Insight into the human pathodegradome of the V8 protease from Staphylococcus aureus

Abstract

SUMMARY Staphylococcus aureus possesses ten extracellular proteases with mostly unknown targets in the human proteome. To assist with bacterial protease target discovery, we have applied and compared two N-terminomics methods to investigate cleavage of human serum proteins by S. aureus V8 protease, discovering 85 host-protein targets. Among these are virulence-relevant complement, iron sequestration, clotting cascade, and host protease inhibitor proteins. Protein cleavage sites have been identified, providing insight into the disruption of host protein function by V8. Complement proteins are cleaved within peptidase and sushi domains, and host protease inhibitors are cleaved outside their protease-trapping motifs. Our data highlight the potential for further application of N-terminomics in discovery of bacterial protease substrates in other host niches and provide omics-scale insight into the role of the V8 protease in S. aureus pathogenesis.

Peptidomic analysis of endogenous and bacterial protease activity in human plasma and wound fluids

“… 29 , 30 , 31 , 32 For LasB and V8, we found respectively 145 and 142 protein targets not detected in the control plasma samples, whereas these numbers were 155 for LasB and 180 for V8 in wound fluids. A recent report using N-terminomics revealed the detection of 85 host-protein targets of V8 in human serum, 17 many of which we identified here with our peptidomics approach as well, thereby showing the validity of our methods and results. Nevertheless, we cannot exclude that some of the identified proteins are actually generated by other proteases present as proenzymes in the original samples, as proteases are known to release active proteases from their precursors.…”

“… 13 , 14 , 15 The presence of bacteria impairs wound repair by the release of among others virulence factors such as bacterial proteases that degrade host proteins, thereby damaging the fragile regenerating wound bed. For instance, the metalloprotease P. aeruginosa elastase B (LasB) and the S. aureus serine protease V8 (SspA) both cleave extracellular matrix components such as fibronectin, 16 vitronectin, 16 , 17 and laminin α3 LG4-5, 18 as well as inhibitors of endogenous proteases, 17 , 19 , 20 thereby enhancing proteolytic activity even further. Moreover, bacterial proteases may influence endogenous proteases directly and work in synergy to amplify the hostile wound environment.…”

Dual-Modal Cellular Nanoparticles for Continuous Neurotoxin Detoxification

“…We conducted a similar study using V8 as a model exogenous protease. 28 The study showed similar results; free SxtN retained 45.2 ± 2.8% of its enzymatic activity, whereas Neuron-MOF/SxtN-NPs preserved approximately 91.2 ± 7.7% of the initial enzymatic activity following V8 treatment (Figure 2B). These findings validate our hypothesis that the nanoparticle formulation can effectively shield the SxtN payload from protease degradation.…”

“…In contrast, Neuron-MOF/SxtN-NPs retained approximately 91.0 ± 3.6% of the SxtN enzymatic activity after trypsin treatment. We conducted a similar study using V8 as a model exogenous protease . The study showed similar results; free SxtN retained 45.2 ± 2.8% of its enzymatic activity, whereas Neuron-MOF/SxtN-NPs preserved approximately 91.2 ± 7.7% of the initial enzymatic activity following V8 treatment (Figure B).…”