Inactivation of chosen dehydrogenases by the products of water radiolysis and secondary albumin and haemoglobin radicals

Abstract

In the light of these results and literature data, the observed differences in the effectiveness of inactivation of the dehydrogenases studied by secondary protein radicals depend on the amino acid residues present at the active site and in its close neighborhood and on the number of amino acid residues available on the protein surface.

Efficiency of superoxide anions in the inactivation of selected dehydrogenases

“…Alcohol dehydrogenase is less sensitive (Table 1, system 1). A similar order of sensitivity of the studied dehydrogenases under air was obtained in the previous work (Kowalczyk et al, 2008). …”

“…Most products of water radiolysis do not directly react with amino acid residues occurring in the active site, but with those available at the surface of the molecule. Increased enzyme inactivation may then occur as a consequence of radical transfer from protein surface to the active site area (as discussed in the work by Kowalczyk et al 2008). Although the size of dehydrogenases and their surface areas are similar, they differ in their surface structures expressed as the number of accessible amino acid residues (on the basis of Swiss-PDB Viewer program).…”

Free Radicals Induced Oxidative Stress at a Molecular Level: The Current Status, Challenges and Perspectives of Computational Chemistry Based Protocols

“…[256] First of all, the repairing enzymes are also susceptible to be damaged by OS, losing their function as a result of this damage. [257][258][259][260][261][262] In addition, when their action may be needed the most, i.e., during illness and aging, the enzymatic repairing activity is decreased. [263] Finally, but not less important, is the fact that the half-lives of DNA radicals are dramatically shorter than the enzymatic repairing processes.…”

A model of interactions between radiation-induced oxidative stress, protein and DNA damage in Deinococcus radiodurans

“…When sensitive sites on proteins involved in DNA repair and replication are oxidized by radiation-induced reactive oxygen and nitrogen species (ROS and RNS), the activity and fidelity of these proteins are altered, which may impede correct repair of DNA damage such as DSBs, enhancing cell death and mutagenesis (Adams et al, 1979; Bisby et al, 1982; Culard et al, 2003; Daly, 2009; Daly et al, 2007; Eon et al, 2001; Ghosal et al, 2005; Goodhead and Nikjoo, 1987; Kowalczyk et al, 2008; Saha et al, 1992). Such phenomena probably occur to some extent even at relatively low doses of radiation/oxidative stress (e.g.…”

“…(Montaner et al, 2007)). However, they are easiest to investigate at high doses, where both DNA and protein damage are extensive (Adams et al, 1979; Bisby et al, 1982; Culard et al, 2003; Eon et al, 2001; Gerard et al, 2001; Goodhead and Nikjoo, 1987; Jolivet et al, 2006; Kowalczyk et al, 2008; Liu et al, 2003; Zahradka et al, 2006; Zimmermann et al, 1994), and interactions between them are probably most pronounced.…”