- Tytuł:
- Does the peroxidase-like activity of sodium dodecyl sulphate-modified cytochrome c increase after peroxynitrite or radiation treatment?.
- Autorzy:
-
Gębicka, Lidia
Didik, Joanna - Powiązania:
- https://bibliotekanauki.pl/articles/1041449.pdf
- Data publikacji:
- 2005
- Wydawca:
- Polskie Towarzystwo Biochemiczne
- Tematy:
-
cytochrome c
peroxynitrite; radiation
SDS
peroxidatic activity - Opis:
- The peroxidase-like activity of cytochrome c is considerably increased by unfolding of the protein. The enhancement of the activity is due to the higher reaction rate of unfolded cytochrome c with hydrogen peroxide, which is the rate-determining step in the peroxidase cycle of cytochrome c (Gębicka, L., 2001, Res Chem Intermed 27, 717-23). In this study we checked whether combined action of two unfolding factors, SDS and peroxynitrite or radiation (hydroxyl radicals), increases the peroxidase-like activity of cytochrome c more than any single treatment alone. Peroxynitrite reacts with SDS-modified cytochrome c in the same way as with native cytochrome c, via intermediate radical products, •OH/•NO2, arising from peroxynitrite homolysis. We found that SDS-modified cytochrome c is much more sensitive to oxidative damage than the native protein. Partial unfolding of cytochrome c by SDS causes the peroxide substrate to have a better access to the heme center. On the other hand, the amino acids located in the vicinity of the active site and/or heme group become accessible for oxidizing radicals. The overall effect observed is that the peroxidase-like activity of SDS-modified cytochrome c decreases with an increase of the concentration of the oxidizing species (peroxynitrite or radiolytically generated hydroxyl radicals). The damage of SDS-modified cytochrome c caused by irradiation is much more significant than that observed after peroxynitrite treatment.
- Źródło:
-
Acta Biochimica Polonica; 2005, 52, 2; 551-555
0001-527X - Pojawia się w:
- Acta Biochimica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł