Arginine-specific gingipain A (RgpA) (RgpA)

Arginine-specific gingipain A (RgpA) is a major cysteine protease and virulence factor produced by the anaerobic bacterium Porphyromonas gingivalis, a keystone pathogen in chronic periodontitis [3, 8, 13]. RgpA is characterized by its ability to cleave peptide bonds specifically after arginine residues and is unique for its large molecular structure, which includes a catalytic domain and several hemagglutinin/adhesion domains that facilitate bacterial attachment to host tissues and red blood cells [11, 13, 35]. In the context of periodontal disease, RgpA contributes to tissue destruction, immune evasion by degrading cytokines and complement factors, and nutrient acquisition [1, 3, 7, 8]. Emerging research, known as the gingipain hypothesis, has also implicated RgpA in the pathogenesis of Alzheimer's disease, where it is found in the brains of patients and is thought to contribute to neuroinflammation, tau protein degradation, and amyloid-beta accumulation [1, 9, 12, 14, 15]. Therapeutic strategies targeting RgpA include small-molecule inhibitors like COR286 and peptide-based inhibitors like KYT-1, which aim to reduce bacterial load and mitigate neurodegeneration [25, 28, 30, 35, 40]. Although clinical trials for related gingipain inhibitors like atuzaginstat have faced challenges such as hepatotoxicity and missed primary endpoints, RgpA remains a significant target for treating both oral and systemic inflammatory conditions [1, 5, 6]. The inhibition of RgpA is also being explored for its potential to reduce the risk of other systemic conditions linked to P. gingivalis, such as cardiovascular disease and rheumatoid arthritis [11, 33, 41]. Overall, RgpA represents a critical link between oral health and systemic disease, offering a novel pathway for therapeutic intervention in chronic inflammatory and neurodegenerative disorders.

Other names

Gingipain R1Arg-gingipain AArginine-specific cysteine proteaseHRgpA

Cysteine protease inhibition