Steinborner S T, Bowie J H
Department of Chemistry, University of Adelaide, South Australia, Australia.
Rapid Commun Mass Spectrom. 1996;10(10):1243-7. doi: 10.1002/(SICI)1097-0231(19960731)10:10<1243::AID-RCM639>3.0.CO;2-I.
The collision-induced tandem mass spectral data for MH+ and [M-H]- ions from six bio-active peptides from Litoria rubella are compared. Backbone cleavages of [M-H]- ions provide sequencing information for five of the peptides [e.g. Phe Pro Trp Leu (NH2) and pGlu Phe Pro Trp Leu (NH2)] and in these cases, the negative-ion spectra are as informative as the positive-ion spectra. Side-chain cleavages are also noted in these spectra. For example, (i) when Trp is present, the loss of C9H7N (129 u) competes with the backbone cleavages, and (ii) the [M-H]- ion of Ile Glu Phe Phe Thr (NH2) undergoes facile side-chain fragmentation [loss of H2O (from Glu) and MeCHO (from Thr)], but does not form any conventional backbone-cleavage ions.
比较了来自红背雨蛙的六种生物活性肽的MH⁺和[M - H]⁻离子的碰撞诱导串联质谱数据。[M - H]⁻离子的主链裂解为其中五种肽提供了测序信息[例如苯丙氨酸 - 脯氨酸 - 色氨酸 - 亮氨酸（NH₂）和焦谷氨酸 - 苯丙氨酸 - 脯氨酸 - 色氨酸 - 亮氨酸（NH₂）]，在这些情况下，负离子谱与正离子谱一样具有信息价值。在这些谱中也注意到了侧链裂解。例如，（i）当存在色氨酸时，C₉H₇N（129 u）的丢失与主链裂解相互竞争，并且（ii）异亮氨酸 - 谷氨酸 - 苯丙氨酸 - 苯丙氨酸 - 苏氨酸（NH₂）的[M - H]⁻离子发生容易的侧链碎片化[从谷氨酸失去H₂O和从苏氨酸失去MeCHO]，但不形成任何常规的主链裂解离子。
