Abstract：
Customization of deuterated biomolecules is vital for many advanced biological experiments including neutron scattering. However, because it is challenging to control the proportion and regiospecificity of deuterium incorporation in live systems, often only two or three synthetic lipids are mixed together to form simplistic model membranes. This limits the applicability and biological accuracy of the results generated with these synthetic membranes. Despite some limited prior examination of deuterating Escherichia coli lipids in vivo, this approach has not been widely implemented. Here, an extensive mass spectrometry-based profiling of E. coli phospholipid deuteration states with several different growth media was performed, and a computational method to describe deuterium distributions with a one-number summary is introduced. The deuteration states of 36 lipid species were quantitatively profiled in 15 different growth conditions, and tandem mass spectrometry was used to reveal deuterium localization. Regressions were employed to enable the prediction of lipid deuteration for untested conditions. Small-angle neutron scattering was performed on select deuterated lipid samples, which validated the deuteration states calculated from the mass spectral data. Based on these experiments, guidelines for the design of specifically deuterated phospholipids are described. This unlocks even greater capabilities from neutron-based techniques, enabling experiments that were formerly impossible.
摘要：
氘代生物分子的定制对于包括中子散射在内的许多高级生物实验至关重要。然而,因为控制活系统中氘掺入的比例和区域特异性具有挑战性，通常只有两种或三种合成脂质混合在一起形成简单的模型膜。这限制了用这些合成膜产生的结果的适用性和生物学准确性。尽管先前对体内氘代大肠杆菌脂质的检查有限，这种方法尚未得到广泛实施。这里,使用几种不同的生长培养基对大肠杆菌磷脂氘代状态进行了广泛的基于质谱的分析，并介绍了用一个数字摘要描述氘分布的计算方法。在15种不同的生长条件下，对36种脂质的氘代状态进行了定量分析，串联质谱法用于揭示氘的定位。采用回归来预测未测试条件下的脂质氘代。对选择的氘代脂质样品进行了小角度中子散射，这验证了从质谱数据计算的氘代状态。基于这些实验,描述了特定氘代磷脂的设计指南。这从基于中子的技术中释放了更大的能力，实现以前不可能的实验。
