title: Novel pyridinium-based tags: synthesis and characterization for highly efficient analysis of thiol-containing peptides by mass spectrometry.
abstract: In this study, a novel type of pyridinium-based tags, 1-[3-[(2-iodo-1-oxoethyl)amino]propyl]-4-methylpyridinium bromide (IMP) and 1-[3-[(2-iodo-1-oxoethyl)amino]propyl]-4-propylpyridinium bromide (IPP), were designed, synthesized, and applied to the derivatization of thiol-containing peptides. With model peptides as the sample, the labeling efficiency and the stability of the peptide derivatives were investigated. The results indicate that nearly 100% derivatization yield was achieved with the developed tags and the peptide derivatives were stable at room temperature for at least one week. Furthermore, improved ionization efficiency and increased charge states were achieved via both matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS) and electrospray ionization (ESI) MS, of which IPP exhibited the more obvious improvement of ionization efficiency. Further analysis of tryptic digests of bovine serum albumin (BSA) and α-transferrin, showed that increased identification efficiency of the thiol-containing peptides was achieved by combination with IMP or IPP derivatization. For example, the identification efficiency of the thiol-containing peptides of α-transferrin increased more than 42% upon combination with the IMP or IPP derivatives. We anticipate the novel tags are promising for highly efficient thiol-containing peptide identification in proteome research, especially for low concentrations.
authors.affiliation: Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education and Key Laboratory of Pharmaceutical Quality Control of Hebei Province, College of Pharmaceutical Sciences, Hebei University, Baoding 071002, China. xiaoqiao@hbu.edu.cn yangxun_0@163.com.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Qiao
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Yang
authors.forename: Shijia
authors.initials: S
authors.lastname: Liu
authors.forename: Shiheng
authors.initials: S
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Guangyue
authors.initials: G
authors.lastname: Li
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Yan
authors.forename: Xun
authors.initials: X
authors.lastname: Yang
mesh_terms: D006842:Hydrocarbons, Brominated / Q000138:chemical synthesis / Q000737:chemistry; D010455:Peptides / Q000032:analysis; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000032:analysis* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000032:analysis; D014168:Transferrin / Q000032:analysis* / Q000378:metabolism
chemical_list: C000601207:1-(3-((2-iodo-1-oxoethyl)amino)propyl)-4-methylpyridinium bromide; C000601209:1-(3-((2-iodo-1-oxoethyl)amino)propyl)-4-propylpyridinium bromide; D006842:Hydrocarbons, Brominated; D010455:Peptides; D011726:Pyridinium Compounds; D013438:Sulfhydryl Compounds; D014168:Transferrin; D012710:Serum Albumin, Bovine