Purification and enzymatic assay of BmaI1, a quorum sensing signal synthase

Abstract

Quorum sensing is a bacterial cell‐cell communication system that functions through the synthesis, secretion, and detection of signaling molecules called autoinducers. Quorum sensing enables bacteria to assess their cell density and coordinate group behaviors that are advantageous at high cell density. Many bacteria that cause acute and chronic infections in humans use quorum sensing to control expression of virulence factors and formation of biofilms, so inhibitors of quorum sensing hold significant promise as novel antibacterial agents. By targeting bacterial virulence as opposed to growth and survival, quorum sensing inhibitors avoid the selective pressure for drug resistance that is inherent to traditional antibiotics.The main quorum sensing system in Gram‐negative bacteria is based on the synthesis and detection of acyl homoserine lactone (AHL) autoinducers. Efforts to inhibit AHL‐mediated quorum sensing have focused on developing synthetic AHL analogs that act as antagonists of AHL receptors. These compounds have been shown to block virulence controlled by quorum sensing, validating quorum sensing as an antibacterial drug target.The overall goal of the project is to develop inhibitors of AHL synthase enzymes, an alternative quorum sensing drug target that remains under‐explored. Towards this goal, we cloned and purified BmaI1, an AHL synthase from Burkholderia mallei. AHL synthases use S‐adenosyl methionine and acylated ACP protein as substrates. Generating Acyl‐ACP requires purification of ACP, and several sequential enzymatic modifications to make it suitable as an AHL synthase substrate. We have developed a small, synthetic substitute for acyl ACP that is utilized by BmaI1, avoiding the difficult and time‐consuming production of acyl‐ACP.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.