Yuan Dongjuan, Lan Dongming, Xin Ruipu, Yang Bo, Wang Yonghua
College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
Int J Mol Sci. 2014 Jun 12;15(6):10554-66. doi: 10.3390/ijms150610554.
Mono- and di-acylglycerol lipase has been applied to industrial usage in oil modification for its special substrate selectivity. Until now, the reported mono- and di-acylglycerol lipases from microorganism are limited, and there is no report on the mono- and di-acylglycerol lipase from bacteria. A predicted lipase (named MAJ1) from marine Janibacter sp. strain HTCC2649 was purified and biochemical characterized. MAJ1 was clustered in the family I.7 of esterase/lipase. The optimum activity of the purified MAJ1 occurred at pH 7.0 and 30 °C. The enzyme retained 50% of the optimum activity at 5 °C, indicating that MAJ1 is a cold-active lipase. The enzyme activity was stable in the presence of various metal ions, and inhibited in EDTA. MAJ1 was resistant to detergents. MAJ1 preferentially hydrolyzed mono- and di-acylglycerols, but did not show activity to triacylglycerols of camellia oil substrates. Further, MAJ1 is low homologous to that of the reported fungal diacylglycerol lipases, including Malassezia globosa lipase 1 (SMG1), Penicillium camembertii lipase U-150 (PCL), and Aspergillus oryzae lipase (AOL). Thus, we identified a novel cold-active bacterial lipase with a sn-1/3 preference towards mono- and di-acylglycerides for the first time. Moreover, it has the potential, in oil modification, for special substrate selectivity.
单酰甘油脂肪酶和二酰甘油脂肪酶因其特殊的底物选择性已被应用于油脂改性的工业用途。到目前为止，已报道的微生物来源的单酰甘油脂肪酶和二酰甘油脂肪酶数量有限，且尚无来自细菌的单酰甘油脂肪酶和二酰甘油脂肪酶的相关报道。从海洋詹氏菌属菌株HTCC2649中纯化出一种预测的脂肪酶（命名为MAJ1）并对其进行了生化特性分析。MAJ1属于酯酶/脂肪酶家族I.7。纯化后的MAJ1的最佳活性出现在pH 7.0和30℃条件下。该酶在5℃时仍保留50%的最佳活性，表明MAJ1是一种冷活性脂肪酶。在各种金属离子存在的情况下，该酶活性稳定，而在EDTA中受到抑制。MAJ1对洗涤剂具有抗性。MAJ1优先水解单酰甘油和二酰甘油，但对山茶油底物的三酰甘油没有活性。此外，MAJ1与已报道的真菌二酰甘油脂肪酶，包括球形马拉色菌脂肪酶1（SMG1）、卡门柏青霉脂肪酶U-150（PCL）和米曲霉脂肪酶（AOL）的同源性较低。因此，我们首次鉴定出一种新型的冷活性细菌脂肪酶，它对单酰甘油和二酰甘油具有sn-1/3偏好性。此外，它在油脂改性方面具有特殊底物选择性的潜力。
