Glutaryl-7-ACA acylase catalyses the synthesis of amide bond in heterogeneous substrate mixtures

Covalently immobilised glutaryl acylase (GA), used in industry for the hydrolysis of glutaryl-7-aminocephalosporanic acid, was employed for the first time in low-water media. Results indicate that the enzyme catalyses the synthesis of the amide bond when working at very high substrate concentrations, namely in heterogeneous substrate mixtures, whereas no enzymatic activity was detected using the enzyme in diluted organic solvent solutions. Preliminary data on GA substrate selectivity suggest that a negative charge on the acyl moiety is crucial for substrate recognition.