Lam-Thanh H, Deprun C, Le Beyec Y
Service de Biochimie, CEN, Saclay, Gif-sur-Yvette, France.
Rapid Commun Mass Spectrom. 1990 Feb;4(2):41-3. doi: 10.1002/rcm.1290040202.
The molecular weights of four linear synthetic peptides, fragments of a snake alpha-neurotoxin, were measured by 252Cf-plasma desorption mass spectrometry. The fragmentation phenomenon observed at the level of serine and/or threonine residue with a concomitant ion/fragment association is reported for a group of two peptides (B and D) in contrast with the group (A and C) in spite of the high ratio of serine and threonine, namely peptide A. The propensity for specific fragmentation of peptide D seems to be correlated to the repetitive sequence, (Gly-Ser)2. Finally, based on the m/z of the daughter-ions measured, we propose an overall mechanism as an N----O acyl shift analogous to that observed for serine- and threonine- containing peptides in solution chemistry.
采用²⁵²Cf等离子体解吸质谱法测定了四种线性合成肽（一种蛇α-神经毒素的片段）的分子量。尽管丝氨酸和苏氨酸的比例很高，如肽A，但仍报道了一组两种肽（B和D）在丝氨酸和/或苏氨酸残基水平上观察到的碎片化现象，并伴有离子/片段缔合，这与另一组肽（A和C）形成对比。肽D的特定碎片化倾向似乎与重复序列（Gly-Ser）₂相关。最后，基于所测子离子的质荷比，我们提出了一种总体机制，即类似于在溶液化学中观察到的含丝氨酸和苏氨酸肽的N→O酰基转移。
