Facile assignment of sequence ions of a peptide labelled with 18O at the carboxyl terminus.
The combination of collision-induced dissociation (CID) and linked-scan analysis was used for analysing the sequence ions from the precursor ion of a peptide, which had been labelled with 18O at its carboxyl terminus (C-terminus) using 40 atom % H2 18O. The CID and linked-scan mass spectrum of the labelled peptide gave two series of sequence-ion signals: the one, originating from the C-terminus of the labelled peptide, showed a doublet signal due to the part-incorporation of 18O into the carboxyl group at the C-terminus, while the other, originating from the amino terminus (N-terminus), has the natural isotopic ion distribution. From the distribution of the isotopic ions in a single CID spectrum, the sequence ions containing the C-terminus could be readily differentiated from those containing the N-terminus, allowing the facile assignment of sequence ions to the amino-acid sequence of a peptide by CID and linked-scan analysis. This method was successfully applied to determination of the amino-acid sequence of the light-chain of mouse anti-porphyrin monoclonal antibody.
Takao
T
T
Institute for Protein Research, Osaka University, Japan.
Hori
H
H
Okamoto
K
K
Harada
A
A
Kamachi
M
M
Shimonishi
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D006868:Hydrolysis; D051379:Mice; D008969:Molecular Sequence Data; D010104:Oxygen Radioisotopes; D010455:Peptides / Q000032:analysis*; D011166:Porphyrins / Q000276:immunology; D016339:Spectrometry, Mass, Fast Atom Bombardment
D000911:Antibodies, Monoclonal; D010104:Oxygen Radioisotopes; D010455:Peptides; D011166:Porphyrins