Horse-radish

This enzyme Is widely distributed, more particularly in plants. Three important sources of the enzyme are horse-radish, turnips and milk. Peroxidase is capable of activating both hydrogen peroxide and a suitable substrate so that the latter is oxidised, although hydrogen peroxide alone may be incapable of affecting this change. It sometimes happens that hydrogen pcr-... 

Horse radish peroxidase, H2O2 or Laccase, pH 4, 2% DMSO or DMF. Cleavage occurs by the formation of a phenyldiimide, which decomposes to the acid, nitrogen, and benzene. The laccase method is compatible with the readily oxidized tryptophan and methionine because it does not use peroxide. ... 

Sulfur compounds first detected in plants hy N. Deyeux (root.s of the dock, horse-radish, and cochlearia). 

Fig. 6.2.3 Luminescence spectra of pholasin in the presence of horse radish peroxidase (solid line from Henry et al, 1973 with permission from Elsevier), and in the presence of FeSC>4 in 10 mM phosphate buffer, pH 7.0, containing 0.1 M NaCl (dashed line Shimomura, 1980, unpublished).

Peroxidase activity has long been associated with extracts of plant tissue and the crystalline enzyme from horse radish root has been studied in extenso, particularly in regard to its mechanism of action (11). Plants also contain ferredoxin and various specialized cytochromes, both of which substances play an essential role in photosynthesis (95, 96). Agavain, a crystalline proteolytic enzyme from the leaves of Agave,... 

Seed coating with extracts of mustard (Sinapis alba) and horse radish (.Amoracia lapathifolia) was shown to have high efficacy against T. caries spores but not Fusarium spp. (SpieB and Dutschke, 1991). 

D-tubocurarine from Chondrodendron tomentosum Ruiz et Pav. and Rauvolfia serpentina Benth. et Kurz and horse radish peroxidase 3 mg/ml, which prevent the peroxide formation, block the fruit formation as a whole, while yohimbine and gaillardine inhibit the seed formation. Neostigmine stimulates the fruit and seed yield, although its precursor physostigmine has no significant effect (Roshchina and Melnikova, 1998). 

In the reaction of luminol, hydrogen peroxide, and horse radish peroxidase 122> the chemiluminescence intensity is proportional to the square of luminol radical concentration. The lifetime of these luminol radicals was found by ESR techniques to be about 10 sec. Titration studies revealed that luminol acts as two-electron donor during the reduction of a hydrogen peroxide-horseradish peroxidase complex. The enzyme is not involved in the reaction step leading directly to light emission. This step is formulated as... 

It has been suggested that N02 might be formed by the oxidation of nitrite by numerous biological oxidants. Thus, Shibata et al. [90] reported that horse radish peroxidase (HRP) + hydrogen peroxide oxidized nitrite by the following mechanism ... 

Colorless gas with a "very offensive" odor that resembles decayed horse radish detectable at 0.3 ppm. However, can cause olfactory fatigue and sense of smell is not reliable. This material is hazardous through inhalation and produces local skin/eye impacts. It is highly flammable. 

Fig. 6.2 Tyramide signal amplification. T is the labeled tyramine and HRP, horse radish peroxidase. The Label can be a lluorochrome or biotin. The lluorochrome can be visualized directly in a fluorescence microscope. Biotin can be visualized via labeled streptavidin...

Hermann (2000) described a rapid automated method involving generation of a known amount of free radicals and the detection of the excess by photochemiluminescence. Test kits are available for determination of total water-soluble antioxidants, fat-soluble antioxidants and ascorbic acid. A luminometric method was developed for the determination of antioxidative activity and was subsequently applied to anthocyanin and betalaine colour concentrates (Kuchta et al., 1999). The method involved quantification of the interruption in luminescence from the hydrogen peroxide-horse radish peroxidase-luminol system in the presence of antioxidants. 

Neeser and Schweizer introduced 4 M CF3CO2H for 1 h at 121° for hydrolysis of glycoproteins. Both neutral and amino sugars were considered. They compared this method to hydrolysis with 0.6 M hydrochloric acid for 4 h at 100° and 3 M hydrochloric acid for 0.75 h at 125°. Hydrolysis of fetal-calf-serum fetuin, bovine submaxillary mucin, and horse-radish peroxidase showed hydrolysis with CF3CO2H to be superior. 

Bos, E., van der Doelan, A., van Rooy, N., and Schuurs, A. (1981) 3,3, 5,5 -tetra-methylbenzidine as an Ames test negative chromogen for horse-radish peroxidase in enzyme-immunoassay. J. Immunoassay 2, 187-204. 

Horse radish peroxidase on the other hand, is a hemoprotein which is inhibited by alkylation of the porphyrin ring 48 by a -propionic acid radical resulting from the ring cleavage of the cyclopropanone hydrate 21, providing the car-boxylate 49,Eq. (17). 

SPRi interactions Between 3-D NPH-SA or 2-D SA and Biotinytated Horse Radish Peroxidase (b-HRP)... 

Fig. 5. The effect of SA/polymer or SA concentrations in feed to the amount of reacted biotinylated Horse Radish...

Horse radish Armoracia rusticana roots AOT/C7-C15 n-alcohols Extraction and purification [49]... 

Cardoso et al. [115] have shown that AOT concentration is related to percolation. The percolation phenomenon was followed by a steep increase in the micellar conductivity [115]. Huang and Lee [49] observed a drastic reduction in the recovery (around 40%) of the horse radish peroxidase when AOT concentration was at 5 mmol 1 and further increase in AOT concentration to 10 mmol 1- produced no recovery at all. 

Horse radish peroxidase (HRP) from Armoracia rusticana roots... 

Both RID and ELISA were used as the control tests for detection of the specific anti-viral Ab. Anti-bovine Ab labeled with the horse radish peroxidase ( Sigma , USA) was used in the ELISA assays. IDEX system (USA) served as the control. 

The enzymes commonly used as labels in ELISA and other immunochemical reactions include horse radish peroxidase (HRP) and alkaline phosphatase (AP). The enzyme can be covalently coupled to the antibody using glutaraldehyde conjugation to reactive amino groups on the enzyme (lysines) in a phosphate buffered aqueous solution at neutral pH, as shown in Fig. 19 (103). Alternatively, carbohydrates present in the immunoglobulin structure can be cleaved by periodate treatment (see Fig. 20) and bound to free amino groups on the enzyme through a Schiff base reaction (103). 

The oxidation of DOPA and adrenaline to dopachrome and adrenochrome, respectively, by a horse radish peroxidase-H202 system has been reported by Herzmann.29,30 The oxidation process was activated by trace quantities of caffeic acid, its esters, and related compounds.30 Ascorbic acid inhibited the oxidation of adrenaline by this enzyme in the initial stages of the reaction, but later had a stimulatory effect.30... 

If we consider the fate of substrate AH2 during the action of a peroxidase, we see that donation of an electron to compound I to convert it into II (Fig. 16-14, step c) will generate a free radical AH as well as a proton. The radical may then donate a second electron to II to form the free enzyme. Alternatively, a second molecule of AH2 may react (Fig. 16-14, step c) to form a second radical AH. The two AH radicals may then disproportionate to form A and AH2 or they may leave the enzyme and react with other molecules in their environment. Compound II of horse radish peroxidase is able to exchange the oxygen atom of its Fe(IV)=0 center with water rapidly at pH 7, presumably by donation of a proton from the nearby histidine side chain (corresponding to His 52 of Fig. 16-13).227/230a/b This histidine presumably also functions in proton transfer during reactions with substrates (see Fig. 16-11B).224... 

The elution pattern in IEC results from the charge distribution on the folded chain. Therefore, IEC was used for indication, whether the native structure of the protein had been affected by previous RPC or not. Ribonuclease was found to retain its native structure, whereas bovine serum albumin, horse radish peroxidase, and ovalbumin were much altered through RPC on a C 18 column with a gradient water/ (ethanol-butanol 80 20) containing 0.012 M HC1 in both eluent components 59>. 

Fig. 18. Dynamics of oxidative decomposition of 3-indolylacetic acid (I) and its silatranemethyl ester (2) by horse-radish crystalline peroxidase...

The sections are incubated for 1 hr with the primary monoclonal antibody, mouse antihuman mast cell tryptase antibody (DAKO), diluted 1 200 with 1% BSA/PBS. They are washed for 10 min in PBS using magnetic stirring, incubated with biotinylated antimouse antibody for 15 min, and washed in PBS. This is followed by adding avidin-biotin-horse-radish peroxidase for 15 min. A Vector DAB Substrate kit is applied to develop the reaction product by using nickel-DAB (5 min developing time) according to the manufacturer s instructions. This step yields a black reaction product at sites of mast cell tryptase. 

Most electrochemical immunosensors use antibodies or antigens labelled with an enzyme that generates an electroactive product which can be detected at the electrochemical transducer surface. The combination of high enzyme activity and selectivity with the sensitive methods of electrochemical detection provides a basis for the development of immunosensors. Horse radish peroxidase (HRP) and alkaline phosphatase (AP) are popular enzyme labels and can be used with a variety of substrates. 

Torriero et al. [30] managed to estimate the concentration of lactate in untreated milk without the use of a microdialysis unit. Samples were fed into a reactor consisting of a rotating disc bearing lactate oxidase which by its motion ensured adequate mass transport of hydrogen peroxide to an enzyme electrode. The electrode consisted of horse-radish peroxidase immobilised over osmium on the surface of a glassy carbon electrode. Such an electrode can be poised at 0.0 Y so avoiding electrochemical... 

Steuhl, P., and J.W. Rohen. 1983. Absorption of horse-radish peroxidase by the conjunctival epithelium of monkeys and rabbits. Graefes Arch Clin Exp Ophthalmol 220 13. 

Wilson, M. B. and Nakane, P. P. (1978) Recent developments in the periodate method of conjugating horse radish peroxidase (HRPO) to antibodies, in Immunofluorescence and Related Staining Techniques (Knapp, W., Holubar, K., and Wick, G., eds.), Elsevier/North Holland Biomedical, Amsterdam, pp. 215-224. 

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