Sequencing of a branched peptide using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
Chemical degradation methods combined with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and post-source decay (PSD)-MALDI reflex TOF mass spectrometry (MS) were used to determine the sequence of a peptide branched on to a known peptide backbone. This study was applied to a branched peptide model (derivative of substance P). The branched peptide mimics a digest of a membrane receptor on to which a derivative of substance P was photochemically linked. Chemical degradation based on N-terminal ladder sequencing in combination with MALDI-TOF-MS gave only partial sequence information. Although single PSD mass spectra still remain difficult to interpret unambiguously, PSD-MALDI-TOF-MS was combined with on-target acetylation and H -- D exchange to give a better and successful approach to the unambiguous determination of the complete amino acid side-chain sequence. This study shows the capability of MALDI-TOF-MS to help in characterizing ligand-receptor interactions.
Fournier
I
I
Laboratoire de Chimie Structurale Organique et Biologique, Université P & M. Curie, CNRS UMR 7613, Bât. F, Boite 45, 4 place Jussieu, F-75252 Paris, France.
Chaurand
P
P
Bolbach
G
G
Lützenkirchen
F
F
Spengler
B
B
Tabet
J C
JC
D000107:Acetylation; D000595:Amino Acid Sequence; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D010777:Photochemistry; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013373:Substance P / Q000737:chemistry
D010455:Peptides; D013373:Substance P