4d73

Publication Abstract from PubMed

Life under aerobic conditions has shaped peroxiredoxins (Prx) as ubiquitous thiol-dependent hydroperoxidases and redox-sensors. Structural features that balance the catalytically active or inactive redox states of Prx, and, therefore, their hydroperoxidase or sensor function, have so far been analyzed predominantly for Prx1-type enzymes. Here we identify and characterize two modulatory residues of the Prx5-type model enzyme PfAOP from the malaria parasite Plasmodium falciparum. Gain- and loss-of-function mutants reveal a correlation between the enzyme parameters as well as the inactivation susceptibility of PfAOP with the size of residue 109 and the presence or absence of a catalytically relevant but non-essential cysteine residue. Based on our kinetic data and the crystal structure of PfAOPL109M, we suggest a novel mechanism for balancing the hydroperoxidase activity and inactivation susceptibility of Prx5-type enzymes. Our study provides unexpected insights into Prx structure-function relationships and contributes to our understanding of what makes Prx good enzymes or redox-sensors.

Plasmodium falciparum antioxidant protein reveals a novel mechanism for balancing turnover and inactivation of peroxiredoxins.,Staudacher V, Djuika CF, Koduka J, Schlossarek S, Kopp J, Buchler M, Lanzer M, Deponte M Free Radic Biol Med. 2015 May 4. pii: S0891-5849(15)00193-8. doi:, 10.1016/j.freeradbiomed.2015.04.030. PMID:25952724^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.