title: Enrichment of peptides containing consensus sequence by an enzymatic approach for targeted analysis of proteins.
abstract: Multiple residues with consensus sequence, i.e. motif, on proteins are closely related to protein function. However, there is no effective method for targeted analysis of such proteins. The challenge for analysis of these classes of proteins by MS is how to selectively enrich peptides containing consensus sequence from protein digest. Although enrichment of peptides containing one type of amino acid residue was successfully achieved by chemically labeling followed by chromatographic isolation, however, it is almost impossible to label and isolate signature peptides containing multiple residues with consensus sequence by chemical approach. Herein, we developed an enzymatic approach based on the specific recognition between enzyme and its substrates to enrich such peptides. This approach was realized by modification of a residue in the consensus sequence via enzyme that can recognize the sequence followed by the isolation of the modified peptides. cAMP-dependent protein kinase was used to validate this approach and 168 peptides containing consensus motif were identified with selectivity of 67.2%. Those peptides resulted in the identification of 88 proteins with consensus sequence from serum sample. As this motif-oriented peptide enrichment approach allows targeted analysis of a subset of proteins with consensus sequence, it will have broad application in biological studies.
authors.affiliation: Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P R China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Wang
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Guanghui
authors.initials: G
authors.lastname: Han
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.forename: Manyu
authors.initials: M
authors.lastname: Zhang
authors.forename: Xinning
authors.initials: X
authors.lastname: Jiang
authors.forename: Kai
authors.initials: K
authors.lastname: Cheng
authors.forename: Fangjun
authors.initials: F
authors.lastname: Wang
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D016384:Consensus Sequence; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000302:isolation & purification* / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D001798:Blood Proteins; D010455:Peptides; D017868:Cyclic AMP-Dependent Protein Kinases