Stonustoxin is a novel lethal factor from stonefish (Synanceja horrida) venom - cDNA cloning and characterization
Stonustoxin is a novel lethal factor from stonefish (Synanceja horrida) venom - cDNA cloning and characterization
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DOI：
10.1074/jbc.271.41.25575
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发表时间：
1996-10-11
影响因子：
4.8
通讯作者：
Yuen, R
中科院分区：
文献类型：
--
作者：
Ghadessy, FJ;Chen, DS;Yuen, R
Stonustoxin（SNTX）是从石鱼（Synanceja horrida）毒液中分离的一种多功能致死蛋白，它由α和β两个亚基组成，分子量分别为71和79 bDa。SNTX在体外和体内均能引起一系列生物学反应，尤其是通过一氧化氮途径介导的强降压作用。作为结构功能研究的前奏，我们从毒腺cDNA文库中分离并测序了编码SNTX α-和β-亚基的cDNA克隆。然而，蛋白质序列比对确实显示亚基彼此具有50%的同源性，并暗示它们可能来自共同的祖先。这种新型毒素的亚基缺乏通常在通过内质网-高尔基体途径分泌的蛋白质中发现的典型N-末端信号序列，表明其可能通过非经典途径分泌，这还不清楚，SNTX亚基已在大肠杆菌中表达为可切割的融合蛋白，其与针对天然毒素产生的抗体交叉反应。据我们所知，这是第一个报道的鱼源蛋白毒素的完整序列。
Stonustoxin (SNTX) is a multifunctional lethal protein isolated from venom elaborated by the stonefish, Synanceja horrida, It comprises two subunits, termed alpha and beta, which have respective molecular masses of 71 and 79 bDa, SNTX elicits an array of biological responses both in vitro and in vivo, particularly a potent hypotension that appears to be mediated by the nitric oxide pathway. As a prelude to structure function studies, we have isolated and sequenced cDNA clones encoding the alpha- and beta-subunits of SNTX from a venom gland cDNA library, The deduced amino acid sequence of neither subunit shows significant homology with any known protein. Protein sequence alignment does, however, show the subunits to be 50% homologous to each other and implies that they may have arisen from a common ancestor, The subunits of this novel toxin lack typical N-terminal signal sequences commonly found in proteins that are secreted via the endoplasmic reticulum-Golgi apparatus pathway, indicating the possibility of its being secreted by a non-classical pathway, which is not clearly understood, The SNTX subunits have been expressed in Escherichia coli as cleavable fusion proteins that cross-react with antibodies raised against the native toxin, To the best of our knowledge, this is the first complete sequence of a fish-derived protein toxin to be reported.