Gopalakrishnakone P, Yuen R, Tan C H
Department of Anatomy, Faculty of Medicine, National University of Singapore.
Toxicon. 1995 Jan;33(1):63-76. doi: 10.1016/0041-0101(94)00133-s.
A major lethal factor, daboiatoxin (DbTx), showing strong PLA2 activity (specific activity 91.7 nmoles/min/mg), was purified to homogeneity from the venom of Burmese Russell's viper (Daboia r. siamensis) by a combination of gel filtration on Sephadex G-75 and ion-exchange chromatography on CM-Sephadex C-25, followed by purification on high-performance gel filtration Shim-pack Diol-150 column. DbTx is a single-chain PLA2 toxin with approximate mol. wt 15,000 as determined by HPLC gel filtration and SDS-PAGE. It constitutes 12% of total venom protein and is the main lethal component of Burmese Russell's viper venom with an LD50 i.p. (0.05 mg/kg) 12-fold greater than that of the whole venom (LD50 i.p. 0.6 mg/kg). DbTx produces neurotoxic symptoms in mice and exhibits potent oedema-inducing activity (minimum oedema dose 0.05 microgram), indirect haemolytic activity and a strong myonecrotic activity, but no haemorrhagic activity. DbTx is cytotoxic to HeLa cells causing cytolysis of the cells 24 hr post-exposure to toxin (50 micrograms/ml). The first 20 N-terminal amino acid sequence (NFFQF AEMIV KMTGK EAVHS) shows a significant resemblance to those of the PLA2s from the venoms of Bulgarian viper (V. a. ammodytes) and Taiwan Russell's viper (V. r. formosensis).
一种主要的致死因子——达波伊毒素（DbTx），具有很强的磷脂酶A2（PLA2）活性（比活性为91.7纳摩尔/分钟/毫克），通过在Sephadex G - 75上进行凝胶过滤和在CM - Sephadex C - 25上进行离子交换色谱相结合的方法，从缅甸罗素蝰蛇（Daboia r. siamensis）的毒液中纯化至同质，随后在高效凝胶过滤Shim - pack Diol - 150柱上进一步纯化。通过高效液相色谱凝胶过滤和十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS - PAGE）测定，DbTx是一种单链PLA2毒素，分子量约为15000。它占毒液总蛋白的12%，是缅甸罗素蝰蛇毒液的主要致死成分，其腹腔注射半数致死量（LD50）（0.05毫克/千克）比全毒液的LD50（腹腔注射0.6毫克/千克）大12倍。DbTx在小鼠中产生神经毒性症状，并表现出强大的致水肿活性（最小致水肿剂量0.05微克）、间接溶血活性和强烈的肌坏死活性，但无出血活性。DbTx对HeLa细胞具有细胞毒性，在暴露于毒素（50微克/毫升）24小时后可导致细胞溶解。其前20个N端氨基酸序列（NFFQF AEMIV KMTGK EAVHS）与保加利亚蝰蛇（V. a. ammodytes）和台湾罗素蝰蛇（V. r. formosensis）毒液中的PLA2s有显著相似性。
