Nitration protein

Proteins, Nitrated. Proteinaceous or albuminoid materials (glue, bones, hides, leather, hair, feathers, etc) can be nitrated in a two-stage process to yield expl yel oils. Thus, glue is treated first with 3.6 pts by wt of 66°Be sulfuric acid and 2.7 pts of 36°Be nitric acid. The resultant oil is sepd from the heavier spent acid and nitrated further with 3 pts of oleum and 2.6 pts of 36°BS nitric acid. Both nitrations are conducted at 15—20°, and never above 40°. The resulting oily expl can be used alone or mixed with other materials... 

Similar to peroxynitrite, ONOOCOO- reacts with many biomolecules such as uric acid [110], oxyhemoglobin [133], melatonin [135], NADH, ubiquinol Q0, and glutathione [141], Reactions of ONOOCOO with substrates in mitochondrial matrix is accompanied by protein nitration [141]. The reaction of ONOOCOO- with GSH was so rapid that glutathione inhibited tyrosine nitration by peroxynitrite in the presence of C02 [142], The formation of ONOOCOO- increased the formation of 3-nitrotyrosine and decreased the formation of 3-hydroxytyrosine probably due to the enhanced selectivity of C03 - compared to hydroxyl radicals [143],... 

It follows from the above that MPO may catalyze the formation of chlorinated products in media containing chloride ions. Recently, Hazen et al. [172] have shown that the same enzyme catalyzes lipid peroxidation and protein nitration in media containing physiologically relevant levels of nitrite ions. It was found that the interaction of activated monocytes with LDL in the presence of nitrite ions resulted in the nitration of apolipoprotein B-100 tyrosine residues and the generation of lipid peroxidation products 9-hydroxy-10,12-octadecadienoate and 9-hydroxy-10,12-octadecadienoic acid. In this case there might be two mechanisms of MPO catalytic activity. At low rates of nitric oxide flux, the process was inhibited by catalase and MPO inhibitors but not SOD, suggesting the MPO initiation. 

Albumin and Protein, Nitrated. See Protein and Albumin Nitrated Alcohol (Span). Alcohol Alcohol An organic alkyl compd contg a hydroxyl group. It is also the common name for ethyl alcohol or ethanol. This and other alcohols, as well as their nitrated derivs, are described under individual names, such as allyl-, amyl, butyl-, ethyl-, methyl-, propyl-, etc... 

It has been suggested that protein nitration, particularily tyrosine residues, is a specific footprint of peroxynitrite presence in biological systems (12). However, this concept cannot be held in the light of recent data. The gas phase of cigarette... 

Protein Functions Carbonylated Proteins Nitrated Proteins References... 

NO reacts with superoxide, a toxic anion produced in the cells, to formper-oxynitrite (a potent protein nitrating agent) especially after reacting with carbon dioxide (Radi et al 1999) (Fig. 3). The level of superoxide is kept low in the cell by superoxide dismutase, an antioxidant enzyme. Increased levels of superoxide may be caused either by the overproduction of NAD(P)H oxidases and NOSs or by processes that produce ROSs, such as the electron transport chain (ETC) in mitochondria or by xanthine oxidase (Beckman, 1996 Xia et al., 1996 Ischiropoulos, 1998). 

Recently, several studies suggested that protein nitration could be a cellular signaling mechanism and is often a reversible and selective process, similar to protein phosphorylation (Aulak et al., 2004 Koeck et al., 2004). In addition, modified proteins are believed to be either degraded or subject to processes that could lead to enzymatic denitration (Gow et al., 1996 Kamisaki et al., 1998 Me et al., 2003). The latter possibility is intriguing because this would allow the process of tyrosine nitration to be reversible and thus enable a more dynamic physiological role. Protein nitration is observed under normal conditions in all tissues. In AD brain levels of nitrated proteins were found to be increased compared to that of control (Smith et al.. 

Aulak KS, Koeck T, Crabb JW, Stuehr DJ (2004) Dynamics of protein nitration in cells and mitochondria. Am J Physiol Heart Circ Physiol 286 H30-H38... 

Schopfer FJ, Baker PR, Freeman BA (2003) NO-dependent protein nitration a cell signaling event or an oxidative inflammatory response Trends Biochem Sci 28 646-654... 

Prolonged elevation of intraeellular Ca " " levels also interrupts the electron transport chain, leading to accumulation of hydrogen peroxide and superoxide, which further react to form hydroxyl radicals. Superoxide also reacts with nitric oxide to form peroxynitrite, contributing to excito-toxicity associated with isehemia (Dawson and Dawson, 1998) and leading to lipid peroxidation and protein nitration. 

S. L. Hazen, R. Zhang, Z. Shen, W. Wu, E. A. Podrez, J. C. MacPherson, et al.. Formation of Nitric Oxide-Derived Oxidants by Myeloperoxidase in Monocytes Pathways for Monocyte-.Mediated Protein Nitration and Lipid Peroxidation in Vivo, Circ Res 85 (1999) 950-8. 

J. A. Sloane, W. Hollander, M. B. Moss, D. L. Rosene, C. R. Abraham, Increased Microglial Activation and Protein Nitration in White Matter of the Aging Monkey, Neurobiol Aging 20 (1999) 395-405. 

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