Collision-Induced Dissociation of Cellobiose and Maltose
journal contributionposted on 2022-02-25, 16:39 authored by Hock-Seng Nguan, Shang-Ting Tsai, Chi-Kung Ni
Structure determination is a longstanding bottleneck of carbohydrate research. Tandem mass spectrometry (MS/MS) is one of the most widely used methods for carbohydrate structure determination. However, the effectiveness of MS/MS depends on how the precursor structures are derived from the observed fragments. Understanding the dissociation mechanisms is crucial for MS/MS-based structure determination. Herein, we investigate the collision-induced dissociation mechanism of β-cellobiose and β-maltose sodium adducts using quantum chemical calculations and experimental measurements. Four dissociation channels are studied. Dehydration mainly occurs through the transfer of an H atom to O1 of the sugar at the reducing end, followed by a C1–O1 bond cleavage; cross-ring dissociation starts with a ring-opening reaction, which occurs through the transfer of an H atom from O1 to O5 of the sugar at the reducing end. These two dissociation channels are analogous to that of glucose monosaccharide. The third channel, generation of B1 and Y1 ions, occurs through the transfer of an H atom from O3 (cellobiose) or O2 (maltose) to O1 of the sugar at the nonreducing end, followed by a glycosidic bond cleavage. The fourth channel, C1–Z1 fragmentation, has two mechanisms: (1) the transfer of an H atom from O3 or O2 to O4 of the sugar at the reducing end to generate C ions in the ring form and (2) the transfer of an H atom from O3 of the sugar at the reducing end to O5 of the sugar at the nonreducing end to produce C ions in the linear form. The results of calculations are supported by experimental collision-induced dissociation spectral measurements.
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widely used methodstandem mass spectrometryglycosidic bond cleavagebased structure determinationfour dissociation channelscarbohydrate structure determinationtwo dissociation channelsinduced dissociation mechanismmaltose structure determinationdehydration mainly occursproduce c ionsgenerate c ionsring dissociation starts1 </ subinduced dissociationdissociation mechanismstwo mechanismscarbohydrate researchthird channelring formreducing endprecursor structuresopening reactionobserved fragmentsnonreducing endlongstanding bottlenecklinear formh atomglucose monosaccharidefourth channelexperimental measurements