Ma Xuejing, Zhi Zelun, Zhang Shuyan, Zhou Chang, Mechler Adam, Liu Pingsheng
National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
iScience. 2021 Jul 10;24(8):102834. doi: 10.1016/j.isci.2021.102834. eCollection 2021 Aug 20.
New strategies are urgently needed to characterize the functions of the lipid droplet (LD). Here, adiposome, an artificial LD mimetic platform, was validated by comparative bioassays. Scatchard analysis found that the binding of perilipin 2 (PLIN2) to the adiposome surface was saturable. Phosphatidylinositol (PtdIns) was found to inhibit PLIN2 binding while it did not impede perilipin 3 (PLIN3). Structural analysis combined with mutagenesis revealed that the 73 glutamic acid of PLIN2 is significant for the effect of PtdIns on the PLIN2 binding. Furthermore, adiposome was also found to be an ideal platform for enzymatic activity measurement of adipose triglyceride lipase (ATGL). The significant serine mutants of ATGL were found to cause the loss of lipase activity. Our study demonstrates the adiposome as a powerful, manipulatable model system that mimics the function of LD for binding and enzymatic activity studies of LD proteins .
迫切需要新的策略来表征脂滴（LD）的功能。在这里，通过比较生物测定法验证了脂肪体，一种人工LD模拟平台。Scatchard分析发现， perilipin 2（PLIN2）与脂肪体表面的结合是可饱和的。发现磷脂酰肌醇（PtdIns）可抑制PLIN2结合，而不影响perilipin 3（PLIN3）。结构分析与诱变相结合表明，PLIN2的73位谷氨酸对PtdIns对PLIN2结合的影响具有重要意义。此外，还发现脂肪体是测量脂肪甘油三酯脂肪酶（ATGL）酶活性的理想平台。发现ATGL的重要丝氨酸突变体导致脂肪酶活性丧失。我们的研究表明，脂肪体是一种强大的、可操纵的模型系统，可模拟LD的功能，用于LD蛋白的结合和酶活性研究。
