Membranes within an animal are composed of phospholipids, cholesterol, and proteins that together form a dynamic barrier. The types of lipids that are found within a membrane bilayer impact its biophysical properties including its fluidity, permeability, and susceptibility to damage. While membrane composition is very stable in healthy adults, aberrant membrane structure is seen in a wide and varied array of diseases as well as during natural aging. Despite the wide-reaching impacts of membrane composition, there is relatively little known about how membrane landscape is established and maintained over time. In vivo biochemical modeling of membrane lipids is needed to understand how these molecules interact in their natural configurations. Here, we have described analytical methods that increase the capacity to map the dynamics of individual membrane phospholipids using different types of mass spectrometry. Specifically, we describe novel stable isotope (¹³C and ¹⁵N) strategies to quantify the turnover of dozens of fatty acid tails and intact phospholipids simultaneously.

动物体内的膜由磷脂、胆固醇和蛋白质组成，它们共同形成一个动态屏障。在膜双层中发现的脂质类型会影响其生物物理特性，包括其流动性、渗透性和对损坏的敏感性。虽然膜成分在健康成年人中非常稳定，但在各种疾病以及自然衰老过程中都可以看到异常的膜结构。尽管膜组成具有广泛的影响，但人们对膜景观如何随着时间的推移而建立和维持的了解相对较少。体内需要对膜脂进行生化建模，以了解这些分子在其自然构型中如何相互作用。在这里，我们描述了使用不同类型的质谱法提高绘制单个膜磷脂动态的能力的分析方法。具体来说，我们描述了新的稳定同位素（¹³ C 和¹⁵ N）策略，以同时量化数十个脂肪酸尾部和完整磷脂的周转。