Evaluation the selectivity of three lipases in the synthesis of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol, an asymmetric triacylglycerol

1-Oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) is the most abundant triacylglycerol (TAG) molecule in Chinese human milk. The selectivity of three lipases including Rhizomucor miehei lipase (RML), Thermomyces lanuginose lipase (TL), and Candida antarctica lipase (CALB) in OPL synthesis were evaluated. The effects of different reaction conditions on selectivity were first investigated. Unexpectedly, the three sn-1,3 regioselectivity lipases, also have selectivity for the structure of product TAGs. Compared with symmetric TAGs, lipases had poor selectivity toward asymmetric OPL. Furthermore, molecular simulations were used to deeply understand the molecular factors affecting lipase selectivity. The results showed that hydrophobic interactions, lipases lid domain flexibility, and the stability of hydrogen bonds between lipases and TAGs were the main molecular factors responsible for the selectivity of lipases.