Related Experiment Video
Updated: May 31, 2026
Super-resolution Imaging of Proteus mirabilis Biofilm by Expansion Microscopy
Published on: July 18, 2025
Comprehensive inhibitor profiling of the Proteus mirabilis metalloprotease virulence factor ZapA (mirabilysin)
Louise Carson1, George R Cathcart, Christopher J Scott
1School of Pharmacy, Queens University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
Abstract:
In this study we report for the first time the comprehensive inhibitor profiling of the Proteus mirabilis metalloprotease virulence factor ZapA (mirabilysin) using a 160 compound focused library of N-alpha mercaptoamide dipeptides, in order to map the S(1)(') and S(2)(') binding site preferences of this important enzyme. This study has revealed a preference for the aromatic residues tyrosine and tryptophan in P(1)(') and aliphatic residues in P(2)('). From this library, six compounds were identified which exhibited sub- to low-micromolar K(i) values. The most potent inactivator, SH-CO(2)-Y-V-NH(2) was capable of preventing ZapA-mediated hydrolysis of heat-denatured IgA, indicating that these inhibitors may be capable of protecting host proteins against ZapA during colonisation and infection.
Insights
Researchers profiled inhibitors for Proteus mirabilis metalloprotease ZapA, identifying potent compounds targeting its binding sites. These ZapA inhibitors show potential for protecting host proteins during infection.
Area of Science:
- Microbiology
- Enzymology
- Drug Discovery
Background:
- Proteus mirabilis is an opportunistic pathogen associated with urinary tract infections.
- The metalloprotease ZapA (mirabilysin) is a key virulence factor of P. mirabilis.
- Understanding ZapA's active site is crucial for developing targeted inhibitors.
Purpose of the Study:
- To perform comprehensive inhibitor profiling of ZapA.
- To map the S(1)(') and S(2)(') binding site preferences of ZapA.
- To identify potent inhibitors of ZapA activity.
Main Methods:
- Utilized a focused library of 160 N-alpha mercaptoamide dipeptides for inhibitor screening.
- Determined enzyme kinetics to assess inhibitor potency (K(i) values).
- Evaluated inhibitor efficacy in preventing ZapA-mediated hydrolysis of IgA.
Main Results:
- ZapA exhibits a preference for aromatic residues (tyrosine, tryptophan) in the P(1)(') site and aliphatic residues in the P(2)(') site.
- Six compounds demonstrated sub- to low-micromolar inhibition constants (K(i)).
- The most potent inhibitor, SH-CO(2)-Y-V-NH(2), effectively blocked ZapA's hydrolysis of IgA.
Conclusions:
- N-alpha mercaptoamide dipeptides are effective inhibitors of ZapA.
- The identified inhibitors target specific binding pockets within ZapA.
- These ZapA inhibitors hold promise for therapeutic strategies against P. mirabilis infections.
