Substrate profiling of Finegoldia magna SufA protease, inhibitor screening and application to prevent human fibrinogen degradation and bacteria growth in vitro.
Burchacka. Ewa E; Sieńczyk. Marcin M; Frick. Inga-Maria IM; Wysocka. Magdalena M; Lesner. Adam A; Oleksyszyn. Józef J
Key Findings
- SufA enzyme degrades LL‑37 and fibrinogen, weakening host defenses
- The enzyme prefers certain amino‑acid sequences in its substrates (identified via FRET)
- A phosphonic‑acid‑based inhibitor (Cbz‑6‑AmNphth(P)(OPh)2) effectively blocks SufA and shows antibacterial activity
Practical Outcomes
- For DIY health enthusiasts, the study shows that SufA can neutralize LL‑37, so taking LL‑37 supplements might be less effective if this bacterial enzyme is present. The identified inhibitor is still experimental and not available for personal use, so there’s no immediate protocol to apply. However, the work highlights the importance of protecting LL‑37 from bacterial proteases, suggesting future research may yield supplements or topical agents that block SufA.
Summary
The bacteria Finegoldia magna makes an enzyme called SufA that can cut up the human antimicrobial peptide LL‑37 and also break down fibrinogen, which may help the bacteria spread. Researchers mapped which protein pieces SufA likes to cut and found a chemical (Cbz‑6‑AmNphth(P)(OPh)2) that can block the enzyme. This blocker stopped SufA from destroying fibrinogen in lab tests and also killed several bacteria, including F. magna, Staph aureus and E. coli.
Abstract
SufA, which belongs to the subtilisin-like serine protease family, contains a non-canonical Asp-His-Ser catalytic triad. Under in vitro conditions, SufA is capable of human fibrinogen hydrolysis leading to inhibition of fibrin network formation, thus suggesting its important role in the development and progression of Finegoldia magna infections. In addition, it has been demonstrated that SufA can hydrolyze antibacterial peptides such as LL-37 and the chemokine MIG/CXCL 9, hence evading host defence mechanisms. Although the SufA protease from F. magna was discovered several years ago, its optimal substrate preference has not yet been identified. Considering the role of SufA, we have focused on the profiling of its substrate sequence preference spanning S1-S3 binding pockets using the FRET (fluorescence resonance energy transfer) approach. Next, based on the structure of the P1 residue of the developed substrate, we narrowed the inhibitor screening to the phosphonic analogues of amino acids containing an arginine-like side chain. Among all the compounds tested, only Cbz-6-AmNphth(P)(OPh)2 showed any inhibitory activity against SufA displaying k2/Ki value of 10,800 M(-1) s(-1). In addition, it prevented SufA-mediated human fibrinogen hydrolysis in vitro and exhibited potent antibacterial activity against F. magna, Staphylococcus aureus and Escherichia coli. Herein, we report on the substrate specificity, synthesis and kinetic evaluation of phosphonic inhibitors of SufA protease from F. magna which could help to establish its function in pathogenesis development and may lead to the elaboration of new antibacterial drugs.
Study Information
pubmed
2014
2014-05-22T00:00:00.000Z
10.1016/j.biochi.2014.05.006
9
38