Neuropeptide Y (NPY) is a transmitter molecule in nerve system, and it was an over 4‐kDa large peptide with the C‐terminal end amidation. NPY is biosynthesized through many maturation processes from a large pre‐pro‐peptide with peptide‐cleavages and amidation that is important to study the biosynthesis regulation. Previously, it was reported that cathepsin L participates in the production of NPY and that cathepsin L generates both of amidated and non‐amidated NPYs. However, the non‐amidated NPY (NPY‐COOH) has not been reported in brain tissues until now. In this study, endogenous NPY‐COOH in mouse brain tissue was detected and identified by using nano flow liquid chromatography (nanoLC) orbitrap Fourier transform mass spectrometry (FT‐MS) after the effective purification and separation of NPY‐COOH from NPY‐amide and other peptides using two different gel‐filtration chromatography. Amidated NPY was eluted earlier than non‐amidated NPY‐COOH in the C18 reversed phase nanoLC and the silica‐based gel‐filtration chromatogram with hydrophobic interaction. The amount of endogenous NPY‐COOH was about 0.05% of the matured NPY‐amide amount in adult mouse brain.

中文翻译：

---

纳流液相色谱轨道阱傅里叶变换质谱法对脑组织中内源性神经肽Y进行酰胺化/非酰胺化自上而下分析


神经肽Y（NPY）是神经系统中的递质分子，是一种C端酰胺化的超过4-kDa的大肽。 NPY 是通过许多成熟过程从具有肽裂解和酰胺化的大型前肽原中生物合成的，这对于研究生物合成调控非常重要。此前有报道称组织蛋白酶 L 参与 NPY 的产生，并且组织蛋白酶 L 产生酰胺化和非酰胺化 NPY。然而，迄今为止，尚未有关于脑组织中非酰胺化 NPY (NPY-COOH) 的报道。本研究通过纳流液相色谱（nanoLC）轨道阱傅里叶变换质谱（FT-MS）对小鼠脑组织中的内源性NPY-COOH进行有效纯化和分离，从NPY-酰胺和NPY-COOH中进行有效纯化和分离。使用两种不同的凝胶过滤色谱法分析其他肽。在 C18 反相 nanoLC 和具有疏水相互作用的硅胶基凝胶过滤色谱中，酰胺化 NPY 比非酰胺化 NPY-COOH 更早洗脱。成年小鼠脑中内源性 NPY-COOH 的量约为成熟 NPY-酰胺量的 0.05%。