Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Nat Methods. 2021 Oct;18(10):1233-1238. doi: 10.1038/s41592-021-01277-2. Epub 2021 Sep 30.
Peptidergic dense-core vesicles are involved in packaging and releasing neuropeptides and peptide hormones-critical processes underlying brain, endocrine and exocrine function. Yet, the heterogeneity within these organelles, even for morphologically defined vesicle types, is not well characterized because of their small volumes. We present image-guided, high-throughput mass spectrometry-based protocols to chemically profile large populations of both dense-core vesicles and lucent vesicles for their lipid and peptide contents, allowing observation of the chemical heterogeneity within and between these two vesicle populations. The proteolytic processing products of four prohormones are observed within the dense-core vesicles, and the mass spectral features corresponding to the specific peptide products suggest three distinct dense-core vesicle populations. Notable differences in the lipid mass range are observed between the dense-core and lucent vesicles. These single-organelle mass spectrometry approaches are adaptable to characterize a range of subcellular structures.
肽能致密核心囊泡参与神经肽和肽类激素的包装和释放——这些是脑、内分泌和外分泌功能的基础。然而，由于这些细胞器体积小，即使对于形态上定义明确的囊泡类型，其内部的异质性也没有得到很好的描述。我们提出了基于图像引导的高通量质谱方法，用于对大量致密核心囊泡和透明囊泡的脂质和肽含量进行化学分析，从而可以观察到这两种囊泡群体内部和之间的化学异质性。在致密核心囊泡中观察到了四种前激素的蛋白水解加工产物，并且与特定肽产物相对应的质谱特征表明存在三种不同的致密核心囊泡群体。在致密核心囊泡和透明囊泡之间观察到脂质质量范围的显著差异。这些单细胞质谱方法可以适应于对一系列亚细胞结构进行特征描述。
