Peroxidase active materials

Detecting the presence of small, even invisible, amounts of blood is routine. Physical characteristics of dried stains give minimal information, however, as dried blood can take on many hues. Many of the chemical tests for the presence of blood rely on the catalytic peroxidase activity of heme (56,57). Minute quantities of blood catalyze oxidation reactions between colorless materials, eg, phenolphthalein, luco malachite green, luminol, etc, to colored or luminescent ones. The oxidant is typically hydrogen peroxide or sodium perborate (see Automated instrumentation,hematology). 

Neuroanatomists have taken advantage of the phenomenon of fast retrograde transport to locate remote nerve cell bodies in the CNS of an experimental animal that are connected to an identified axonal fiber tract whose origin is uncertain. The tracer material [purified horseradish peroxidase (HRP) enzyme] is injected in the region of the axon terminals, where it is taken up by endocytosis and then is carried by retrograde axonal transport over a period of several hours to days back to the nerve cell body. The animal is sacrificed, and the enzyme tracer is localized by staining thin sections of the brain for peroxidase activity. 

Effects of Allelochemicals on Algal Peroxidase (POD) Activity Materials required... 

Other investigators [16] have observed a decrease in horse-radish peroxidase activity in the presence of natural humic acids. However, their experiments were conducted at up to 1600 mg/L of humic acid. A recent review [17] of water treatment for organic carbon removal included raw water TOC values in the range of 1—16 m L. The TOC value can be used as a rough estimate of humic substances as 90% of natural TOC is usually humic material [15 ]. Therefore, the experiments conducted here are for relatively low humic concentrations (2 m L). However, no effects was observed on 2-CP even though the TOC was at a concentration of up to 200 greater than the 2-CP. The humics did not appear to inhibit or compete for the peroxidase. 

To study the possibility for peroxidase activity of catalase initiated by the process of its immobilization on carbon materials is he goal of the present work. The peroxidase fimction of catalase in solutions was well studied on the oxidation of ethyl alcohol, phenol [16,17] and aromatic amines [18]. However, there is no data about peroxidase activity of catalase in immobilized state. Such data is greatly needed because catalase monomers are stable in acid solutions in which the use of peroxidase is impossible due to its deactivation. 

Elder, T., and D. C. Young. 1999. Molecular orbital calculations on the interactions of veratryl alcohol with the lignin peroxidase active site. In Lignin Properties and Materials. W. Glasser, R. Northey and T. Schultz, Eds. American Chemical Society. Washington, DC. 

Catalytic activities of biocomposite materials derived from a-ZrP are collected in Table 9 these are comparable to the corresponding activities of the native proteins in aqueous solutions. In some cases they are enhanced for example, the peroxidase activity of bound Mb is greater when 4-methoxy phenol, and other para-substituted phenols were used as substrates (256). This is one of the rare examples where the bound protein had a higher activity. The catalytic data provided later clearly establish the versatility of a-ZrP in providing a benign medium for the incorporation of delicate proteins/enzymes for biocatalytic applications. 

Advantages. The gasometric catalase assay methods can be used for any kind of biological material a purification of the enzyme is not required. The assay is independent of small amounts of peroxidase activity. It is fairly simple to perform, it is rapid, and it can be adapted to a continuous recording of the reaction. 

Recently, some papers have started to highlight the performance of PSf-(bio) composites-CNT as electrode material for electrochemical immunosensing [112]. The authors have highlighted the attractive combination of PSf/CNTplus disposable screen-printed electrodes for monitoring the errzymatic activity of horseradish peroxidase and the RIgG inmunosensor response. In both cases an enhanced electroanalytical response was demonstrated in comparison with standard graph-ite/PSf composites. 

The enzyme or the chromogen detection system determines whether any endogenous material must first be destroyed. If a peroxidase marker molecule is to be used, endogenous peroxidase or peroxidase-like activity should be blocked. Because these preparations are more fragile than a fixed embedded sample, endogenous enzyme is inactivated with a weaker blocking solution than would... 

Selenium plays a special role in development and protection of spermatozoa (Chapter 15). Tire selenoprotein phospholipid hydroperoxide glutathione peroxidase (PHGPx Eq. 15-58, Table 15-4) has a high activity in the testis and in spermatids. However, in mature spermatozoa it forms an enzymatically inactive oxidatively crosslinked capsular material around the midpiece of the cell perhaps providing mechanical stability.268 A similar 34-kDa selenoprotein is present in sperm nuclei and may be essential for condensation of DNA.269 Sperm tails contain specialized cytoskele-tal proteins which form "outer dense fibers."270 In contrast to mammalian spermatozoa, nematode sperm move by ameboid motility that depends upon a specialized actin-like molecule.271 Sperm cells are unusually rich in polyamines, most of which are bound to RNA and DNA (Chapter 24). 

Wash, hand-peel, chop and lyophilize each plant tissue material for 3-4 h at 25°C (e.g., soybean (Table 17.1), potato, banana, eggplant, sweet potato and artichoke (Table 17.2). Grind the dry tissue to obtain a fine powder and select the particle size using sieves of lower than 200 pm mesh. Store the dry powder in a desiccator at 25°C and use it as the enzymatic source of PPO or peroxidase in the preparation of biosensor. Determine enzymatic activity and total protein content as described in Procedure 22 (in CD accompanying this book). Prepare the carbon paste electrode with dry tissue as described in the same procedure. 

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