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敬钊毒素-I(JZTX-I)是一种能够抑制心肌钠通道失活的新型蜘蛛神经毒素,该文结合高效液相色谱与色氨酸荧光测定技术研究了JZTX-I的磷脂膜结合活性。脂质体共沉淀实验表明,JZTX-I具有不依赖于带负电荷磷脂组成的生物膜结合活性。当加入由酸性或中性磷脂构成的脂质体后,JZTX-I能够分别产生6.4和4.7nm的蓝移以及7.4和8.0nm的红移激发漂移,显示JZTX-I能够插入磷脂膜,同时该分子疏水表面的色氨酸残基处于一个运动受限的界面区域。荧光淬灭实验进一步证实,与脂质体结合能够减少该毒素分子表面色氨酸残基的溶剂暴露。该研究结果为阐明JZTX-I的离子通道门控调节机制提供了新的信息。
JZTX-I is a novel spider neurotoxin that inhibits the inactivation of cardiac sodium channels. In this paper, the phospholipid membrane-bound activity of JZTX-I was studied by high performance liquid chromatography and tryptophan fluorescence assay . Liposome coprecipitation experiments showed that JZTX-I has biofilm-binding activity independent of the composition of the negatively charged phospholipid. JZTX-I was able to generate a blue shift of 6.4 and 4.7 nm and a red shift of 7.4 and 8.0 nm, respectively, upon addition of liposomes composed of acidic or neutral phospholipids, indicating that JZTX-I can insert phospholipid membranes, while The tryptophan residues on the hydrophobic surface of the molecule are in a movement-limited interface area. Fluorescence quenching experiments further confirm that binding to liposomes can reduce the solvent exposure of tryptophan residues on the surface of the toxin molecule. This study provides new information for elucidating the mechanism of ion channel gating in JZTX-I.