Peroxidases are enzymes that break down hydrogen peroxide in organisms. Since their discovery in 1998, the electron source of "peroxiredoxin 6-type" peroxidases for this reaction remained unclear. The research group of Professor Marcel Deponte at RPTU has now closed this knowledge gap. The researchers demonstrated in two model organisms—humans and malaria pathogens—that peroxiredoxin 6-type enzymes react rapidly with hydrosulfide, the anion of hydrogen sulfide. The study was published in the journal Advanced Science. The findings reveal a previously unknown connection between peroxide and sulfide metabolism.