Charge-Directed Peptide Backbone Dissociations of o-TEMPO-Bz-C(O)-Peptides

• Published in: Mass spectrometry letters Vol. 4; no. 4; pp. 71 - 74
• Main Authors: Aeran Jeon, Ji Hye Lee, Hyuk Su Kwon, Hyung Soon Park, Bong Jin Moon, Han Bin Oh
• Format: Journal Article
• Language: English
• Published: 한국질량분석학회 01.12.2013; 사단법인 한국질량분석학회
• Subjects: 화학; Charge-directed dissociations; Radical chemistry; Free radical initiated peptide sequencing; Mobile proton model; Peptide
• ISSN: 2233-4203; 2093-8950
• DOI: 10.5478/MSL.2013.4.4.71

In the present study, we report that the charge-directed (assisted) peptide dissociation products, such as b- and y-type peptidebackbone fragments, were the major products in MS/MS and MS3 applications of some o-TEMPO-Bz-C(O)-peptide ions, whileradical-driven dissociation products, such as a/x and c/z-type fragments, were previously shown to be the major products in the freeradical initiated peptide sequencing mass spectrometry (FRIPS MS). Those o-TEMPO-Bz-C(O)-peptides share a common feature intheir sequences, that is, the peptides do not include an arginine residue that has the highest proton affinity among free amino acids. The appearance of b- and y-type fragments as major products in FRIPS MS can be understood in terms of the so-called “mobile-protonmodel”. When the proton is highly mobilized by the absence of arginine, the chare-directed peptide dissociation pathways appearto be more competitive than the radical-driven dissociation pathways, in our FRIPS experiments. KCI Citation Count: 1