Superoxide dismutase application

Noor R, Mittal S, Iqbal J (2002) Superoxide dismutase - applications and relevance to human diseases. Med Sci Monit 8(9) 210-215... 

C. Beauchamp and I. Fridovich, Superoxide dismutase. Improved assays and an assay applicable to acrylamide gels. Anal. Biochem. 44, 276-287 (1971). 

Several enzymes have been immobilized in sol-gel matrices effectively and employed in diverse applications. Urease, catalase, and adenylic acid deaminase were first encapsulated in sol-gel matrices [72], The encapsulated urease and catalase retained partial activity but adenylic acid deaminase completely lost its activity. After three decades considerable attention has been paid again towards the bioencapsulation using sol-gel glasses. Braun et al. [73] successfully encapsulated alkaline phosphatase in silica gel, which retained its activity up to 2 months (30% of initial) with improved thermal stability. Further Shtelzer et al. [58] sequestered trypsin within a binary sol-gel-derived composite using TEOS and PEG. Ellerby et al. [74] entrapped other proteins such as cytochrome c and Mb in TEOS sol-gel. Later several proteins such as Mb [8], hemoglobin (Hb) [56], cyt c [55, 75], bacteriorhodopsin (bR) [76], lactate oxidase [77], alkaline phosphatase (AP) [78], GOD [51], HRP [79], urease [80], superoxide dismutase [8], tyrosinase [81], acetylcholinesterase [82], etc. have been immobilized into different sol-gel matrices. Hitherto some reports have described the various aspects of sol-gel entrapped biomolecules such as conformation [50, 60], dynamics [12, 83], accessibility [46], reaction kinetics [50, 54], activity [7, 84], and stability [1, 80],... 

The applicability of CE-ICP-MS for fast screening of weak metal interactions of Cd2+ with several test proteins (such as carbonic anhydrase from bovine erythrocytes, bovine serum albumin, human holotransferrin, ceruloplasmin and superoxide dismutase) has been studied by Cahmoun and Hagege.74 The sensitivity of element species and their detection limits in CE-ICP-MS have been improved by introducing a preconcentration step involving large volume stacking with polarity... 

Since the principal constituents of milk are proteins, lipids and lactose, proteinases, lipases and / -galactosidase (lactase) are the principal exogenous enzymes used in dairy technology. Apart from these, there are, at present, only minor applications for glucose oxidase, catalase, superoxide dismutase and lysozyme. Lactoperoxidase, xanthine oxidase and sulphydryl oxidase might also be included, although at present the indigenous form of these enzymes is exploited. 

The biological role and the clinical applications of superoxide dismutases are covered by the second volume of the Symposium in Malta... 

Inhibition by superoxide dismutase (SOD) Simple, highly specific Only applicable to superoxide... 

As would be expected, several additional applications of cryoprobe technology in the area of biomacromolecular NMR were also published. Goger et al,253 described the reduction in time required for the acquisition of triple resonance NMR experiments performed on proteins. Later in the year, Craik et al.254 reported a study of the 21 amino acid bacterial peptide microcin J25 that relied on cryoprobe technology. In late 2003, Bertini and co-workers255 reported the application of cryoprobe-based 13C direct-detection NMR experiments on a paramagnetic oxidized superoxide dismutase. 

The first application on a biological system was performed in the mid-90 s on a gas phase cluster model of the active site of superoxide dismutase [11]. Since then a rapidly increasing number of applications to biological systems have been reported. In this article, we are trying to give an overview of the current status by giving a short outline of the studies that appeared so far in the literature and by presenting selected examples from our own work on enzymatic systems. 

Another possibility for therapeutic application of polymer vesicles has been presented recently [242], Superoxide dismutase, an antioxidant enzyme, was encapsulated in the vesicular cavity and shown to remain functional in neutralizing superoxide radicals in situ. The polymer membranes were proven permeable to superoxide radicals by pulse radiolysis, and the encapsulation of the enzyme prolongs its lifetime (which is only minutes in the bloodstream, when non-shielded). 

Al. Adachi, T., Usami, Y., Kishi, T., Hirano, K., and Hayashi, K., An enzyme immunoassay for cuprozinc superoxide dismutase using monoclonal antibodies Application for pharmacokinetic study. J. Immunol. Methods 109, 93-101 (1988). 

If low-valent M" + compounds are used, peroxides form instead (see below). Most transition metal ions catalyze, to some degree, catalytic decomposition of superoxides (display superoxide dismutase activity), thus limiting applicability of reaction (4.32) for the synthesis or in situ generation of metal superoxo complexes. 

The mechanisms by which manganese complexes and manganese superoxide dismutase react with superoxide radicals are of interest as knowledge of the kinetic parameters and the reaction pathways may allow the synthesis of model compounds with specific chemical features. These compounds may then have clinical application or may allow the control of specific redox chemistry in catalytic processes. 

This mechanism may not, however, be applicable to all the iron superoxide dismutases. This is because the iron enzyme from E. coli was found to exhibit saturation kinetics (Fee et al., 1981). 

In contrast the manganese superoxide dismutase appears to exhibit complex kinetics. The simple scheme of one electron reduction and oxidation of the metal appears not to be applicable. Pick et al. (1974) investigating the manganese superoxide dismutase from . coli suggested that not two but four oxidation-reduction reactions are involved and that each reaction is characterized by a different second-rate constant ... 

Superoxide dismutase will scavenge the Of formed and will therefore inhibit the reduction of the dianisidine radical by Of. Consequently the dianisidine radical will dismute to yield the divalently oxidized dianisidine. In the presence of superoxide dismutase this reaction is augmented (Fig. 6). The possibility that Of could reduce the final product of dianisidine oxidation and reverse the change in absorbance at 460 nm was tested and was excluded. The assay has been used to determine the rate constant for purified swordfish liver copper/zinc superoxide dismutase (Bannister et al., 1979) and could be applied to crude extracts. The assay was also found applicable to polyacryalmide gels (Misra and Fridovich, 1977c). Gels soaked in riboflavin plus dianisidine, and subsequently illuminated, developed stable brown bands. Peroxidases are also stained by this procedure due to the photochemical production of hydrogen peroxide. However, the development of bands due to peroxidase activity is much slower than the development of bands due to dismutase activity. 

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