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Identification of incompletely processed potential Carboxypeptidase E substrates from CpE fat /CpE fat mice
Author(s) -
Bures Edward J.,
Courchesne Paul L.,
Douglass James,
Chen Kui,
Davis Michael T.,
Jones Michael D.,
McGinley Michael D.,
Robinson John H.,
Spahr Chris S.,
Sun Jilin,
Wahl Robert C.,
Patterson Scott D.
Publication year - 2001
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/1615-9861(200101)1:1<79::aid-prot79>3.0.co;2-8
Subject(s) - peptide , carboxypeptidase , chemistry , neuropeptide , biochemistry , mass spectrometry , tandem mass spectrometry , prohormone , exopeptidase , chromatography , microbiology and biotechnology , biology , enzyme , receptor , hormone
In an attempt to identify peptides that may be involved in the obese phenotype observed in CpE fat /CpE fat mice (deficient in Carboxypeptidase E, CpE) samples from fourteen neuroendocrine tissues in wild‐type and CpE fat /CpE fat mice were obtained. Peptides were purified from these tissues and potential CpE substrate peptides were enriched using an anhydrotrypsin column that captures peptides with basic C‐termini. Bound peptides were subjected to tryptic digestion and followed by liquid chromatography‐mass spectrometry analysis. The relative levels of CpE fat /CpE fat versus wild‐type peptides were determined by comparison of the ion intensities. Peptide ions elevated in the CpE fat /CpE fat samples were identified by targeted liquid chromatography‐tandem mass spectrometry. From those ions, 27 peptides derived from known neuropeptides (including CpE substrates) were identified, together with another 25 peptides from proteins not known to be components of the neuropeptide processing pathway. The known CpE substrates identified included the recently discovered proSAAS, granin‐like neuroendocrine peptide precursor that inhibits prohormone processing. The approach demonstrated the feasibility of using an affinity‐based method for identifying differences in specific classes of peptides between normal and mutant mice.