title: Sequence analysis of phosphoserine-containing peptides. Modification for picomolar sensitivity.
abstract: Sequencing of phosphoserine-containing peptides yields normally no identifiable PTH-derivatives at those positions where phosphoserine is located. Here a new method is described which allows identification of the position of phosphoserine by chemical modification just before sequence analysis. In a one-step microbatch reaction, phosphoserine present in the intact peptide can be transformed quantitatively into stable derivatives such as beta-methylaminoalanine (MAA), S-ethanolcysteine or S-ethylcysteine. These derivatives are detectable during microsequencing with less than 100 pmol peptide using an Applied Biosystems gas-phase sequencer equipped with an on-line PTH amino acid analyzer.
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D008832:Microchemistry; D009842:Oligopeptides / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis*; D010768:Phosphoserine / Q000032:analysis*; D012694:Serine / Q000031:analogs & derivatives*
chemical_list: D009842:Oligopeptides; D010750:Phosphoproteins; D010768:Phosphoserine; D012694:Serine; C037642:kemptide