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Retracted: Isocratic Method for Affinity Enrichment of Covalently‐linked Peptides in Cyanogen Bromide Cleavage of Proteins
Author(s) -
Shi Tujin,
Liu Jing,
Yan Chen,
Wang Xiaocong
Publication year - 2011
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/pmic.201100126
Subject(s) - cyanogen bromide , covalent bond , cleavage (geology) , bromide , chemistry , proteomics , posttranslational modification , affinity chromatography , combinatorial chemistry , peptide , stereochemistry , biochemistry , peptide sequence , organic chemistry , biology , enzyme , paleontology , fracture (geology) , gene
The low resolution three-dimensional structure of a protein can be inferred from existing disulfide bridges or experimentally introduced chemical crosslinks. The general procedure involves enzymatic digestion of a protein followed by mass spectrometry-based identification of covalently-linked peptides, native disulfide-linked peptides and chemically cross-linked peptides. To facilitate unambiguous identification of these peptides, an isocratic purification method was developed for selective enrichment of covalently-linked cyanogen bromide (CNBr) fragments. This method capitalizes on the ability of homoserine lactone moieties at the C-termini of CNBr cleavage products for selective conjugation of primary-amine containing affinity tag. The availability of two C-termini within covalently-linked peptides allows for the conjugation of two affinity tags, whereas the other peptides have only one affinity tag at the C-terminus, which enables selective enrichment of covalently-linked peptides by utilization of affinity tag with moderate dissociation constant. Here we demonstrate successful implementation of this method with tetrahistidine as the affinity tag for enrichment of covalently-linked CNBr fragments of test peptides and proteins.