Secreted aspartic protease 2 (SAP2) (SAP2)

Secreted aspartic protease 2 (SAP2), also known as Candidapepsin-2, is a major extracellular virulence factor produced by the opportunistic fungal pathogen Candida albicans [1, 3]. It belongs to a family of ten secreted aspartyl proteinases (SAPs) that play a critical role in the fungus's ability to colonize, invade, and damage host tissues during both mucosal and systemic infections [2, 6]. SAP2 exhibits broad substrate specificity, degrading a variety of host proteins including keratin, collagen, and albumin to provide nutrients for fungal growth [1, 7]. Furthermore, it facilitates immune evasion by cleaving host defense molecules such as immunoglobulins (IgA, IgG, IgM), complement factors, and antimicrobial peptides like histatin-5 [3, 6]. Due to its central role in pathogenesis, SAP2 is a significant therapeutic target; its activity can be inhibited by aspartic protease inhibitors like Pepstatin A and certain HIV protease inhibitors (e.g., Ritonavir, Saquinavir), which have been observed to reduce the severity of candidiasis in clinical settings [2, 6]. Additionally, SAP2 has been utilized as an antigen in the development of recombinant vaccines, such as PEV7, which has undergone clinical trials to prevent recurrent vulvovaginal candidiasis [4].

Other names

Candidapepsin-2ACP 2Aspartate protease 2Secreted aspartyl proteinase 2Pepsinogen-11PEP11PRA11

Inhibition of the catalytic activity of the aspartic protease to prevent the degradation of host structural and immune proteins, thereby reducing fungal virulence and tissue invasion [2, 6].