Isolation of a Na_v channel blocking polypeptide from Cyanea capillata medusae - A neurotoxin contained in fishing tentacle isorhizas

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• 作者：Stephan Lassen^a ; ^b ; ^{stephan.lassen@hzg.de} ; Annika Wiebring^a ; ^c ; Heike Helmholz^a ; Christiane Ruhnau^a ; Andreas Prange^a
• 关键词：Jellyfish ; Cyanea ; Nematocysts ; Neurotoxin ; Mass spectrometry
• 刊名：Toxicon
• 出版年：2012
• 出版时间：May, 2012
• 年：2012
• 卷：59
• 期：6
• 页码：610-616
• 全文大小：540 K

文摘

Jellyfish are efficient predators which prey on crabs, fish larvae, and small fish. Their venoms consist of various toxins including neurotoxins that paralyse prey organisms immediately. One possible mode of action of neurotoxins is the blockage of voltage-gated sodium (Na_v) channels. A novel polypeptide with Na_v channel blocking activity was isolated from the northern Scyphozoa Cyanea capillata (L., 1758). For that purpose, a bioactivity-guided multidimensional liquid chromatographic purification method has been developed. A neurotoxic activity of resulting chromatographic fractions was demonstrated by a bioassay, which based on the mouse neuroblastoma cell line Neuro2A. The purification process yielded one fraction containing a single polypeptide with proven activity. The molecular weight of 8.22 kDa was determined by matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF MS). Utilising Laser Microdissection and Pressure Catapulting (LMPC) for the separation of different nematocyst types in combination with direct MALDI-ToF MS analysis of the intact capsules, the neurotoxin was found to be present in all types of fishing tentacle isorhizas (A-isorhizas, a-isorhizas, O-isorhizas) of C. capillata medusae.