Helicobacter pylori catalase (KatA)

Helicobacter pylori catalase (KatA) is a vital heme-containing antioxidant enzyme that enables the pathogen to survive the oxidative stress encountered in the human gastric environment [1, 2]. Its primary function is the catalytic decomposition of hydrogen peroxide into water and oxygen, which protects the bacterium from reactive oxygen species (ROS) generated by its own metabolism and the host's immune response, particularly the oxidative burst from neutrophils [4, 5]. Distinct from most other catalases, KatA possesses a high isoelectric point (pI 9.0–9.3) and utilizes methionine residues for the non-enzymatic quenching of hypochlorous acid (HOCl) [2, 4]. Furthermore, KatA has been identified as a cholesterol-binding protein that aids in the acquisition of host lipids for the bacterial membrane [8]. As an essential virulence factor for colonization and persistence, KatA is considered a high-priority target for the development of vaccines and novel therapeutic inhibitors to combat antibiotic-resistant strains of H. pylori [6, 13].

Other names

KatAHP0875Hydrogen-peroxide:hydrogen-peroxide oxidoreductase

The enzyme catalyzes the dismutation of hydrogen peroxide into water and oxygen, quenches hypochlorous acid via methionine residues, and facilitates the binding and transport of host cholesterol through CARC and CRAC domains.