Helicobacter pylori acid phosphatase HppA (HppA)

Helicobacter pylori acid phosphatase HppA is a 25-30 kDa surface-exposed lipoprotein that plays a vital role in the survival and pathogenesis of the bacterium within the human stomach. As a member of the class C nonspecific acid phosphohydrolase (NSAP) family and the DDDD phosphohydrolase superfamily, HppA catalyzes the hydrolysis of various phosphomonoesters, including 5'-nucleotides, with peak activity in acidic environments. Its primary biological functions include the regulation of cation flux, particularly magnesium import, and the maintenance of pH homeostasis on the bacterial cell envelope, which are essential for enduring the harsh gastric acidity. Furthermore, HppA is involved in the acquisition of critical nutrients like phosphate and heme, supporting bacterial growth and colonization. Given its surface localization and importance for virulence, HppA is a major candidate for vaccine development and a target for novel antimicrobial therapies. While no drugs are currently approved, experimental small-molecule inhibitors are being explored to disrupt its enzymatic function and impair H. pylori infection. Additionally, anti-HppA antibodies serve as significant serological biomarkers for diagnosing H. pylori-related conditions, such as chronic gastritis and peptic ulcers.

Other names

Helicobacter pylori class C acid phosphatase5'-nucleotidase HppAHP0403HppA proteinBacterial surface lipoprotein HppA

Vaccine-induced immune response; Inhibition of enzymatic activity (phosphatase and cation-flux regulation)