title: N-phosphorylation labeling for analysis of twenty natural amino acids and small peptides by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
abstract: N-phosphorylation labeling was utilized to analyze the low molecular weight compounds by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A wide range of natural amino acids and short peptides was successfully analyzed by MALDI-TOF MS without matrix background interferences. The N-phosphorylation labeling reaction was carried out easily within 30 min in a one-pot reaction under mild reaction conditions. The phosphoryl derivatization reaction is a global labeling approach with high selectivity and high specificity with targeting only on the N-terminal and ε-amino group of Lys. The incorporation of a neutral phosphoryl group with high gas-phase affinity of protons not only improves the ionization efficiency of target molecules and simultaneously decreases the ion suppression effects in MALDI-TOF MS analysis, but also greatly reduces or eliminates the matrix background interferences by suppressing the matrix signals and increasing the molecular weight of the targeted compounds. By applying the N-phosphorylation labeling approach, many amino acids could be detected in serum samples by using MALDI-TOF MS.
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, SAR, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Xin
authors.initials: X
authors.lastname: Bi
authors.forename: Juntong
authors.initials: J
authors.lastname: Wei
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Peng
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000097:blood; D010455:Peptides / Q000032:analysis*; D010766:Phosphorylation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000596:Amino Acids; D010455:Peptides