47 kDa membrane antigen (Treponema pallidum) (Tpp47)

The 47 kDa membrane antigen of Treponema pallidum, commonly referred to as Tpp47 or Tp47, is the most abundant and immunodominant lipoprotein of the spirochete that causes syphilis (UniProt P29723). It serves as a novel penicillin-binding protein (PBP) and possesses zinc-dependent D,D-carboxypeptidase activity, which is vital for the synthesis and maintenance of the bacterial peptidoglycan layer (Deka et al., 2002; Weigel et al., 1994). Tpp47 is highly conserved across Treponema strains and is expressed constitutively, making it a reliable target for both diagnostic testing and potential vaccine development (Frontiers in Immunology, 2021). In clinical practice, it is a key component of treponemal serological tests and is the primary target for molecular detection via PCR of the tp0574 gene (Journal of Clinical Microbiology, 2009). Although it exhibits an unusual beta-lactamase-like activity capable of hydrolyzing penicillins, the protein remains a primary target for beta-lactam antibiotics like penicillin G, which bind covalently to its active site (Deka et al., 2002). Its unique structural architecture, featuring a predominantly beta-sheet fold, distinguishes it from classical PBPs found in other bacteria and may contribute to the pathogen's ability to persist within the host (RCSB PDB 1O75). Understanding the interaction between Tpp47 and beta-lactams is crucial for monitoring the potential emergence of antibiotic resistance in syphilis (Frontiers in Medicine, 2022).

Other names

Tpp47Tp47TpN47TP057447 kDa lipoproteinMajor integral membrane immunogen

Covalent binding and inhibition of penicillin-binding protein activity, interfering with peptidoglycan cross-linking