Catalase: A repertoire of unusual features

Abstract

Catalases are antioxidant enzymes which catalyze the breakdown of hydrogen peroxide to water and oxygen, and are one of the oldest enzymes to be studied biochemically. The first crystal structure of a catalase appeared in the year 1980 and it revealed the tetrameric nature of the enzyme and presence of channels accessing the deeply buried active site heine. An interesting feature of the tetrameric structure is the characteristic interweaving or arm exchange of the subunits. The recent elucidation of the crystal structure of transport proteins (porins, aquaporins) showed that these proteins are also tetrameric in nature and posses channels. However, recent specific investigations focusing on the roles for these channels, in the mechanism of enzyme action of catalases, revealed significant similarities with that observed for the transport of water and/or glycerol, in aquaporins.

Reactive oxygen species detoxification by catalase is a major determinant of fecundity in the mosquito Anopheles gambiae

“…3 B-D). A common property of catalases is that the N-and C-terminal ends of each monomeric subunit overlap, or ''interweave'' with other catalase monomers in the formation of a catalytically active tetramer (23,24). The N terminus affects tetramer formation; in Candida tropicans catalase (27) and E. coli catalase (28), small N terminus deletions (4-and 18-aa, respectively) reduce tetrameric accumulation.…”

“…The N terminus of catalases is regarded as important in the formation of catalase tetramers (23,24). A silver-stained native gel showed that the Ser allele consisted almost entirely of the tetrameric form, whereas the equilibrium for the subunit asso- ciation in the Trp allele was significantly shifted to a smaller form (Fig.…”

Butyric acid-induced rat jugular blood cytosolic oxidative stress is associated with SIRT1 decrease

“…1b-d, respectively) which would imply that BA retention in the gingival tissue induces oxidative stress in the blood cytosol and is correlated to heme accumulation. Heme is a biomolecule that interacts with various apo-proteins giving rise to functional heme-proteins which include antioxidant (Chelikani et al 2005) and pro-oxidant (Espinosa et al 2009) enzymes. Build-up in cytosolic reactive oxygen species (ROS), like H 2 O 2 , triggers mitochondrial oxidative stress (Doughan et al 2008), whereas elevated mitochondrial ROS activates NADPH oxidase (Wosniak et al 2009).…”

Alkaliphilic bacteria: applications in industrial biotechnology

“…The ROS are formed due to incomplete reduction of oxygen [254]. One type of ROS produced due to aerobic respiratory processes is hydrogen peroxide (H 2 O 2 ) [46]. Such oxidants can cause damage to lipids, proteins, and nucleic acids.…”