Medium-and long-chain triglycerides(MLCT)rich in arachidonic acid(ARA)were synthesized via acidolysis of microbial oil(MO)with caprylic acid(CA)using bio-imprinted lipase(BIL)as a catalyst.The optimal preparation cond...Medium-and long-chain triglycerides(MLCT)rich in arachidonic acid(ARA)were synthesized via acidolysis of microbial oil(MO)with caprylic acid(CA)using bio-imprinted lipase(BIL)as a catalyst.The optimal preparation conditions for bio-imprinting were as follows:Lipozyme RM IM as the catalyst,CA as the bio-imprinting template at a concentration of 6 mg/mL,Tween 20 at 15 mg/mL,and a buffer pH of 7.Under these conditions,the initial activity of BIL was 1.99 times higher than that of the non-bioimprinted enzyme.Thermodynamic analysis showed a decrease in activation energy from 26.46 kJ/mol to 18.08 kJ/mol after bio-imprinting.The molecular docking results revealed that the imprinted template(CA)interacted with Ser-161 of Lipozyme RM IM via a hydrogen bond,and its binding was further stabilized through additional hydrogen bonding and hydrophobic interactions,thereby enhancing the enzyme's catalytic activity.Bio-imprinting had a lower binding energy and bound more tightly to substrates with shorter carbon chain lengths.The optimal conditions for MLCT synthesis were:BIL 8 wt%,60℃,CA/MO molar ratio of 2:1 and reaction time 4 h.The maximum incorporation rate of CA achieved was 27.82 mol%,and the contents of sn-2 ARA and sn-1,3CA in MLCT were 34.20 mol%and 37.44 mol%,respectively.These findings could contribute to advancing MLCT production and deepening the under-standing of the catalytic mechanism of lipase-mediated acidolysis reactions.展开更多
基金supported by the National Natural Science Foundation of China(31601433)。
文摘Medium-and long-chain triglycerides(MLCT)rich in arachidonic acid(ARA)were synthesized via acidolysis of microbial oil(MO)with caprylic acid(CA)using bio-imprinted lipase(BIL)as a catalyst.The optimal preparation conditions for bio-imprinting were as follows:Lipozyme RM IM as the catalyst,CA as the bio-imprinting template at a concentration of 6 mg/mL,Tween 20 at 15 mg/mL,and a buffer pH of 7.Under these conditions,the initial activity of BIL was 1.99 times higher than that of the non-bioimprinted enzyme.Thermodynamic analysis showed a decrease in activation energy from 26.46 kJ/mol to 18.08 kJ/mol after bio-imprinting.The molecular docking results revealed that the imprinted template(CA)interacted with Ser-161 of Lipozyme RM IM via a hydrogen bond,and its binding was further stabilized through additional hydrogen bonding and hydrophobic interactions,thereby enhancing the enzyme's catalytic activity.Bio-imprinting had a lower binding energy and bound more tightly to substrates with shorter carbon chain lengths.The optimal conditions for MLCT synthesis were:BIL 8 wt%,60℃,CA/MO molar ratio of 2:1 and reaction time 4 h.The maximum incorporation rate of CA achieved was 27.82 mol%,and the contents of sn-2 ARA and sn-1,3CA in MLCT were 34.20 mol%and 37.44 mol%,respectively.These findings could contribute to advancing MLCT production and deepening the under-standing of the catalytic mechanism of lipase-mediated acidolysis reactions.
