Penicillin Acylase from Streptomyces lavendulae and Aculeacin A Acylase from Actinoplanes utahensis: Two Versatile Enzymes as Useful Tools for Quorum Quenching Processes

Abstract

Many Gram-negative bacteria produceN-acyl-homoserine lactones (AHLs), quorum sensing(QS) molecules that can be enzymatically inactivated by quorum quenching (QQ) processes; this approachis considered an emerging antimicrobial alternative. In this study, kinetic parameters of several AHLshydrolyzed by penicillin acylase fromStreptomyces lavendulae(SlPA) and aculeacin A acylase fromActinoplanes utahensis(AuAAC) have been determined. Both enzymes catalyze efficiently the amide bondhydrolysis in AHLs with different acyl chain moieties (with or without 3-oxo modification) and exhibit aclear preference for AHLs with long acyl chains (C12-HSL>C14-HSL>C10-HSL>C8-HSL forSlPA,whereas C14-HSL>C12-HSL>C10-HSL>C8-HSL forAuAAC). Involvement ofSlPA andAuAAC inQQ processes was demonstrated byChromobacterium violaceumCV026-based bioassays and inhibitionof biofilm formation byPseudomonas aeruginosa, a process controlled by QS molecules, suggesting theapplication of these multifunctional enzymes as quorum quenching agents, this being the first time thatquorum quenching activity was shown by an aculeacin A acylase. In addition, a phylogenetic studysuggests thatSlPA andAuAAC could be part of a new family of actinomycete acylases, with a preferencefor substrates with long aliphatic acyl chains, and likely involved in QQ processes.