A novel ε-lysine acylase from Streptomyces mobaraensis for synthesis of Nε-acyl-L-lysines

A novel ε-lysine acylase (N₆-acyl-L-lysine amidohydrolase; EC 3.5.1.17) was isolated from Streptomyces mobaraensis and purified to homogeneity by SDS-PAGE from the culture broth. The purified enzyme was monomeric, with a molecular mass of approximately 60 kDa. The enzyme was inactivated by the presence of 1, 10-phenanthroline and activated in the presence of Co²⁺ and Zn²⁺. The enzyme showed a pH optimum of 8.0 and was stable at temperatures of up to 50°C for 1 h at pH 8.0. The enzyme specifically catalyzed the hydrolysis of the amide bond of various Nε-acyl-L-lysines. Furthermore, the enzyme efficiently catalyzed the synthesis of Nε-acyl-L-lysines with fatty and aromatic acyl groups in an aqueous buffer. In the syntheses of Nε-decanoyl-L-lysine, Nε-lauroyl-L-lysine, and Nε-myristoyl-L-lysine, the product precipitated and the yield was 90% or higher using 10 mM FA and 0.5 M L-lysine as the substrate.