Novel biochemical aspects of lugdulysin, a Staphylococcus lugdunensis metalloprotease that inhibits formation and disrupts protein biofilm of methicillin-resistant Staphylococcus aureus.

Abstract

Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modeling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37 °C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition, and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 h. Lugdulysin significantly inhibited the formation and disrupted preestablished protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.