A novel ∈‐lysine acylase from Streptomyces mobaraensis for synthesis of N∈ ‐acyl‐ l ‐lysines

A novel ∈‐lysine acylase ( N 6 ‐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 Co 2+ and Zn 2+ . 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 N ∈‐acyl‐ l ‐lysines. Furthermore, the enzyme efficiently catalyzed the synthesis of N ∈‐acyl‐ l ‐lysines with fatty and aromatic acyl groups in an aqueous buffer. In the syntheses of N ∈‐decanoyl‐ l ‐lysine, N ∈‐lauroyl‐ l ‐lysine, and N ∈‐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.