Alkaline modification of a Metal–Enzyme–Surfactant nanocomposite to enhance the production of L-α-glycerylphosphorylcholine

Microenvironment modification within nanoconfinement can maximize the catalytic activity of enzymes. Phospholipase A₁ (PLA₁) has been used as the biocatalyst to produce high value L-α-glycerylphosphorylcholine (L-α-GPC) through hydrolysis of phosphatidylcholine (PC). We successfully developed a simple co-precipitation method to encapsulate PLA₁ in a metal–surfactant nanocomposite (MSNC), then modified it using alkalescent 2-Methylimidazole (2-Melm) to promote catalytic efficiency in biphasic systems. The generated 2-Melm@PLA₁/MSNC showed higher catalytic activity than PLA₁/MSNC and free PLA₁. Scanning electron microscopy and transmission electron microscopy showed a typical spherical structure of 2-Melm@PLA₁/MSNC at about 50 nm, which was smaller than that of 2-Melm@MSNC. Energy disperse spectroscopy, N2 adsorption isotherms, Fourier transform infrared spectrum, and high-resolution X-ray photoelectron spectroscopy proved that 2-Melm successfully modified PLA₁/MSNC. The generated 2-Melm@PLA₁/MSNC showed a high catalytic rate per unit enzyme mass of 1.58 μmol mg^-1 min^-1 for the formation of L-α-GPC. The 2-Melm@PLA₁/MSNC also showed high thermal stability, pH stability, and reusability in a water–hexane biphasic system. The integration of alkaline and amphiphilic properties of a nanocomposite encapsulating PLA₁ resulted in highly efficient sequenced reactions of acyl migration and enzymatic hydrolysis at the interface of a biphasic system, which cannot be achieved by free enzyme.