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Tandem mass spectrometric analysis of 13 C‐containing ions from a mixture of homologous peptides differing by one mass unit at a residue
Author(s) -
Wada Y.,
Hisada M.,
Kaneko R.,
Naoki H.,
Matsuo T.
Publication year - 2000
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/(sici)1096-9888(200002)35:2<242::aid-jms935>3.0.co;2-e
Subject(s) - chemistry , tandem mass spectrometry , peptide , mass spectrometry , fragmentation (computing) , ion , collision induced dissociation , protein mass spectrometry , peptide sequence , amino acid , chromatography , biochemistry , organic chemistry , computer science , operating system , gene
Tandem mass spectrometry of a mixture of two peptides that differ from each other by a single mass unit due to mutation is presented. The mutant β ‐globin of hemoglobin Hoshida is present along with the normal counterpart, and the amino acid substitution of glutamine for glutamic acid is located within tryptic peptide T5 of M r 2057.9. The mass of the mutated peptide is 1 u lower. In the isotopic cluster for the doubly charged ion of the peptide T5, the resolved ion with mass of 1030.0 represents the normal peptide with 93 12 C atoms and the mutated one with 92 12 C and one 13 C atoms. Collision‐induced dissociation (CID) of this composite ion identified the mutation by presenting a key fragment derived from the 12 C‐only mutant peptide, as reported in a previous study. Similarly, when an ion containing multiple 13 C atoms was selected as a precursor for CID, the mutation could be identified, even in large fragments, by a marked change in the shape of the isotopic cluster for the consecutive product ions. This study demonstrates the merit of selecting a resolved ion rather than the whole isotopic cluster as a precursor in the CID measurements of large peptides or proteins for characterizing heterozygous mutations. Copyright © 2000 John Wiley & Sons, Ltd.