Degradation of N-acylhomoserine lactones, the bacterial quorum-sensing molecules, by acylase

Abstract

Porcine kidney acylase I was shown to be able to deacylate N-acylhomoserine lactones, a family of chemicals employed by Gram-negative bacteria as quorum-sensing molecules for cell population density-dependent growth (such as biofilm formation). The enzyme transformed both N-butyryl-and N-octanoyl- l-homoserine lactones into l-homoserine. An optimal pH of 10 at 23 °C and an optimal temperature of 76 °C at pH 9 were found for the enzyme in hydrolyzing N-butyryl-homoserine lactone. At pH 9 and 23 °C, the enzymatic catalysis had a K m of 81±3 mM and a k cat of 127±2 nmol min −1 per mg. The enzyme was also shown to be able to reduce the biofilm growth in an aquarium water sample. Potential physiological significance and medicinal/industrial applications of the N-acylhomoserine lactone-degrading activity of acylase are discussed.