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

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 degrees C and an optimal temperature of 76 degrees C at pH 9 were found for the enzyme in hydrolyzing N-butyryl-homoserine lactone. At pH 9 and 23 degrees 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.