Jakubowski Jennifer A, Kelley Wayne P, Sweedler Jonathan V
Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue 63-5, Urbana, IL 61801, USA.
Toxicon. 2006 May;47(6):688-99. doi: 10.1016/j.toxicon.2006.01.021. Epub 2006 Mar 30.
Mass spectrometry has emerged as an important technique for conotoxin analysis due to its capacity for selective, sensitive, information-rich analyses. Using liquid chromatography/mass spectrometry, Conus venom can be fractionated and the peptides surveyed for specific post-translational modifications, indicating those toxin components likely to have an important biological function. With Conus striatus and Conus victoriae venom as models, bromination, carboxylation and glycosylation modifications are identified through characteristics such as isotopic distribution and labile losses observed during mass spectrometric analysis. This modification screening approach enables the identification of a C. victoriae bromo-carboxy-conotoxin, designated vc5c, as a candidate for detailed mass spectrometric analysis. Using a cDNA sequence coupled with liquid chromatography/mass spectrometry and nanoelectrospray ionization-ion trap-mass spectrometry, the sequence of vc5c is determined to be ICCYPNXWCCD, where W is 6-bromotryptophan, X is gamma-carboxy glutamate and C is disulfide-linked cysteine. This represents the ninth T-superfamily (-CC-CC- scaffold) toxin that has been isolated from venom and characterized.
由于质谱分析法能够进行选择性、灵敏且信息丰富的分析，它已成为芋螺毒素分析的一项重要技术。利用液相色谱/质谱联用技术，芋螺毒液能够被分离，并且可以对肽段进行特定翻译后修饰的检测，从而找出那些可能具有重要生物学功能的毒素成分。以条纹芋螺和维多利亚芋螺毒液为模型，通过质谱分析过程中观察到的同位素分布和不稳定损失等特征，鉴定出了溴化、羧化和糖基化修饰。这种修饰筛选方法能够鉴定出一种维多利亚芋螺溴代羧基芋螺毒素，命名为vc5c，作为进行详细质谱分析的候选对象。结合cDNA序列、液相色谱/质谱联用技术以及纳米电喷雾电离-离子阱-质谱技术，确定vc5c的序列为ICCYPNXWCCD，其中W为6-溴色氨酸，X为γ-羧基谷氨酸，C为二硫键连接的半胱氨酸。这是从毒液中分离并鉴定出的第九种T-超家族（-CC-CC-支架）毒素。
