Identification of unusual (modified and non-encoded) amino acid residues in peptides by combinations of high-performance liquid chromatography and high-performance capillary electrophoresis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry

The techniques for micro-level analysis of some widespread unusual amino ac ids (phosphorylated and hydroxylated ones) as well as of some genetically n on-encoded amino acids were developed for their subsequent identification i n the peptide and protein amino acid sequence by narrow-bore column high-pe rformance liquid chromatography (similar to 10 pmol of the sample), high-pe rformance capillary electrophoresis (similar to 1-10 pmol), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (similar to 1 -10 pmol), and automatic protein gas phase sequencing (similar to 1-50 pmol ). (C) 2000 Elsevier Science B.V. All rights reserved.