Acylation of Amino Acids by Aminoacylase in Non-Conventional Media

N-Acylation of amino acids by aminoacylase (EC 3.5.1.14) isolated from pig kidney was investigated. In water containing organic solutions native aminoacylase proved to be unsuitable for acylation reactions. Covalent immobilization enhanced the stability of aminoacylase in organic solvents (dimethylformamide and dioxane). The support gel beads showed extraordinary swelling behaviour in dimethylformamide solutions of different water content with respect to their liquid uptake and the temperature sensitivity of swelling. N-Acylation activity of immobilized enzyme proved to be sufficient in case of L-methionine as substrate and acetate as acylating agent. In addition, the peptide (Ala-Ala) formation was unambiguous but the reaction was much slower than acylation under the given conditions.