Physics Department, Kent State University, Kent, OH 44242, United States.
Physics Department, Kent State University, Kent, OH 44242, United States.
Biochim Biophys Acta Biomembr. 2018 Feb;1860(2):396-406. doi: 10.1016/j.bbamem.2017.10.008. Epub 2017 Oct 10.
Lipid droplets are "small" organelles that play an important role in de novo synthesis of new membrane, and steroid hormones, as well as in energy storage. The way proteins interact specifically with the oil-(phospho-)lipid monolayer interface of lipid droplets is a relatively unexplored but crucial question. Here, we use our home built liquid droplet tensiometer to mimic intracellular lipid droplets and study protein-lipid interactions at this interface. As model neutral lipid binding protein, we use apoLp-III, an amphipathic α-helix bundle protein. This domain is also found in proteins from the perilipin family and in apoE. Protein binding to the monolayer is studied by the decrease in the oil/water surface tension. Previous work used POPC (one of the major lipids found on lipid droplets) to form the phospholipid monolayer on the triolein surface. Here we expand this work by incorporating other lipids with different physico-chemical properties to study the effect of charge and lipid head-group size. This study sheds light on the affinity of this important protein domain to interact with lipids.
脂滴是“小”细胞器，在新膜和类固醇激素的从头合成中以及在能量储存中发挥重要作用。蛋白质与脂滴的油-(磷酸-)脂质单层界面特异性相互作用的方式是一个相对未被探索但至关重要的问题。在这里，我们使用我们自己构建的液滴张力计来模拟细胞内的脂滴，并在该界面研究蛋白质-脂质相互作用。作为模型中性脂质结合蛋白，我们使用 apoLp-III，一种两亲性α-螺旋束蛋白。该结构域也存在于 perilipin 家族的蛋白质和 apoE 中。通过降低油/水表面张力来研究蛋白质与单层的结合。以前的工作使用 POPC（脂滴上发现的主要脂质之一）在三油酸甘油酯表面形成磷脂单层。在这里，我们通过掺入具有不同物理化学性质的其他脂质来扩展这项工作，以研究电荷和脂质头部基团大小的影响。这项研究阐明了这个重要蛋白质结构域与脂质相互作用的亲和力。
