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Selective extraction of peptides in acidic human plasma by porous silica nanoparticles for peptidome analysis with 2‐D LC‐MS/MS
Author(s) -
Tian Ruijun,
Ye Mingliang,
Hu Lianghai,
Li Xin,
Zou Hanfa
Publication year - 2007
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200700156
Subject(s) - chemistry , chromatography , peptide , sample preparation , human plasma , extraction (chemistry) , cleavage (geology) , nanoparticle , biochemistry , nanotechnology , materials science , geotechnical engineering , fracture (geology) , engineering
In this study, an improved method for human plasma peptidome analysis including selective porous silica nanoparticles (MCM‐41) extraction and subsequent online 2‐D nano‐LC‐MS/MS analysis was established. Enhanced enrichment efficiency for the MCM‐41 extraction was obtained by adjusting the pH of the plasma sample to 2.5. A total of 1680 unique peptides were identified in the plasma sample obtained from one healthy donor, which is nearly twice the amount identified from the native state of the plasma sample. The hydrophobic property, molecular weight (MW), and p I distribution of the identified peptides at pH 2.5 and native state of the plasma sample were systematically investigated and compared. Furthermore, many unusual cleaved peptides from plasma proteins ( e. g. , HSA) were observed at pH 2.5, which clearly show a ladder pattern. The cleavage patterns for all of the identified peptides at pH 2.5 were summarized, and chymosin and cathepsin D were confirmed as the possible peptidases responsible for the change of cleavage pattern in peptide profiling.