In Vivo Characterization of Endogeneous Neuropeptides and -proteins on a Chromatographic Time-scale using Nanoflow LC/FTICR-MS/MS

摘要

We present here a targeted proteomics approach where immunoprecipitation using antibodies is combined with nanoflow liquid chromatography and FTICR tandem mass spectrometry. Two different new groups of endogeneous APP fragments from human cerebrospinal fluid have been discovered and identified. The first group of fragments all end at amino acid 15 in the Amyloid-beta sequence but differ N-teminally. They may reflect a novel metabolic parthway for APP and A(beta). The other group are N-terminal APP fragments of size approx12 kDa, which may represent a previously unknown metabolic processing pathway for APP. alpha-synuclein from human brain extract has been detected and identified. This protein also exists in several isoforms.