The turripeptide ubi3a was isolated from the venom of the marine gastropod Unedogemmula bisaya, family Turridae, by bioassay-guided purification; both native and synthetic ubi3a elicited prolonged tremors when injected intracranially into mice. The sequence of the peptide, DCCOCOAGAVRCRFACC-NH₂ (O = 4-hydroxyproline) follows the framework III pattern for cysteines (CC–C–C–CC) in the M-superfamily of conopeptides. The three-dimensional structure determined by NMR spectroscopy indicated a disulfide connectivity that is not found in conopeptides with the cysteine framework III: C₁–C_4, C₂–C₆, C₃–C₅. The peptide inhibited the activity of the α9α10 nicotinic acetylcholine receptor with relatively low affinity (IC₅₀, 10.2 μM). Initial Constellation Pharmacology data revealed an excitatory activity of ubi3a on a specific subset of mouse dorsal root ganglion neurons.

中文翻译：

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乌木双叶毒液中turripeptide的结构和生物活性。

turripeptide ubi3a是通过生物测定指导纯化从海洋腹足纲乌节菌Unedogemmula bisaya（Turridae）的毒液中分离得到的。颅内注射到小鼠体内时，天然的和合成的ubi3a都会引起长时间的震颤。肽的序列DCCOCOAGAVRCRFACC-NH ₂（O = 4-羟基脯氨酸）遵循C肽超家族中半胱氨酸（CC–C–C–CC）的构架III模式。通过NMR光谱确定的三维结构表明，在具有半胱氨酸骨架III的肽类中未发现二硫键连接性：C ₁ –C _4， C ₂ –C ₆，C ₃ –C ₅。所述肽抑制α9α10烟碱乙酰胆碱受体的活性具有相对低的亲和力（IC ₅₀，μM10.2）。最初的星座药理数据显示ubi3a对小鼠背根神经节神经元的特定子集具有兴奋性。