Lactoperoxidase and

Since hemoproteins such as lactoperoxidase and catalase are inhibited more rapidly than the sulfhydryl oxidation occurs, it is unlikely that the rapid activation of guanylate cyclase occurs by sulfhydryl oxidation [132]. Prolonged incubation of the papain or dehydrogenase enzymes with substrate and nitroprusside yielded a turbidity which indicated denaturation of the enzyme to an insoluble form, possibly by the formation of disulfide bridges via the dimerization of thiyl radicals [132]. 

As discussed in the earlier survey (1), a biogenic source of polychlorinated dibenzo-p-dioxins and dibenzofurans is peroxidase-catalyzed transformation of chlorophenols as first reported by Oberg and Rappe (2041-2044). More recent studies confirm these observations (2045-2048). In addition to lactoperoxidase and horseradish peroxidase, human leukocyte myeloperoxidase catalyzes in vitro formation of dioxins and dibenzofurans from chlorophenols (2046, 2047). Formation rates are in the pmol/mol range (Scheme 3.6) demonstrating that a human biosynthesis of dioxins and furans is not only possible but also likely. These observations are reinforced by the reported in vivo (rats) conversion of the pre-dioxin nona-chloro-2-phenoxyphenol to octachlorodibenzo-p-dioxin (OCDD) (2049), and the production of hepta- and octachlorodibenzo-p-dioxin in the feces of cows fed pentachlorophenol-treated wood (Scheme 3.7) (2050, 2051). 

Peroxidases from animal sources which have been studied are thyroid peroxidase, lactoperoxidase, myeloperoxidase and glutathione peroxidase. Lactoperoxidase and... 

Chiu, C.K. and Etzel, M.R. 1997. Fractionation of lactoperoxidase and lactoferrin from bovine whey using a cation exchange membrane. J. Food Sci. 62(5), 996-1000. 

Wong, C.W., Watson, D.L., Regester, G.O., and Smithers, G.W. 1998b. Comparison of immunomodulatory properties of purified lactoferrin, lactoperoxidase and (3-casein in sheep. J. Dairy Res. 65, 697-701. 

Battistuzzi G, Bellei M, Vlasits J et al (2010) Redox thermodynamics of lactoperoxidase and eosinophil peroxidase. Arch Biochem Biophys 494 72-77... 

Two principal methods exist for incorporation of I or I into purified antigens. Both involve oxidizing iodide to active iodine, presumably a cationic form of iodine (f), which then reacts with ionized tyrosine residues of the antigen. The first method (12) employs lactoperoxidase and hydrogen peroxide (Figure 8-34) and the second method (14) uses... 

Fibrogen. Two methods were used to prepare I-labeled fibrinogen. In both methods, unincorporated iodide was removed immediately after the reaction by gel filtration on a G-25 Sephadex column preequilibrated in O.OIM HEPES, 0.147M NaCl, 0.02% azide, pH 7.4. The first method uses catalysis by lactoperoxidase and is based on studies by Marchalonis (23), and the second method uses iodine monochloride (ICI) and is based on work by Helmkamp et al. 24). 

Recently, application of lactoperoxidase-catalyzed iodination has taken precedence over non-enzymatic procedures. The enzyme-catalyzed reaction is reported to occur through the formation of an enzyme-substrate complex between the protein substrate and lacto-peroxidase. No detectable free I2 is formed by lactoperoxidase, and selectivity in attaining iodination of surface tyrosine residues in... 

The interaction between an antimicrobial and a pathogen in the laboratory does not take normal host defense systems into account. Humoral and cell-mediated immune systems play a major role in pathogen eradication their contribution is underestimated in susceptibility reports. Antimicrobial agents act in concert with endogenous microbial inhibitors such as immunoglobulins, T lymphocytes, phagocytes, complement components, lactoferrin, lactoperoxidase and lysozymes. 

Tenovuo J, Makinen K, Sievers G Antibacterial Effect of Lactoperoxidase and Myeloperoxidase Against Bacillus cereus. Antimicrob. Agents Che-mother. 1985 27(1) 96-101. 

Benzyl methylsulfide, thioanisol, and thiobenzamide were oxidized by chloroperoxidase, lactoperoxidase, and horseradish peroxidase to the respective sulfoxides. Whereas lactoperoxidase and horseradish peroxidase had low activities towards benzyl methylsulfide, thiobenzamide was efficiently oxidized by lactoperoxidase. Chloroperoxidase had high activity in halide-independent reactions towards all three substrates1251. This enzyme was also used for the asymmetric sulfoxidation of a series of cyclic sulfides. In all cases the (R)-sulfoxides were obtained. In the case of... 

Novel foods include those providing protein (soy and dairy), and those that are intended to improve cardiovascular health (stanol esters, P-glucan, bioactive peptides, and n-3 fatty acids), bone and joint health (calcium, glucosamine, and chondroitin), eye health (lutein), the immune system (milkmicronutrients, lactoferrin, lactoperoxidase, and colostrum), gut health (probiotics and prebiotics), body fitness (conjugated linoleic acid, amino acids, and glyco-macropeptide), energy level, and for beauty. 

Metal-containing enzymes, e.g. lactoperoxidase and catalase, and cytochromes, can act as pro-oxidants owing to the metals they contain rather than enzymatically the pro-oxidant effect of these enzymes is increased by heating (although there are conflicting reports). Xanthine oxidase, which... 

Recently, it has been shown that iodine, as well as 6-iodolactone, also inhibits the proliferation of mammary breast cancer cells (MCF-7) (Aceves et at, 2005). These cells express sodium iodine symporter (NIS) and lactoperoxidase, and therefore exhibit comparable machinery to metabofize iodine to 6-iodolactones fike thyroid cells. This is a new and exciting field, which might have implications for fmther examination into the role of iodine and 6-iodolactone in the treatment of breast cancer (Arroyo-Helguera et al., 2006). In fact Japanese women, with their high daily iodine intake, have a five-fold lower incidence of breast cancer breast cancer was treated in ancient years with high doses of iodine-containing algae. 

Loeb MR, Smith DH. Lactoperoxidase and lodo-Gen-catalyzed iodination labels inner and outer membrane proteins of Haemophilus influenzae. J Bacteriol 1983 155 443-6. 

Enzymatic oxidizing systems are capable of generating reactive oxygen species as well. The system Myavert C uses a balance of lactoperoxidase and glucose oxidase to yield preservation in cosmetic and toiletry formulations (Guthrie, 1992). For optimum performance a target pH of between 4 and 6 should be considered. 

Hydrolases identified include amylases, lipases, esterases, proteinases and phosphatases. Proteinase inhibitors have also been found. Important oxidoreductases in milk are aldehyde dehydrogenase (xanthine oxidase), lactoperoxidase and catalase. A general idea of the occurrence and localization of enzymes in boving milk is given in Table 10.24... 

In lactoperoxidase and verdoperoxidase the hemes are also attached covalently to the protein. No thioether link is present in lactoperoxidase alkaline hydrolysis and HI release mesoporphyrin 160). 

During the trial, feed samples were taken weekly and analyzed for ehemical-nutritional features. Individual DMI and milk yield were measured daily, and representative milk samples from morning milking were collected every 3-4 d and analyzed for fat, protein, lactose, urea and titratable acidity (FT120, Foss Electric, Denmark) SCC (Fossomatic, Foss Electric) rermeting properties (Formawin, Foss Electric) AR measured either on raw milk either on milk after pasteurization (80 °C x 10 ) (Calamari et al., 2003) some milk enzymes involved in the antimicrobial activity of milk or related to the udder health (GOT, GOT, LDH, lactoperoxidase and xanthine oxidase) (Calamari etal., 2003). Fecal samples were also collected at the end of each period and analyzed for pH and DM. 

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