[Redox properties of peptides potentially regulating animal hibernation]

Weak redox properties of peptides isolated from the brain of hibernating animals were determined in reactions with free radicals. The peptides Thr-Ser-Lys-Tyr-Arg (NKT) and Tyr-Arg diminished concentration of anion-radicals of dye excited by light, thus demonstrating electron-acceptor properties toward radicals. In contrast, the peptides Thr-Ser-Lys-Tyr (RZ-5) and Asp-Tyr acted as electron donors in the same radical reactions. The possible role of redox properties of these peptides in their regulation of Ca currents in excitable tissues is discussed.