from 7.25 to 8.25 upon combination with co. the spectrophotometric titration experiment with myoglobin also revealed the presence of a heme-linked protonation group, the pka value being 5.57 in myoglobin and 5.67 in the co-myoglobin complex. it was concluded that the distinct shift of ...19765132
mechanisms of electron transfer from sulfite to horseradish peroxidase-hydroperoxide compounds.using a rapid-scan spectrophotometer equipped with a stopped-flow apparatus, reactions of sulfite with compounds i and ii of two horseradish peroxidase isoenzymes a and c were investigated. the direct two-electron reduction of peroxidase compound i by sulfite occurred at acidic ph but the mechanism gradually changed to the two-step reduction with the intermediate formation of compound ii as the ph increased. the ph at which the one- and two-electron changes occurred at the same speed was 4.5 for ...19768081
comparison of function of the distal base between myoglobin and peroxidase.the heme-linked protonation of a ferrous horseradish peroxidase is assigned to a distal amino acid residue. the conclusion is drawn from analyses of reactions that involve the protonation. unfortunately it is difficult to apply it to the myoglobin case because no reaction has been found which is coupled with the protonation of the distal histidine. it is therefore of special interest to note that the pk value of 5.7 has been assigned to the distal histidine of metmyoglobin from binding kinetics ...19768964
the kinetics of formation of horseradish peroxidase compound i by reaction with peroxobenzoic acids. ph and peroxo acid substituent effects.1. the kinetics of formation of horseradish peroxidase compound i were studied by using peroxobenzoic acid and ten substituted peroxobenzoic acids as substrates. kinetic data for the formation of compound i with h2o2 and for the reaction of deuteroferrihaem with h2o2 and peroxobenzoic acids, to form a peroxidatically active intermediate, are included for comparison. 2. the observed second-order rate constants for the formation of compound i with peroxobenzoic acids decrease with increasing ph, i ...19769067
oxidation of p-cresol by horseradish peroxidase compound i.rate constants for the reaction between horseradish peroxidase compound i and p-cresol have been determined at several values of ph between 2.98 and 10.81. these rate constants were used to construct a log (rate) versus ph profile from which it is readily seen that the most reactive form of the enzyme is its most basic form within this ph range so that base catalysis is occurring. at the maximum rate a second order rate constant of (5.1 +/- 0.3) x 10(-7) m-1 s-1 at 25 degrees is obtained. the ac ...19769411
stoichiometry of the reaction between horseradish peroxidase and p-cresol.over a wide range of ph horseradish peroxidase compound i can be reduced quantitatively via compound ii to the native enzyme by only 1 molar equivalent of p-cresol. since 2 molar equivalents of electrons are required for the single turnover of the enzymatic cycle, p-cresol behaves as a 2-electron reductant. with p-cresol and compound i in a 1:1 ratio compound ii and p-methylphenoxy radicals are obtained in the transient state. compound ii is then reduced to the native enzyme. a possible explanat ...19769412
[catalytic properties and stability of horseradish peroxidase immobilized in polyacrylamide gel].effect of polyacrylamide (paa) gel on properties of horseradish peroxidase, immobilized by means of the incorporation into paa gel is studied. catalytic properties of immobilized enzyme are studied. km value and ph-dependency of the enzyme activity are found to be close to those of soluble enzyme, kcat value is 3 times lower at ph 7.0. ph-stability of immobilized peroxidase at 20 degrees c and thermostability of soluble and immobilized peroxidases at ph 7.0 within the temperature range from 20 t ...197610016
compound x. an intermediate in enzymatic halogenation.previous studies have shown that chlorite serves as a halogenation substrate for horseradish peroxidase. in its substrate role, chlorite serves both as a halogen donor and as a source of oxidizing equivalents in the chlorination reaction. we now show that a new spectral intermediate, which we have termed compound x, can be detected as the initial product of the reaction of chlorite with horseradish peroxidase. the reaction of chlorite with horseradish peroxidase to form compound x is a relativel ...197610296
the shapes of sensory and motor neurones and the distribution of their synapses in ganglia of the leech: a study using intracellular injection of horseradish peroxidase. 197612513
absorption of free and antibody-conjugated horseradish peroxidase to fixed glial cells in tissue culture, a possible source of error in immunohistochemistry.incubation of cellular preparations with antibody-conjugated peroxidase result in a very strong unspecific staining, for one electropolar binding of the basic enzymic protein with the cell structures. in immunohistochemical practice, it may represent an evil as import as when dealing with immunofluorescence techniques. this background can to a great extent be avoided by rinsing the preparations in buffer at ph = 6.2.197612639
effect of cyanide on nadph oxidation by granules from human polymorphonuclear leukocytes.cyanide has been shown to stimulate both oxygen uptake and hexose monophosphate shunt activity in phagocytizing human polymorphonuclear leukocytes. it also stimulates the oxidation of nadph by a particulate fraction derived from phagocytizing cells. this stimulation of nadph oxidase is not observed in the presence of exogenous mn2+. studies with purified enzymes have shown that cn- also stimulates nadph oxidation by horseradish peroxidase or lactoperoxidase, suggesting that the respiratory burst ...197713879
purification of bovine thyroid peroxidase.trypsin-solubilized peroxidase activity from beef subcellular particles was resolved by deae-cellulose chromatography into 5 fractions, which contained enzymatically active components that ranged in molecular size from 73,000 to 340,000 daltons. the most active fraction (mol wt, 92,000 by gel filtration) was further purified (59,000-fold overall) by chromatography on hydroxylapatite. this highly purified peroxidase preparation had an absorbance purity ratio (a410:a280) of 0.55 and oxidized iodid ...197715822
magnetic circular dichroism studies on acid and alkaline forms of horseradish peroxidase.the heme vicinities of the acid and alkaline forms of native (fd(iii)) horseradish peroxidase were investigated in terms of the magnetic circular dichroism (mcd) spectroscopy. the mcd spectrum of the acid form of native horseradish peroxidase was characteristic of a ferric high spin heme group. the resemblance in the mcd spectrum between the acid form and acetato-iron (iii)protoporphyrin ix dimethyl ester suggests that the heme iron of the acid form has the electronic structure similar to that i ...197719085
cobalt-substituted horseradish peroxidase.horseradish peroxidase can be reconstituted with cobalt porphyrin to give a cobaltic holoenzyme having physicochemical properties quite similar to those of the native ferric protein. the cobaltic protein (co3+hrp) can be reduced to the cobaltous form (cohrp), the analogue of ferroperoxidase and the reduced cobalt protein can bind o2 to form an analogue of oxyferroperoxidase (compound iii). since both the cohrp and oxy-cohrp are epr-visible, the cobalt has been used to probe the nature of the hem ...199619470
the conjugation of testosterone with horseradish peroxidase and a sensitive enzyme assay for the conjugate.the formation of a horseradish peroxidase-testosterone conjugate for the enzyme-linked immunoassay of testosterone was investigated, using tritiated testosterone to follow the reaction. the formation of testosterone-3-(carboxymethyl) oxime-peroxidase by the mixed anhydride method was found to give a conjugate of high enzymatic activity and with three molecules of testosterone per molecule of peroxidase. the optimum conditions for the assay of peroxidase activity were studied and an assay capable ...199819860
[thermal inactivation and storage behavior of technologically important enzymes. i. horseradish and spinach peroxidase].the thermal inactivation and storage behaviour for horseradish and spinach peroxidases were investigated in defined systems, in spinach also within its natural environment. the inactivation curves of either enzyme show a sharp bend which is clearly visible at low, but not at higher temperatures. the d-values were taken from the inactivation curves. z-values resulting from the d-values were 25.5 degrees c for horseradish peroxidase, 13 degrees c for isolated peroxidase and 18 degrees c for peroxi ...197719887
the role of cytochrome p-450 in the hydroperoxide-catalyzed oxidation of alcohols by rat-liver microsomes.the organic hydroperoxide cumene hydroperoxide is capable of oxidizing ethanol to acetaldehyde in the presence of either catalase, purified cytochrome p-450 or rat liver microsomes. other hemoproteins like horseradish peroxidase, cytochrome c or hemoglobin were ineffective. in addition to ethanol, higher alcohols like 1-propanol, 1-butanol and 1-pentanol are also oxidized to their corresponding aldehydes to a lesser extent. other organic hydroxyperoxides will replace cumene hydroperoxide in oxid ...197720305
nuclear magnetic resonance studies of hemoproteins. acid-alkaline transition, ligand binding characteristics, and structure of the heme environments in horseradish peroxidase. 197720945
[kinetic study of o-dianisidine oxidation by hydrogen peroxide in the presence of horseradish peroxidase].a kinetic study of o-dianisidine oxidation by hydrogen peroxide in the presence of horseradish peroxidase within the ph range of 3.7-9.0 has been carried out. it was shown that the reaction of o-dianisidine peroxidase oxidation obeys the michaelis--menten kinetics; the kcat and km values within the ph range used were determined. the optimum of peroxidase catalytic activity during o-dianisidine oxidation was observed at ph 5.0-6.0. the kinetic pattern of the reaction is discussed. it was demonstr ...197720989
adsorption of horseradish peroxidase, ovomucoid and anti-immunoglobulin to colloidal gold for the indirect detection of concanavalin a, wheat germ agglutinin and goat anti-human immunoglobulin g on cell surfaces at the electron microscopic level: a new method, theory and application.a method is described for the adsorption of selected macromolecules to colloidal gold which is then used as an electron dense marker for the indirect detection of specific cell surface molecules. membrane bound concanavalin a, which binds specific sugars on horseradish peroxidase, and wheat germ agglutinin, which binds specific sugars on ovomucoid are detected indirectly with gold labeled horseradish peroxidase and ovomucoid, respectively. goat anti-human igm on blood lymphocytes is detected wit ...197721217
tetramethyl benzidine for horseradish peroxidase neurohistochemistry: a non-carcinogenic blue reaction product with superior sensitivity for visualizing neural afferents and efferents.tetramethyl benzidine (tmb) is a presumptively non-carcinogenic chromogen which yields a blue reaction-product at sites of horseradish peroxidase activity. sixty-six distinct procedures were performed in rats and monkeys in order to determine the optimal incubation parameters for tmb. as a result, a procedure is recommended whose sensitivity greatly surpasses that of a previously described benzidine dihydrochloride method. indeed, the sensitivity of this new method in demonstrating retrograde tr ...197824068
kinetic analysis of the acid-alkaline conversion of horseradish peroxidases.the nature of the acid-alkaline conversion of horseradish peroxidases was studied by measuring four rate constants in reactions, e + h+ (k1) in equilibrium (k2) eh+ and e + h2o (k3) in equilibrium (k4) eh+ + oh-, where eh+ and e denote the acid and alkaline forms of the enzymes. the values of k1, (k2 + k3), and k4 were obtained by measuring the relaxation rates of the acid leads to alkaline and alkaline leads to acid conversions by means of th ph jump method with a stopped-flow apparatus. the va ...197824465
effect of beta-lapachone on hydrogen peroxide production in trypanosoma cruzi.beta-lapachone, an antimicrobial agent, markedly increase the generation of h2o2 in intact trypanosoma cruzi epimastigotes (y strain). increase in h2o2 was determined by the horseradish peroxidase-h2o2 compound ii formation as well as by a cytochemical technique.197824995
a new reaction scheme for the alkaline isomerization of horseradish peroxidase. 199725085
enzymatic determination of blood ethanol, with amperometric measurement of rate of oxygen depletion.a rapid electrochemical measurement of blood ethanol is proposed. alcohol is oxidized by nad+ in the presence of alcohol dehydrogenase; and the nadh produced is aerobically oxidized by horseradish peroxidase. the rate of depletion of buffer-carried oxygen, which is directly proportional to the alcohol concentration in the sample, is amperometrically monitored with a membrane oxygen-sensing electrode. only a 5-microliter sample of whole blood is required, with no deproteinization, incubation, ext ...199725144
magnetic circular dichroism studies of myoglobin, hemoglobin and peroxidase at room and low temperatures. ferrous high spin derivatives.the magnetic circular dichroism spectra (mcd) recorded for the visible and near-uv regions of high-spin ferrous derivatives of myoglobin, hemoglobin, hemoglobin dimers and isolated chains as well as of horseradish peroxidase at ph 6.8 and 11.4 have been compared at the room and liquid nitrogen temperatures. the mcd of the q00- and qv-bands have been shown to be sensitive to structural differences in the heme environment of these hemoproteins. the room temperature visible mcd of native hemoglobin ...199925682
[effect of n-alkylimidazoles on oxidation of o-dianizidine catalyzed by horseradish peroxidase].effect of a number of n-alkylimidazoles (from n-methyl to n-octylimidazole) on peroxidase oxidation of o-dianizidine at ph 8.0 is studied. alkylimidazoles studied are found to activate the reaction under given conditions, the activation type being non-competitive ka and (alpha) values are similar for all the activators, which suggests a similar mechanism of their action. similar ka values suppose an insignificant role of hydrophobic interactions in the binding of n-alkylimidazoles with the enzym ...197826428
[kinetics and mechanism of nucleophilic effect on the oxidation of o-dianisidine catalyzed by horseradish peroxidase].the effects of benzimidazole and 4-nitroimidazole on the reaction of o-dianisidine peroxidase oxidation within the ph range of 3.7--9.0 were studied. both substituted imidazoles activate the reaction at less than 0.6. in the presence of 4-nitroimidazole the activation is non-competitive, whereas in the presence of benzimidazole it is of a mixed type, which is close to the non-competitive one. the kinetic parameters (kacat, alpha, ka) for the reaction activated by both imidazoles were determined. ...197827245
leghemoglobin. low temperature optical spectra of acid and alkaline forms of leghemoglobin(iv). configuration of the heme.leghemoglobin(iv), the derivative of leghemoglobin at the formal oxidation state iv, when cooled to liquid nitrogen temperature exhibits radically different spectra at acid and alkaline ph. the acid and alkaline forms are freely interconvertible. the optical spectrum of the acid form is closely similar to optical spectra of the red higher oxidation states of horseradish and cytochrome c peroxidases, showing that the configuration of the heme iron is the same throughout this family of compounds. ...197827520
nuclear magnetic resonance studies of high-spin ferric hemoproteins.220 mhz proton fourier transform (ft) nmr with quadrature phase detection (qpd) technique is applied to observe largely hyperfine-shifted signals of various hemoproteins and hemoenzymes in ferric high-spin state. the binding of f-, ocn-, scn-, and ch3oh to the ferric heme iron in high-spin state in various hemoproteins has been studied by the use of ft/qpd technique at 220 mhz. the binding of formate ion to metmyoglobin (metmb) has also been studied. the spectrum of the formate complex was compa ...197827954
analysis of acid-base properties of peroxidase and myoglobin.two heme-linked groups of horseradish peroxidases, characterized by pka = 5.8 (isoenzyme a) and 7.3 (isoenzyme c), are believed to be distal amino acid residues and, judging by their acid-base properties in various derivatives, influence the functions of these isoenzymes. in contrast, in myoglobin ionization of the distal histidine does not influence its reactivity. accordingly, we conclude that the interaction of the distal base with a 6th ligand is weak in myoglobin but very strong in peroxida ...197827955
concanavalin a receptors on the cell membrane of trypanosoma cruzi.epimastigotes and trypomastigotes of t. cruzi obtained from acellular culture as well as bloodstream trypomastigotes agglutinate with concanavalin a (con a). con a-binding sites were also localized on the cell membrane by using the con a-horseradish peroxidase-diaminobenzidine method. passage of epimastigotes and trypomastigotes from acellular culture through deae-cellulose column did not affect con a-binding sites as detected by agglutination and electron miscroscopy.197828652
[chemical modification of epsilon-amino lysine groups in horseradish peroxidase. its effect on catalytic properties and spatial structure of the enzyme].effect of chemical modification of horseradish peroxidase lysine epsilon-amino groups by propionic, butyric, valeric, succinic anhydrides and trinitrobenzolsulfonic acid (tnbs) on catalytic properties of the enzyme is investigated. all the preparations of modified peroxidase have 100% peroxidase activity for o-dianizidine at ph 7.0, which indicates the absence of lysine epsilon-amino group in the enzyme active site. ph-dependencies of modified peroxidase relative activity are studied; modificati ...200129674
structural correlates of recurrent collateral interneurons producing both electrical and chemical inhibitions of the mauthner cell.intracellular injections of horseradish peroxidase provided a basis for morphological identification of inhibitory interneurons belonging to the recurrent collateral network of the mauthner cell. their axons dilate to form unusually large bulbs surrounding the axon cap. the morphological appearance of these bulbs as well as intracellular recordings at their level indicate that they behave as nodes and serve as a final source of current for electrical inhibition of the mauthner cell. the axon of ...197830093
proton nuclear magnetic resonance studies of compounds i and ii of horseradish peroxidase. 197830456
heme-linked ionization in compounds i and ii of horseradish peroxidases a2 and c. 200131136
[structure and function of horseradish peroxidase]. 197831196
reaction of horseradish peroxidase with azide and some implications for the heme environmental structure. nmr and kinetic studies.the azide complex of horseradish peroxidase was studied by high resolution 1h and 15n nmr spectroscopy and by the temperature-jump method. the heme peripheral methyl proton peaks and the ligand 15n resonance were resolved to show that binding of azide by horseradish peroxidase occurs only in acidic solution below ph 6.5. it was also found that the chemical exchange rate of azide with the ferric enzyme was much faster on the 1h and 15n nmr time scale. this was further substantiated by kinetics of ...197831922
a kinetic study of the reaction between glutaraldehyde and horseradish peroxidase.horseradish peroxidase was reacted with glutaraldehyde under various reaction conditions. the reaction product was, in a second step, bound covalently to aminohexyl groups attached to sepharose particles. the influence of ph, time and the concentration ratio of enzyme:glutaraldehyde on the reaction was evaluated. a first step reaction with 100-fold molar excess of glutaraldehyde to horseradish peroxidase at ph 9.5 for 2 hr at room temperature results in a high yield of conjugated enzyme with wel ...199932212
[chemical modification of lysine epsilon-nh2-groups in horseradish peroxidase. its effect on enzyme stability. temperature dependence of thermo-inactivation constants for native and modified peroxidase].thermostability of horseradish peroxidase modified by acetic, propionic, butyric, valeric and succinic anhydrides and trinitrobenzolsulfonic acid (tnbs) is studied within the temperature range of 56-80 degrees c. acylation of 4 amino groups and arylation of 3 amino groups with tnbs are found to stabilize the enzyme, while modification of 6 groups decreases the enzyme stability. chemical modification of peroxidase does not change its ph-dependence with respect to enzyme thermostability. thermodyn ...197832926
[horseradish peroxidase: a study of the kinetics and the determination of optimal reaction conditions, using hydrogen peroxide and 2,2'-azinobis 3-ethylbenzthiazoline-6-sulfonic acid (abts) as substrates (author's transl)].the reaction of the two substrates hydrogen peroxide and abts with horseradish peroxidase was studied kinetically. enzyme activity was determined as a function of substrate concentration and ph. michaelis constants were determined for the two substrates at various ph values. it was found that the affinity of the enzyme for abts decreases with increasing ph, and that with higher abts concentrations the ph optima of the reaction are shifted towards neutrality. maximal rate is reached at ph 4.2 wit ...197933227
oxidation of horseradish peroxidase compound ii to compound the reaction between equimolar amounts of horseradish peroxidase and chlorite, the native enzyme is oxidized directly to compound ii (hewson, w.d., and hager, l.p. (1979) j. biol. chem. 254, 3175-3181). at acidic ph but not at alkaline values, this initial reaction is followed by oxidation of compound ii to compound i. the highly ph-dependent chemistry of compound ii can be readily demonstrated by the reduction of compound i, with ferrocyanide at acidic, neutral, and alkaline ph values. titra ...197934616
horseradish peroxidase. xxxii. ph dependence of the oxidation of l-(-)-tyrosine by compound i.the rate of oxidation of l-(-)-tyrosine by horseradish peroxidase compound 1 has been studied as a function of ph at 25 degrees c and ionic strength 0.11. over the ph range of 3.20--11.23 major effects of three ionizations were observed. the pka values of the phenolic (pka = 10.10) and amino (pka = 9.21) dissociations of tyrosine and a single enzyme ionization (pka = 5.42) were determined from nonlinear least squares analysis of the log rate versus ph profile. it was noted that the less acidic f ...197835272
resonance raman investigations of chloroperoxidase, horseradish peroxidase, and cytochrome c using soret band laser excitation.resonance raman spectra of the heme protein chloroperoxidase in its native and reduced forms and complexed with various small ions are obtained by using laser excitation in the soret region (350-450 nm). additionally, raman spectra of horseradish peroxidase, cytochrome p-450cam, and cytochrome c, taken with soret excitation, are presented and discussed. the data support previous findings that indicate a strong analogy between the active site environments of chloroperoxidase and cytochrome p-450c ...197936129
electron paramagnetic resonance analyses of horseradish peroxidase in situ and after purification. 197937888
amino acid sequence studies of horseradish peroxidase. amino and carboxyl termini, cyanogen bromide and tryptic fragments, the complete sequence, and some structural characteristics of horseradish peroxidase c.horseradish peroxidase c dominates quantitatively among the isoperoxidases of horseradish root and has an isoelectric point close to 9. it consists of a hemin prosthetic group, 2 ca2+ and 308 amino acid residues, including 4 disulfide bridges, in a single polypeptide chain that carries 8 neutral carbohydrate side-chains. the molecular weight of the polypeptide chain is 33890. assuming an average carbohydrate composition of (glcnac)2, man3, fuc, xyl for each carbohydrate chain, the molecular weig ...199638113
immunocytochemical localization of neuronal antigens: tyrosine hydroxylase, substance p, [met5]-enkephalin.neuronal antigens can be demonstrated histologically by numerous direct and indirect immunocytochemical techniques in which a specific antibody is identified by a marker compound such as fluorescein isothiocyanate, ferritin, or horseradish peroxidase. one of the more sensitive methods for the light and electron microscopic localizations of antigens in sections of tissue is the peroxidase-antiperoxidase (pap) technique. the experimental procedures and the results obtained using this technique for ...197939006
the oxidation-reduction potentials of compound i/compound ii and compound ii/ferric couples of horseradish peroxidases a2 and c.the reversibility of the stepwise reduction of compound i to the ferric state via compound ii was confirmed in horseradish peroxidases a2 and c. the values of e'o (compound i/compound ii) and e'o (compound ii/ferric) were measured from equilibrium data coupled with the k2ircl6-k3ircl6 system in a narrow region of ph near 6.3. the ferric enzymes were also oxidized by ferricyanide to compound ii at alkaline ph and the values of e'o (compound ii/ferric) were measured from the equilibrium data. the ...197939073
freeze-fracture studies of frog neuromuscular junctions during intense release of neurotransmitter. ii. effects of electrical stimulation and high potassium.frog cutaneous pectoris nerve muscle preparations were studied by the freeze-fracture technique under the following conditions: (a) during repetitive indirect stimulation for 20 min, 10/s; (b) during recovery from this stimulation; and (c) during treatment with 20 mm k+. indirect stimulation causes numerous dimples or protuberances to appear on the presynaptic membrane of nerve terminal, and most are located near the active zones. deep infoldings of the axolemma often develop between the active ...199639080
chemical modification of the epsilon-amino groups of lysine residues in horseradish peroxidase and its effect on the catalytic properties and thermostability of the enzyme.chemical modification of horseradish peroxidase (donor:hydrogen-peroxide oxidoreductase, ec (isoenzyme c) by anhydrides of mono- and dicarboxylic acids and picryl sulfonic acid has been performed. the effect of the modification on the catalytic activity, absorption and circular dichroism spectra of peroxidase has been studied. rate constants of irreversible thermoinactivation (kin) for the native and modified peroxidase at 56--80 degrees c have been measured. the effective values of th ...197939612
postnatal rat sympathetic neurons in culture. i. a comparison with embryonic neurons.1. a morphological and physiological comparison was made between embryonically and postnatally derived superior cervical ganglion neurons (scgn) grown in dissociated cell culture. it was found that while morphologically distinct, the physiological properties of the postnatal neurons were the same as their embryonic counterparts. 2. intracellular injection of horseradish peroxidase (hpr) demonstrated that scgn from any age of animal elaborated two basic types of processes, although the pattern of ...197939983
chemical modification of horseradish peroxidase. preparation and characterization of tracer enzymes with different isoelectric points.horseradish peroxidase (hrp), a plant glycoprotein with a molecular weight of 40,000 d and a molecular radius (ae) of 30 a, has been modified chemically to prepare tracer molecules with different molecular charge. modification of free carboxyl groups on the enzyme is achieved by carbodiimide activation and subsequent reaction of activated carboxyl groups with a nucleophile; uncharged groups or radicals containing additional positively charged moieties are introduced into the protein molecule res ...197941873
a spin label study of horseradish peroxidase.the topography of the active sites of native horseradish peroxidase and manganic horseradish peroxidase has been studied with the aid of a spin-labeled analog of benzhydroxamic acid (n-(1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxy)-p-aminobenzhydroxamic acid). the optical spectra of complexes between the spin-labeled analog of benzhydroxamic acid and fe3+ or mn3+ horseradish peroxidase resembled the spectra of the corresponding enzyme complexes with benzhydroxamic acid. electron spin resonance ...197944680
distribution of immune deposits in the skin of reversed passive arthus reaction using horseradish peroxidase as antigen. 197645717
junctional complexes in the preimplantation rabbit embryo.the morphology and development of junctional complexes between blastomeres of the preimplantation rabbit embryo were investigated using several approaches. electron microscopic examination of embryos stained en bloc with uranyl acetate, and the study of junction permeability using horseradish peroxidase and lanthanum nitrate provided information on structure, intermembrane spacing and permeability of the junctional complexes. in addition, the freeze fracture technique was used with day 5 and day ...197545878
localization of immunoreactive androgen in testicular tissue.immunohistochemical localization of androgen in the testes of both rat and squirrel monkey has been performed using an antiserum specific to testosterone and certain related androgens. the bound antibodies were visualized by coupling with antigammaglobulin labeled either with fluorescein isothiocyanate or with a horseradish peroxidase-diaminobenzidine technique. the highest concentration of androgen was found in the interstitial tissue but a significant amount was also present in the seminiferou ...197545910
thalamic afferents to areas 17, 18 and 19 of cat cortex traced with horseradish peroxidase. 197546157
retrograde axonal transport of horseradish peroxidase in sensory nerves and ganglion cells of the rat. 197546159
retrograde intraaxonal transport of horseradish peroxidase in retinal ganglion cells of the chick. 197546164
the orthograde transport of horseradish peroxidase in the visual system. 197546168
a comparison of anterograde and retrograde axonal transport of horseradish peroxidase in the connections of the mammillary nuclei in the rat. 197546171
electron microscopic observations of horseradish peroxidase transported from the caudoputamen to the substantia nigra in the rat: possible involvement of the agranular reticulum.the intracellular distribution of horeseradish peroxidase (hrp) transported intraaxonally from the caudoputaminal complex to the substantia nigra has been examined with the electron microscope. the reciprocal axonal connections between the caudoputamen and the substantia nigra permitted observation not only of hrp transported retrogradely from axons and axon terminals in the caudoputamen to the cell bodies of origin in the pars compacta of the substantia nigra, but also provided information sugg ...197546174
corticothalamic neurons and thalamocortical terminal fields: an investigation in rat using horseradish peroxidase and autoradiography.subsequent to thalamic injections in rats of horseradish peroxidase (hrp) alone or hrp and [3h]leucine in combination, the cells of origin of the corticothalamic projections and the terminal fields of the thalamocortical projections were identified. hrp-labeled corticothalamic neurons were uniformly found in layers v and vi. they were medium to small in size and always pyramidal in shape with the larger neurons being found in layer v. on the other hand, 3 different patterns for the distribution ...197546175
use of peroxidatic-enzyme staining to enhance resolution of cultured mammalian cells under phase microscopy.staining of glutaraldehyde-fixed mammalian cells with peroxidatic enzymes (horseradish peroxidase or horse heart cytochrome c) greatly enhances resolution of their structure under phase microscopy. the topography of cell processes and regions of intercellular contact and overlapping is resolved precisely, even in dense cultures mounted in media which ordinarily do not permit clear demonstration of these areas. the technique is therefore a useful aid to the study of cultured cells with phase opti ...197546631
enzymatic activation and trapping of luminol-substituted peptides and proteins. a possible means of amplifying the cytotoxicity of anti-tumor antibodies.glutathione and glucose oxidase (ec conjugates containing covalently bound luminol were prepared as prototypes for peptides and proteins with latent, enzyme-activatable chemical reactivity. in the presence of small quantities of activated horseradish peroxidase, conjugated luminol molecules were oxidized to unstable free radicals which reacted rapidly with soluble proteins and cells. these observations are of interest in regard to possible sequential localization reactions in which a fe ...197547175
histological evidence for direct connections between the optic lobes of the cockroach leucophaea maderae.heretofore, descriptions of direct interconnections between insect optic lobes have been based on histological examinations of normal brains or on inference from electrophysiological or behavioral data. we present here what we believe to be the first demonstration of such monosynaptic connections by techniques of experimental neuroanatomy. twenty-four to 39 h after extirpation of the left optic lobe, degenerating axons and axon terminals, as silvered by a modified nauta technique, were abundant ...197547256
genetic control of sensitization to structurally unrelated antigens and its relationship to histocompatibility antigens in guinea-pigs.five strains of guinea-pigs homozygous for gpl-a and 2/13 histocompatibility antigens were sequentially immunized with seven structurally unrelated antigens (tgal, bpo-bgg, asan, bpo-pll, phenetidine, horseradish peroxidase and dnp-dodecapeptide). considerable differences in the immune response were observed, as measured by delayed skin reactivity and antigen-induced lymphocyte stimulation in vitro. the data presented show that when the progeny of various back-cross matings are analysed for thei ...197547308
olivocochlear and vestibular efferent neurons of the feline brain stem: their location, morphology and number determined by retrograde axonal transport and acetylcholinesterase histochemistry.anterograde degeneration studies have shown that the cochlear and vestibular receptor organs receive an efferent innervation from neurons in the brain stem. this pathway may provide a mechanism by which the cns could modulate its own afferent input. the neurons which provide this innervation have so far escaped positive identification with methods which depend on retrograde cell changes after axotomy. in the present study, horseradish peroxidase (hrp) was injected into the labryinths of kittens ...197547866
a comparative study of horseradish peroxidase conjugates prepared with a one-step and a two-step this study we compared horseradish peroxidase (hrp)-labeled rabbit antihuman immunoglobulin g (igg) conjugates, prepared by a one-step and a two-step method. glutaraldehyde was used as a cross-linking agent. two methods were used for removing unconjugated hrp: sephadex g-200 gel chromatography and ammonium sulfate precipitation. the conjugates were characterized immunologically, immunochemically and enzymatically. the immunohistoenzymic properties of the conjugates were tested on unfixed cryo ...197547869
the retrograde transport method.after an injection of horseradish peroxidase into the brain, the enzyme product can later be found in cell bodies of neurons which project axons to the injection site. the use of the tracer has now been adapted as a means of identifying neurons on the basis of their efferent fiber projections. in this review particular attention is paid to characteristics of the phenomenon of retrograde transport, such as diffusion of the marker from the injection site and the region of effective uptake, uptake ...197548482
retrograde axonal transport of horseradish peroxidase in peripheral autonomic exogeneous marker protein, horseradish peroxidase (hrp) was used to race peripheral autonomic pathways in adult guinea pigs and cats. small doses of hrp were injected into various organs and after a brief survival period, hrp activity appeared in the perikarya of autonomic neurons that supplied each injection site. after injection of hrp into the anterior chamber of the eye, reaction product was detected in the postganglionic sympathetic neurons of the superior cervical sympathetic ganglion. ...197548519
retrograde transport of horseradish peroxidase in the magnocellular neurosecretory system of the rat.horseradish peroxidase (hrp) was injected into the pituitary in adult rats. after 2-3 days, the neurones of the supraoptic nuclei, the magnocellular parts of the paraventricular nuclei, and the various accessory neurosecretory hypothalamic nuclei showed accumulation of hrp. the hrp reaction product consisted of fine, discrete cytoplasmic granules, and in electron micrographys it was seen to be located in the lysosome-like dense bodies of 0.4-0.6 mum diameter which are normally present in the cyt ...197549208
the origin of fornix fibers which project to the mammillary bodies in the rat: a horseradish peroxidase study. 197549209
demonstration of nigrothalamic connections in the cat by retrograde axonal transport of horseradish peroxidase. 197549210
purification of mouse alpha1-fetoprotein and preparation of specific peroxidase conjugates for its cellular localization.mouse alpha1-fetoprotein (afp) was isolated from amniotic fluid by immunoadsorbent columns and preparative electrophoresis. specific antibodies were isolated from monospecific hyperimmunsera by use of immunoadsorbents, and subsequently coupled with horseradish peroxidase. at the light microscopical level, purified antibody-peroxidase conjugates were used for the cellular localization of afp in fetal liver by direct and indirect staining methods. fixatives containing ethanol or aldehydes were tri ...197549343
caveola--vesicle complexes in the plasmalemma of erythrocytes infected by plasmodium vivax and p cynomolgi. unique structures related to schüffner's dots.erythrocytes infected with plasmodium vivax and p cynomolgi, characterized by schüffner's dots on giemsa-stained thin films, were studied by electron microscopy and immunocytochemistry. a caveola-vesicle complex, which consisted of a caveola surrounded by vesicles, in an alveolar fashion, formed along the erythrocyte plasmalemma. horseradish-peroxidase-labeled immunoglobulin from a monkey infected with p vivax bound to the vesicle membrane. cationized ferritin appeared within the vesicles after ...197550017
the horseradish peroxidase technique applied to the teleostean nervous system. 197550115
projections to the gyrus proreus from the brain stem tegmentum (locus coeruleus, raphe nuclei) in the cat, demonstrated by retrograde transport of horseradish peroxidase. 197550117
[uptake and transport of exogenous peroxidase in the masticatory muscles of cats. localization of ganglionic neurons].retrograde axonal transport of horseradish peroxydase (hrp) has been used to trace the cells of origin of proprioceptive fibers in jaw-closing and jaw-opening muscles. after injection of hrp in young cats' masticatory muscles (masseteric, temporal, pterygoid, mylohyoid and digastric) labelled neurons were found in the ipsilateral semi-lunar ganglion and trigeminal mesencephalic nucleus. it is concluded that sensory endings are present in jaw-opening as in jaw-closing muscles; possibly the affere ...197550149
[uptake and transport of exogenous peroxidase in the masticatory muscles of the cat. localization of motor neurons].in the present work, a topographical localization of masticatory muscle motoneurons was undertaken. horseradish peroxydase injected in each muscle can be transported in the retrograde direction to the corresponding motoneurons cell bodies. jaw-closing muscle motoneurons were identified in the dorsal part of the motor trigeminal nucleus whereas jaw-opening muscle motoneurons were observed in the ventro-medial region.197550152
ultrastructural localization of in vivo-bound complement in bullous pemphigoid.antihuman complement component c3 labeled with horseradish peroxidase was used to reveal the ultrastructural localization of complement in two cases of bullous pemphigoid. the complement deposits were shown to be exclusively located in the space between the plasma membrane of the basal cells and the basal lamina. this corresponds exactly to the ultrastructural localization of immunoglobulins in bullous pemphigoid.197550388
studies on the cerebellar projections from the main and external cuneate nuclei in the cat by means of retrograde axonal transport of horseradish peroxidase.the cerebellar projections from the main and external cuneate nuclei in the cat have been studied by means of retrograde axonal transport of horseradish peroxidase. the main projection from the external cuneate nucleus (ecn) is to the intermediate and, possibly, the small lateral part of lobule v and to the paramedian lobule on the ipsilateral side. the projection from the ecn to the cerebellar regions mentioned is topographically organized. cells in the caudal part of the ecn send their axons t ...197550867
ultrastructural localization of gamma-chain and immunoglobulin g in human lymphocytes using enzyme-labeled fab the use of rabbit antibodies against the heavy chain of human immunoglobulin g (igg), the gamma-chain and igg molecules were successfully localized at the ultrastructural level in human peripheral lymphocytes. the rabbit fab fragment was coupled to horseradish peroxidase by means of glutaraldehyde and the resulting conjugate could penetrate the intact plasma membrane. discernible reaction product was observed in cisternae of the nuclear envelope, rough endoplasmic reticulum and golgi apparatu ...197551039
the identification of striatal and pallidal neurons projecting to substantia nigra. an experimental study by means of retrograde axonal transport of horseradish peroxidase. 197551667
a dual marking technique for microelectrode tracks and localization recording sites.this paper describes techniques for marking both microelectrode tracks and exact recording loci using a combination of fast green dye and horseradish peroxidase (hrp). the procedure involves coating the exterior of hrp filled microelectrodes with fast green dye in order to identify electrode tracks, and ejecting hrp from the electrode to mark recording loci. rapid, multiple marks can be made with this technique without harming the recording capabilities of the micropipette.197551724
localization of alpha-d-glucosyl and alpha-d-mannosyl groups of mucosubstances with concanavalin a and horseradish peroxidase.concanavalin a is a lectin which is known to bind specifically to alpha-d-glucosyl and alpha-d-mannosyl groups in the mucosubstances of mammalian tissues. the lectin molecule is bivalent; after its attachment to mucosubstances present in a histological specimen it can also bind horseradish peroxidase, a mannose-containing glycoprotein. the attached peroxidase may then be visualized by virtue of its histochemically demonstrable enzymatic activity. other investigators have utilized this principle ...197552638
a study of the dynamics of retrograde transport and accumulation of horseradish peroxidase in injured neurons.the phenomenon of retrograde intraaxonal transport of extracellular markers introduced at the level of the axon terminal has been suggested as a possible mechanism of communication between the axon terminal and the neuron cell body. we tested the hypothesis that communication after axotomy might consist of a change in the rate of uptake or of transport of material by injured neurons. small lesions were made with a needle in one retinal quadrant of chicks and immediately afterwards horseradish pe ...197553088
preganglionic innervation of the adrenal gland of the rat: a study using horseradish peroxidase. 197553160
the pinocytic rate of activated macrophages.peritoneal macrophages from mice injected 4 days previously with brewer's thioglycollate medium have a pinocytic rate, in culture, of 190 ng horseradish peroxidase (hrp)/100 mug cell protein/h, compared to the rate of resident peritoneal cells of 53 ng hrp/100 mug cell protein/h. mice injected with endotoxin or with only certain of the components of the brewer's medium show an intermediate level of stimulation. the rate of unstimulated, endotoxin-stimulated, or thioglycollate-stimulated cells sh ...197553258
retrograde transport of horseradish peroxidase in transected axons. ii. relations between rate of transfer from the site of injury to the perikaryon and onset of chromatolysis.the sciatic nerves of 2--3 month-old mice, rats and rabbits were crushed and at the same time horseradish peroxidase (hrp) was applied around the crushed region at mid-thigh level. at varying time intervals thereafter, hrp was seen in neurons of the corresponding spinal ganglia and levels of the spinal cord. the rate of ascent of hrp appeared to be similar in the different animals and to be independent of the length of the nerve. the accumulation of hrp was more conspicuous in small than large n ...197553277
localization of laryngeal motor neurons in the a series of 12 newborn kittens, horseradish peroxidase (hrp) was used to trace retrograde axoplasmic flow in the motor neurons to laryngeal muscles. the animals were sacrificed 24 hours after injection of hrp into a specific laryngeal muscle, and the brain stems were stained for peroxidase. this clear-cut colorimetric method permitted the localization of the motor neurons in two nuclei of the ipsilateral brain stem. these are the nucleus ambiguus and the retrofacial nucleus. the primary sourc ...197553770
electron microscopic demonstration of immunoglobulin deposition in rheumatoid cartilage.horseradish peroxidase (hrpo) conjugated with goat antihuman igg, goat antihuman igm, and aggregated human igg has been used as a enzymatic marker to stain igg, igm, and rheumatoid factor in rheumatoid cartilage. when hrpo-anti igg and hrpo-anti igm were used, immunoglobulin deposits were not observed in nonrheumatoid cartilage. however 7 of 8 rheumatoid cartilage specimens stained with hrpo-anti igg showed electron-dense deposits. three rheumatoid specimens stained with hrpo-anti igm showed sim ...197554168
rôle of axonal transport in maintaining central synaptic connections.synaptic boutons on the somata of rat hypoglossal neurones have been stained with zinc iodide-osmium, and counted using light microscopy. two weeks after silastic cuffs containing colchicine or vinblastine were applied to the hypoglossal nerve, the number of boutons on parent nerve cell bodies was significantly lower than controls. these drugs inhibited retrograde axonal transport of horseradish peroxidase, but did not affect neuromuscular conduction or the number of axons in the nerve trunk. cu ...197554262
in vitro formation of gap junction vesicles.a method is described that uses trypsin digestion combined with collagenase-hyaluronidase which produces a population of gap junction vesicles. the hexagonal lattice of subunits ("connexons") comprising the gapjunctions appears unaltered by various structural criteria and by buoyant density measurements. the gap junction vesciles are closed by either a single or a double profile of nonjunctional "membrane," which presents a smooth, particle-free fracture face. horseradish peroxidase and cytochro ...197654358
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