Digestive properties of the venom of the Australian Coastal Taipan, Oxyuranus scutellatus (Peters, 1867).

The digestive properties of Australian elapid snake venoms have not been studied to any great extent. To address this, the in vitro digestive properties of Oxyuranus scutellatus (Australian Coastal Taipan) venom were investigated in a simulation of the in vivo conditions using the parameters reported for the stomach of snakes and representative prey for this species. The amount of soluble protein released was measured over time using a bicinchoninic acid (BCA) assay. Dismembered mouse hindlegs were injected intramuscularly with 0.1 ml O. scutellatus venom (concentration 10 mg/ml) and maintained in a micro-anaerobic, acidic environment (pH approximately 1.2-1.7) at 25 degrees C. The bathing liquid was sampled every 24 h for 7 days, and assayed for soluble protein. Statistical analysis revealed that O. scutellatus venom increased the rate at which proteins were released when compared to a negative control suggesting the potential importance of envenomation in the digestion of whole prey.     

Characterization of peptide components in the venom of the scorpion Liocheles australasiae (Hemiscorpiidae).

Scorpion venoms are composed of a number of neurotoxic peptides. A variety of toxins have been isolated from the venoms of scorpions of the family Buthidae, however, little interest has been paid to non-Buthidae scorpions. In this study, we examined the toxicity of the venom of Liocheles australasiae (Hemiscorpiidae) to mice and crickets, and characterized the peptide components by HPLC and mass spectrometry. Over 200 components were detected in the L. australasiae venom by LC/MS analysis, with components of molecular masses ranging from 500 to 5000 Da being particularly abundant. A number of peptides contained two to four disulfide bridges, which was estimated based on the mass difference after derivatization of Cys residues. A peptide having a monoisotopic molecular mass of 7781.6 Da and four disulfide bridges was isolated from the venom. The peptide has a primary structure similar in terms of the position of eight Cys residues to those observed in several peptides found from scorpions, ticks and insects, although biological roles of these peptides are unknown.     

蛇毒Ⅱ类磷脂酶A2功能分化的分析研究

目的：研究蛇毒Ⅱ类磷脂酶A2(PLA2)中D49 PLA2和K49 PLA2的功能分化及其功能分化决定位点的鉴定。方法：运用序列比较分析，进化树构建和DIVERGE v1．04软件计算研究D49 PLA2和K49 PLA2的功能分化情况及其分化位点。结果：序列比较分析，进化树构建和DIVERGE v1．04软件计算结果表明蛇毒Ⅱ类PLA2中D49 PLA2和K49 PLA2的确发生了功能分化，对于K49 PLA2来说，1S，7K，11Q，E12，R34，T56，N88，L92，E108，K116，K128可能为功能分化决定位点。对于D49 PLA2，L2，G33，G35，F46和Y118可能为功能分化决定位点。结论：我们首次通过序列比较分析，进化树构建和DIVERGE v1．04软件计算鉴定出蛇毒Ⅱ类PLA2中D49 PLA2和K49 PLA2可能的功能分化位点，为今后通过基因重组和定点突变方法研究蛇毒Ⅱ类PLA2结构功能关系提供了线索。     

蛇毒溶栓素对实验动物血小板功能和环腺苷酸含量的影响

本文报道蛇毒溶栓素对实验动物血小板功能和血浆环腺苷酸含量的影响.(1)对血小板数的影响:给家犬以4 u/kg量静注1小时后,循环血的血小板数由药前130.44×10~9/L±50.02×10~9/L下降至60.20×10~9/L±20.50×10~9/L(P<0.05).(2)对血小板聚集功能的影响:猕猴和家兔分别按4 u/kg、8 u/kg量静注1小时后,对ADP诱导的血小板聚集率分别山药前的62.32±22.05%和43.66±10.60%下降至1.32±0.49%和4.95±1.96%;抑制率分别为97.50±1.75%和88.34±4.31%,与药前组相比均有非常显著的差异(P<0.001).(3)对血小板cAMP含量的影响:猕猴和家兔以蛋白竞争结合法测定血小板内cAMP的含量,药后1小时的含量65.43±31.35pmole/mg,32.25±15.43pmo1e/mg蛋白质,与药前12.02±0.95pmole/mg,4.25±3.13pmole/mg蛋白质相比有明显升高(P<0.001).     

蛇毒治疗不能解释肺动脉高压的研究

本通过对不能解释的肺动脉高压患，进行右心导管测定肺动脉平均压（ＰＡＭＰ）作为主要对照指标，观察蛇毒制品（精制溶栓酶）的急性药物试验和近期药物试验。发现该药物在近期有理想的降低ＰＡＭＰ作用，症状及胸片、超声心动图异常也明显取得改善，提示其可能为治疗该病的理想药物。     

蝎蜂毒肽对大鼠纤溶系统作用初探

本研究采用大鼠肢体血管灌流和整体给药两种模型，观察蝎蜂毒（ＳＢＰ）对血管理灌流液内纤溶酶原激活物（ＰＡ）活性、血浆优球蛋白纤溶性（ＥＦＡ）和纤溶酶（ＰＬ）活性的影响。结果说明，ＳＢＰ有明显激活纤溶系统作用；其机制可能涉及血管内皮细胞释放ＰＡ活性增加，进一步促使纤溶酶原活化为ＰＬ增多的途径。     

蝰蛇毒压电免疫传感器固定方法的研究

目的：为研制蝰蛇毒压电免疫传感器，研究抗蛇毒抗体固定于石英晶体银电极表面的固定技术。方法：采用马抗蝰蛇毒血清抗体和抗蝰蛇毒鸡卵黄抗体作为生物敏感材料，对比研究了胱胺自组装-PSS反相吸附法和PEI粘附-戊二醛交联法：比较了采用两种固定方法所制的压电免疫传感器的性能。结果：鸡卵黄抗体采用PEI粘附-戊二醛交联法效果较好，其制备的IgY压电免疫传感器检测蝰蛇毒灵敏度为0．5ug／mL；而马血清抗体用胱胺自组装-PSS反相吸附法较好，其制备的IgG’免疫传感器检测蝰蛇毒灵敏度为10ug／mL。结论：以PEI粘附-戊二醛交联法固定抗蝰蛇毒鸡卵黄抗体所制备的蝰蛇毒压电免疫传感器的性能稳定，特异性好，可实现蛇毒的快速检测。     

中华眼镜蛇毒组分C抗白血病作用的实验研究

目的：研究眼镜蛇毒组分Ｃ对白血病细胞的直接作用及机制。方法：应用ＭＴＴ、ＤＮＡ电泳、流式细胞仪ＲＴ－ＰＣＲ等方法,观察眼镜蛇毒组分Ｃ对ＨＬ６０等９株白血病细胞系的毒性作用、量效关系及白血病细胞经过眼镜蛇毒组分Ｃ处理后的生物化学、Ｂｃｌ－２／Ｂａｘ表达水平变化。结果：眼镜蛇毒组分对９株人白血病细胞系均有明显的抑制作用,ＩＣ５０为０．００４６～４．４０μｇ／ｍｌ,且呈较好的量效关系（ｒ为０．６６～０．     

The purification and partial characterisation of two novel metalloproteinases from the venom of the West African carpet viper, Echis ocellatus.

Separation of previously uncharacterised Echis ocellatus venom by phenyl-Superose FPLC (Fast Liquid Protein Chromatography) yielded eight protein fractions. Three of these displayed high proteolytic activity when assayed by in vivo and in vitro assays (including enzyme linked immunosorbant assay), and were further separated using Superdex 75 and Mono-Q FPLC. This resulted in the purification of a non-haemorrhagic 24 kDa metalloproteinase (EoVMP1, pI 7.0), and a haemorrhagic 56 kDa metalloproteinase (EoVMP2, pI 5.5). Following tryptic digest, short amino acid sequences of EoVMP1 and EoVMP2 were obtained using Edman degradation. Both sequences displayed homology when aligned with existing snake venom metalloproteinases (SVMPs). The strong homology observed among previously well-characterised SVMPs suggests that principles governing the interaction of substrates and inhibitors are likely to be similar for EoVMP1, EoVMP2 and all members of the reprolysin family.     

Biophysical, histopathological and pharmacological characterization of crotamine isoforms F22 and F32.

Two major crotamine isoforms (F22 and F32) were obtained after three chromatographic steps and were assayed in mouse phrenic nerve-diaphragm preparations. F32 and F22 (0.5 microg/ml, n=4) produced a facilitatory effect, which increased isometric twitch-tension by 300 and 230%, respectively, after a 120 min incubation. At a concentration of 0.1 microg/ml, both isoforms increased the twitch-tension by about 160%. However, when the isoforms were co-incubated (final concentration, 0.5 microg/ml) for 30 min prior to testing, they did not cause the facilitation seen with > or =0.1 microg/ml of each isoform alone. Histologically, F32 and F22 at 0.5 and 1 microg/ml were quantitatively alike in inducing tissue myonecrosis. However, a mixture of the two isoforms (final concentration, 0.5 microg/ml) significantly attenuated the damage seen with either toxin alone. Mass spectrometry analysis showed that the isoforms had the same molecular mass (4.8 kDa) and that they existed as monomers with a highly stable structure. These results indicate that F22 and F32 acted on muscle cells of the mouse phrenic-nerve diaphragm preparation through similar mechanisms. Since the isoforms did not produce the expected summation in the increase in muscle twitch-tension, it is possible that they may have different affinities for the sodium channel subunits.