Garden R W, Moroz T P, Gleeson J M, Floyd P D, Li L, Rubakhin S S, Sweedler J V
Department of Chemistry and Beckman Institute, University of Illinois, Urbana 61801, USA.
J Neurochem. 1999 Feb;72(2):676-81. doi: 10.1046/j.1471-4159.1999.0720676.x.
Matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry is used to examine the formation of N-pyroglutamate (pGlu) in single, identified neurons from Aplysia. Six pGlu peptides are identified in the R3-14 and the R15 neurons that result from in vivo processing of peptides containing either Glu or Gln at their respective N-termini. Moreover, we show that Glu-derived pGlu is not a sample collection or measurement artifact. The pGlu peptides are detected in isolated cell bodies, regenerated neurites in culture, interganglionic connective nerves, cell homogenates, and collected releasates. We also demonstrate that R3-14 cells readily convert a synthetic N-Glu peptide to its pGlu analogue, indicating the presence of novel enzymatic activity.
基质辅助激光解吸/电离飞行时间质谱法用于检测海兔单个已鉴定神经元中N-焦谷氨酸（pGlu）的形成。在R3-14和R15神经元中鉴定出六种pGlu肽，它们是由各自N端含有Glu或Gln的肽在体内加工产生的。此外，我们表明源自Glu的pGlu不是样本收集或测量假象。在分离的细胞体、培养中再生的神经突、神经节间结缔神经、细胞匀浆和收集的释放物中检测到pGlu肽。我们还证明R3-14细胞很容易将合成的N-Glu肽转化为其pGlu类似物，表明存在新的酶活性。
