Identification of microcystin toxins from a strain of Microcystis aeruginosa by liquid chromatography introduction into a hybrid linear ion trap-fourier transform ion cyclotron resonance mass spectrometer
Identification of microcystin toxins from a strain of Microcystis aeruginosa by liquid chromatography introduction into a hybrid linear ion trap-fourier transform ion cyclotron resonance mass spectrometer
复制标题
DOI：
10.1021/ac051556d
复制
发表时间：
2006-01-15
影响因子：
7.4
通讯作者：
Budde, WL
中科院分区：
文献类型：
--
作者：
Diehnelt, CW;Dugan, NR;Budde, WL
对一株以前未被研究过的铜绿微囊藻产生的环七肽微囊藻毒素进行了高效液相色谱分离，并对其[M+H](+)离子和[M+H](+)离子碰撞活化解离产生的碎片离子进行了高精度的m/z测定。蓝藻B2666菌株在标准生长介质中培养，毒素从细胞中释放，从水相中提取，并使用标准程序进行浓缩。用反相微孔液相色谱分离微囊藻毒素，并将其直接引入电喷雾电离的线性离子陷阱-傅里叶变换离子回旋共振质谱仪。已知的微囊藻毒素(MC)MC-LR、MG-LA、[Meser(7)]MC-LR、MC-LL、MC-LF和MC-L(Aba)以及两个以前未见报道的结构变体[Asp(3)]MC-LA和[Asp(3)]MC-LL被鉴定出来。除了[M+H](+)离子外，还对每个已鉴定的微囊藻毒素进行了12-18个产物离子的精确m/z测量。测量和计算的精确m/z之间的平均差异不到百万分之二，这通常允许对观察到的离子进行独特的成分分配。提出了一种机制，解释了一个重要的碰撞激活解离过程，该过程从不含精氨酸的微囊藻毒素中获得了有价值的序列离子。这项工作中使用的分析技术能够在没有标准时支持对已知微囊藻毒素和大多数结构变体的相当快速和非常可靠的鉴定，而不依赖于来自其他分析技术的额外信息。
The cyclic heptapeptide microcystin toxins produced by a strain of Microcystis aeruginosa that has not been investigated previously were separated by liquid chromatography and identified by high-accuracy m/z measurements of their [M + H](+) ions and the fragment ions produced by collision-activated dissociation of the [M + H](+) ions. The cyanobacteria B2666 strain was cultured in a standard growth medium, and the toxins were released from the cells, extracted from the aqueous phase, and concentrated using standard procedures. The microcystins were separated by reversed-phase microbore liquid chromatography and introduced directly into a hybrid linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer with electrospray ionization. The known microcystins (MC) MC-LR, MG-LA, [MeSer(7)]MC-LR, MC-LL, MC-LF, and MC-L(Aba) were identified along with the two previously unreported structural variants [Asp(3)]MC-LA and [Asp(3)]MC-LL. In addition to the [M + H](+) ions, accurate m/z measurements were made of 12-18 product ions for each identified microcystin. The mean difference between measured and calculated exact m/z was less than 2 parts per million, which often allowed assignment of unique compositions to the observed ions. A mechanism is presented that accounts for an important collision-activated dissociation process that gives valuable sequence ions from microcystins that do not contain arginine. The analytical technique used in this work is capable of supporting fairly rapid and very reliable identifications of known microcystins when standards are not available and of most structural variants independent of additional information from other analytical techniques.