title: N (α) Selective Acetylation of Peptides.
abstract: A chemical tag at the peptide N-terminus, in combination with MS, can be useful for quantitative analysis, N-terminal peptide identification, or peptide sequencing. Here we report on the N (α) selective acetylation of a peptide using acetic anhydride, a popular reagent for the modification of amino groups, without the need for the blocking of lysine side-chain ε-amino groups, which is usually required for N (α) selective acetylation. By controlling the amount of acetic anhydride used and running the reaction at 0°C, it is possible to preferentially acetylate the α-amino group. As a typical application of the method, a tryptic digest of an N-terminally blocked protein, cytochrome c, was directly acetylated using the present method. When deuterated acetic anhydride was used as the reagent, the N-terminal blocked peptide could be easily identified as a non-labeled ion peak while the N (α)-acetyl groups of all the other peptides were deuterated.
authors.affiliation: Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Mikami
authors.affiliation: Laboratory of Protein Profiling and Functional Proteomics, Institute for Protein Research, Osaka University.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Takao
authors.affiliation: Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yanagi
authors.affiliation: Pharmaceutical Business Division, Sumika Chemical Analysis Service, Ltd.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakazawa
keywords: acetylation; isotope-labeling; peptide; protein