Internal residue loss produced by rearrangement of a novel cationic glycosphingolipid, glyceroplasmalopsychosine, in collision-induced dissociation.
Internal residue loss produced by rearrangement of a novel cationic glycosphingolipid, glyceroplasmalopsychosine, in collision-induced dissociation.
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在碰撞诱导解离中，新型阳离子鞘糖脂甘油胞浆菌素重排产生的内部残基损失。
DOI：
10.1002/jms.485
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Ishizuka,Ineo
中科院分区：
文献类型：
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作者：
Tadano-Aritomi,Keiko;Hikita,Toshiyuki;Kubota,Masayuki;Kasama,Takeshi;Toma,Kazunori;Hakomori,Sen-Itiroh;Ishizuka,Ineo
采用电喷雾电离和液体二次离子质谱结合低能或高能碰撞诱导解离（CID）分析了一种新型的半乳糖基鞘氨醇（psychosine）的血浆结合物Gro 1（3）-O-血浆-O-6 Gal β-鞘氨醇（甘油血浆鞘氨醇）。在[M + H]+离子的产物离子谱中，由甘油的损失产生的[M + H-甘油]+离子占优势。出乎意料的是，[M + H-甘油]+离子的CID产生了一个突出的离子[（M + H-甘油）-Hex]+，这需要从分子内部损失半乳糖。该离子在N，N-二甲基衍生物的光谱中大大减少，表明[（M + H-甘油）-Hex]+离子是由分子内重排形成的，血浆残基迁移到鞘氨醇的游离氨基。预计重排与甘油的消除同时发生，或者重排的[M + H]+离子导致甘油的消除，形成希夫碱型[M + H-甘油]+离子，其中末端半乳糖可以通过糖苷切割的正常机制被去除。另一方面，来自钠化分子的[M + Na − glycerol]+离子没有产生对应于重排反应的离子，这可能是由于钠化离子对构象变化的稳定性更高。版权所有© 2003年约翰威利父子有限公司。
A novel plasmal conjugate of galactosylsphingosine (psychosine), Gro1(3)‐O‐plasmal‐O‐6Galβ‐sphingosine (glyceroplasmalopsychosine), was analyzed by electrospray ionization and liquid secondary ion mass spectrometry with low‐ or high‐energy collision‐induced dissociation (CID). In the product ion spectra of the [M + H]+ions, [M + H − glycerol]+ions arising from the loss of a glycerol were predominant. Unexpectedly, CID of the [M + H − glycerol]+ion produced an outstanding ion, [(M + H − glycerol) − Hex]+, which required the loss of the galactose from inside the molecule. This ion was greatly reduced in the spectra ofN,N‐dimethyl derivatives, indicating that the [(M + H − glycerol) − Hex]+ion is formed from an intramolecular rearrangement with migration of the plasmal residue to the free amino group of sphingosine. It would be expected that the rearrangement occurs simultaneously with the elimination of glycerol or a rearranged [M + H]+ion leads to the elimination of glycerol, to form a Schiff base‐type [M + H − glycerol]+ion, from which the terminal galactose could be removed by the normal mechanism of glycosidic cleavage. On the other hand, the [M + Na − glycerol]+ion derived from the sodiated molecule did not produce an ion corresponding to the rearrangement reaction, possibly owing to a higher stability of the sodiated ions against conformational changes. Copyright © 2003 John Wiley & Sons, Ltd.