Outer membrane phospholipase A (OMPLA)

Helicobacter pylori outer membrane phospholipase A (OMPLA), also known as PldA, is a critical enzyme and virulence factor located in the bacterial outer membrane (Vollan et al., 2017; Dorrell et al., 1999). Its primary biological function is the hydrolysis of phospholipids into lysophospholipids and fatty acids, which helps the bacterium acquire nutrients and destabilize the host's gastric mucus barrier (Nih.gov, 1.1.2; PMC, 1.1.5). OMPLA also functions as a transmembrane pore that facilitates the transport of urea and ammonium, playing a vital role in the bacterium's ability to survive the acidic environment of the stomach (Vollan et al., 2017; Springer, 1.1.4). In terms of pathogenesis, the enzyme contributes to mucosal damage, inflammation, and the eventual development of peptic ulcers and gastric adenocarcinoma (PMC, 1.1.5; Nih.gov, 1.2.2). It has been shown to modulate host immune responses by disrupting macrophage signaling pathways, such as TNFR1, thereby promoting bacterial persistence (Nih.gov, 1.2.2; Gut Microbes, 2024). OMPLA is considered a therapeutic target because its inhibition can reduce bacterial colonization and protect the gastric lining (Dorrell et al., 1999; Nih.gov, 1.2.2). Bismuth-containing drugs, such as bismuth subsalicylate and colloidal bismuth subcitrate, are known to interact with and inhibit OMPLA activity by competing with calcium ions for the enzyme's active site (Slomiany et al., 1992). Targeting OMPLA is particularly relevant for treating multidrug-resistant H. pylori strains, as it offers a mechanism of action distinct from traditional antibiotics (Nih.gov, 1.2.2; Gut Microbes, 2024).

Other names

PldAPhospholipase AHP0499Helicobacter pylori phospholipase AExtracellular phospholipase A

Inhibition of phospholipase A2 activity through competition with calcium ions for the enzyme's active site (Slomiany et al., 1992)