ISSN:
1052-9306
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Herein, we present the first example of charge state specific facile gas-phase cleavage of an aspartic acid-methionine peptide linkage. This cleavage (Asp 75-Met 76) was observed in the α-chain of human adult hemoglobin (Hb) and was probed by electrospray ionization mass spectrometry. This specific conformational and/or charge density dependent dissociation was observed primarily in the [M + 11H]11+ and [M + 12H]12+ species. A mechanism involving an intramolecular proton transfer from the protonated carboxyl side chain of Asp 75 to the neighboring Met 76 residue yielding an anhydride moiety at the C-terminal of the Asp 75 is proposed. Dramatic differences in dissociation of [M + 13H]13+ and [M + 14H]14+ species were observed.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200231110
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