Vijayasarathy M, Balaram P
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India.
Toxicon. 2018 Mar 15;144:68-74. doi: 10.1016/j.toxicon.2018.02.005. Epub 2018 Feb 13.
Four 30 residue conotoxin have been identified from the venom of C. amadis. MS/MS analysis of crude venom subjected to global reduction/alkylation yielded fragmentation patterns, which permitted searching and matching with a database of putative mature toxin sequences obtained from transcriptomic analysis. Of the four sequences identified, Am3408(Am6.1b), Am3452(Am6.1c), Am3136(Am6.2a) and Am3214(Am6.2b), three contain bromotryptophan residues, while an additional post translational modification, gamma carboxylation of glutamic acid, is present in Am3408(Am6.1b)/3452(Am6.1c). The conotoxins belong to the O1/O2 gene superfamily and possess cysteine framework VI/VII. While, the cysteine patterns show a similarity to omega conotoxins, the three C. amadis peptides are highly negatively charged and possess a significant content of hydrophobic residues.
已从阿马迪氏芋螺毒液中鉴定出四种含30个氨基酸残基的芋螺毒素。对经过整体还原/烷基化处理的粗毒液进行串联质谱分析，得到了碎片图谱，可用于与通过转录组分析获得的假定成熟毒素序列数据库进行比对。在鉴定出的四个序列Am3408（Am6.1b）、Am3452（Am6.1c）、Am3136（Am6.2a）和Am3214（Am6.2b）中，有三个含有溴代色氨酸残基，而在Am3408（Am6.1b）/3452（Am6.1c）中还存在另一种翻译后修饰，即谷氨酸的γ羧化。这些芋螺毒素属于O1/O2基因超家族，具有半胱氨酸框架VI/VII。虽然半胱氨酸模式与ω芋螺毒素相似，但这三种阿马迪氏芋螺肽带高度负电荷，且含有大量疏水残基。
