Protein oxidation peroxidation

Similar to lipids the oxidation of proteins has already been studied for more than 20 years. Before discussing the data on protein oxidation, it should be mentioned that many associated questions were already considered in previous chapters. For example, the oxidation of lipoproteins, which is closely connected with the problems of nonenzymatic lipid peroxidation was discussed in Chapter 25. Many questions on the interaction of superoxide and nitric oxide with enzymes including the inhibition of enzymatic activities of prooxidant and antioxidant enzymes are considered in Chapters 22 and 30. Therefore, the findings reported in those chapters should be taken into account for considering the data presented in this chapter. 

In contrast to numerous literature data, which indicate that protein oxidation, as a rule, precedes lipid peroxidation, Parinandi et al. [66] found that the modification of proteins in rat myocardial membranes exposed to prooxidants (ferrous ion/ascorbate, cupric ion/tert-butyl-hydroperoxide, linoleic acid hydroperoxide, and soybean lipoxygenase) accompanied lipid peroxidation initiated by these prooxidant systems. 

Semen, reactive oxygen species, 612 Sensorial quaUty appreciation, oxidation stabihty, 664 Semm protein oxidative damage, 614 see also Human seram Sesquiterpenes, stractural chemistry, 133-6 SET see Single electron transfer Sharpless epoxidation, allylic alcohols, 789 Shelf durability, peroxide value, 656 Ship-in-the-bottle strategy, chiral dioxetane synthesis, 1176-7... 

The aim of the present study was to evaluate the effect of LLLT on oxidative markers in serum and tissue biopsies of healing ulcers before and after the 8th session of an LLLT course of chronic leg ulcer treatment. Oxidative damage was assessed in terms of lipid peroxidation reflected by serum malondialdehyde (MDA) level, protein oxidation was measured in terms of tissue protein carbonyls (PCb), and DNA damage was measured in terms of DNA fragmentation. Antioxidative activity was estimated by measuring activity of SOD, GPX and CAT enzymes. 

The PEG could stabilize proteins by two different temperature-dependent mechanisms. At lower temperatures, it is preferentially excluded from the protein surface but has been shown to interact with the unfolded form of the protein at higher temperatures, given its amphipathic nature (57). Thus, at lower temperatures, it may protect proteins via the mechanism of preferential exclusion, but at higher temperatures possibly by reducing the number of productive collisions between unfolded molecules. PEG is also a cryoprotectant and has been employed in Recombinate, a lyophilized formulation of recombinant Antihemophilic Factor, which utilizes PEG 3350 at a concentration of 1.5mg/mL. The low-molecular weight liquid PEGs (PEG 300-600) can be contaminated with peroxides and cause protein oxidation. If used, the peroxide content in the raw material must be minimized and controlled throughout its shelf life. The same holds true for polysorbates (discussed below). 

Numerous in vitro studies have implicated ROS in neuronal death [Leonardi and Mytilineou, 1998], and different markers of oxidative stress are found in postmortem examination of brain tissues from patients with neurodegenerative disorders [Sayre et al., 2001], DNA oxidation, protein oxidation, and lipid peroxidation have been reported in brain regions containing neurofibrillary tangles and senile plaques from Alzheimer s disease (AD) patients [Lovell and Markesbery, 2007 Polidori et al., 2007], Dopaminergic neurons in the substantia nigra of brains of Parkinson s disease (PD) patients also exhibit hallmarks of oxidative stress [Giasson et al., 2002]. 

FAEE is a potent free-radical scavenger that significantly attenuates ROS production, protein oxidation, and lipid peroxidation. 

Sultana R, Perluigi M, Butterfield DA. 2006b. Protein oxidation and lipid peroxidation in brain of subjects with Alzheimer s disease Insights into mechanism of neurodegeneration from redox proteomics. Antioxid Redox Signal 8 2021-2037. 

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