A strategy for rapid and efficient sequencing of Lys-C peptides by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry post-source decay.
A modification procedure for Lys-C peptides is described which simplifies the correct assignment of the amino acid sequence. Release of the C-terminal lysine from Lys-C peptides by carboxypeptidase B and subsequent N-terminal acetylation of the resulting peptides leads to predictable shifts of the C- and N-terminal fragment ions in Matrix-assisted laser desorption/ionisation time-of-flight post-source decay mass spectra and facilitates the correct assignment of mostly complete amino acid sequences for oligopeptides. The derived sequences of peptides from unknown proteins were used to search in databases for homologous protein sequences. Our method was applied to an unknown protein isolated from eggs of Drosophila melanogaster, resulting in the identification of a peptidyl prolyl cis-trans-isomerase.
Pfeifer
T
T
Max-Planck Research Unit Enzymology of Protein Folding, Halle/Saale, Germany.
Rücknagel
P
P
Kuellertz
G
G
Schierhorn
A
A
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D043424:Carboxypeptidase B; D002268:Carboxypeptidases; D002851:Chromatography, High Pressure Liquid; D016208:Databases, Factual; D004331:Drosophila melanogaster; D006868:Hydrolysis; D008239:Lysine / Q000737:chemistry*; D008969:Molecular Sequence Data; D010063:Ovum / Q000737:chemistry; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
D010455:Peptides; D002268:Carboxypeptidases; D043424:Carboxypeptidase B; D008239:Lysine