T-2毒素对狂犬病病毒体外复制的抑制作用研究

探索T-2毒素对狂犬病病毒CVS-11的体外抑制作用。通过CCK-8法确定T-2毒素在BHK-21细胞中的工作浓度,根据T-2毒素、狂犬病病毒CVS-11与BHK-21细胞的相互作用方式建立T-2毒素体外抗狂犬病病毒的作用模型。采用直接免疫荧光、细胞荧光转化灶、实时荧光定量PCR等方法明确T-2毒素对狂犬病病毒CVS-11的体外抑制作用。CCK-8实验结果显示,T-2毒素与BHK-21细胞相互作用3h和24h的最大工作浓度分别为40ng/mL和10ng/mL。体外抗病毒实验的作用模型结果显示,增加T-2毒素浓度,狂犬病病毒CVS-11的病毒滴度和N基因mRNA的表达量逐渐下降,5ng/mL的T-2毒素对狂犬病病毒CVS-11抑制率可达90%以上,40ng/mL的T-2毒素对狂犬病病毒CVS-11具有灭活作用,灭活抑制率达80%以上。T-2毒素对狂犬病病毒具有体外抑制作用,且这种抑制作用具有剂量依赖性。     

产自东亚钳蝎的钠通道调节剂的抗癫痫/促癫痫作用（英文）

东亚钳蝎(Buthus martensii Karsch, BmK)是治疗癫痫的经典中药之一,已有上千年的历史。从BmK毒液中分离纯化的神经毒素被认为是作用于膜离子通道的主要活性成分。电压门控钠通道(voltage-gated sodium channels, VGSCs)在癫痫发生中起着重要的作用,使其成为重要的癫痫药物靶点。BmK的长链毒素由60～70个氨基酸残基组成,能特异性识别VGSCs,其中用于建立癫痫模型的α-样神经毒素与VGSC受体位点3结合,可诱发鼠类癫痫。而β或β-样神经毒素则与VGSC受体位点4结合,对癫痫模型有显著的抗惊厥作用。本综述旨在阐明BmK多肽作用于VGSCs的抗惊厥或惊厥作用,同时也为抗癫痫药物设计提供潜在的框架。     

The cDNA and genomic DNA organization of a novel toxin SHT-I from spider Ornithoctonus huwena

Spider venoms are complex mixtures of neurotoxicpeptides, proteins and low molecular mass organicmolecules. Their neurotoxic activity is due to the interac-tion of the venom components with cellular receptors, inparticular ion channels. Spider venoms have…     

蓝色染料配基亲和纯化眼镜蛇心脏毒素的研究

探索了蓝色染料（Cibacron Blue F3G-A）亲和分离中华眼镜蛇心脏毒素的可能性。采用环氧基活化法制备蓝色染料亲和介质,中性条件下提取眼镜蛇粗毒中的心脏毒素。Tricine系统SDS-PAGE多肽电泳和Lowry法蛋白定量分析纯化效果,发现蓝色染料琼脂糖一步纯化中华眼镜蛇心脏毒素的纯度达到84%,结合量为6.9mg/ml介质。这是首次利用小分子亲和配基纯化心脏毒素。与生物大分子配基相比,活性染料分子具有价格便宜,易于合成,性质稳定,不易降解和适合大规模生产等优点。     

Characterization of a novel toxin-antitoxin module, VapBC, encoded by Leptospira interrogans chromosome

Comparative genomic analysis of the coding sequences (CDSs) of Leptospira interrogans revealed a pair of closely linked genes homologous to the vapBC loci of many other bacteria with respect to both deduced amino acid sequencesand operon organizations. Expression of single vapC gene in Escherichia coli resulted in inhibition of bacterial growth,whereas co-expression of vapBC restored the growth effectively. This phenotype is typical for three other character-ized toxin-antitoxin systems of bacteria, i.e., mazEF[1], reIBE[2] and chplK[3]. The VapC proteins of bacteria and a thermophilic archeae, Solfolobus tokodaii, form a structurally distinguished group of toxin different from the other known toxins of bacteria. Phylogenetic analysis of both toxins and antitoxins of all categories indicated that althought oxins were evolved from divergent sources and may or may not follow their speciation paths (as indicated by their 16s RNA seouences）, co-evolution with their antitoxins was obvious.     

Human μ—opioid receptor overexpressed in Sf9 insect cells functionally coupled to endogenous Gi／0 proteins

Human mu-opioid receptor (HmuOR) with a tag of six consecutive histidines at its carboxyl terminus had been expressed in recombinant baculovirus infected Sf9 insect cells. The maximal binding capacity for the [3H] diprenorphine and [3H]ohmefentanyl (Ohm) were 9.1 +/- 0.7 and 6.52 +/- 0.23 nmol/g protein, respectively. The [3H] diprenorphine or [3H] Ohm binding to the receptor expressed in Sf9 cells was strongly inhibited by mu-selective agonists [D-Ala2, N-methyl-Phe4, glyol5]enkephalin (DAGO), Ohm, and morphine, but neither by delta nor by kappa selective agonist. Na+ (100 mM) and GTP (50 microM) could reduce HmuOR agonists etorphine and Ohm affinity binding to the overexpressed HmuOR. mu-selective agonists DAGO and Ohm effectively stimulated [35S]GTP-gammaS binding (EC50 = 2.7 nM and 6.9 nM) and inhibited forskolin- stimulated cAMP accumulation (IC50 = 0.9 nM and 0.3 nM). The agonist-dependent effects could be blocked by opioid antagonist naloxone or by pretreatment of cells with pertussis toxin (PTX). These results demonstrated that HmuOR overexpressed in Sf9 insect cells functionally coupled to endogenous G(i/o) proteins.     

球孢白僵菌毒素的分离、毒力检测及结构鉴定

用吸附法从球孢白僵菌(Beauveria bassiana)1003-V的代谢产物中分离出导致昆虫患病的毒素粗提物(以下简称毒素),并对其进行了毒力检测.结果表明,该毒素对白纹伊蚊(Aedes albopictus)幼虫有明显毒性;对棉铃虫(Heliothis zea)幼虫口服毒性较弱,血腔注射毒性较强;仅对革兰氏阳性细菌有抑菌作用.对草地夜蛾(Spodoptera frugiperda)Sf-21细胞株的毒力测定结果表明,毒力回归方程为y=2.03+2.39x,半致死浓度是0.01751%,其95%可信极限为0.01517%~0.0202%.高压液相色谱和红外光谱分析表明,该毒素含有三种在结构和性质上非常相近的物质.     

苏云金杆菌毒素

苏云金杆菌产生的对昆虫有致病作用的毒素有７种,即α－外毒素、β－外毒素、γ－外毒素、δ－内毒素、不稳定外毒素、水溶性毒素、鼠因子外毒素。苏云金杆菌主要是经口感染昆虫,它杀死昆虫可由菌体本身的活动而引起,但是使害虫死亡的更主要的原因是菌体产生的毒素。毒...     

棉铃虫对Bt生物农药早期抗性及与转Bt基因棉抗虫性的关系

用饲料感染法建立了棉铃虫Helicoverpa rmigera(Hubmer)敏感品系(SUS1)对Bt生物农药的敏感毒力基线和区分剂量,1995年测定了五省六县棉铃虫初孵幼虫对Bt生物农药的敏感性,结果表明：山东阳谷、河北邯郸、河南新乡、安徽萧县及江苏丰县棉铃虫已产生早期抗性,抗性个体百分率为5%～10%,与敏感品系相比,LC₅₀值稍有增加,但斜率b值明显变小;而江苏东台棉铃虫仍属敏感。这是国内外首次诊测到棉铃虫对Bt生物农药抗性。用棉叶喂饲法测定比较了转Bt基因棉花品系对不同种群棉铃虫的抗虫性效果,结果表明：用早期抗性的阳谷和新乡棉铃虫初孵幼虫接虫5d后平均死亡率较敏感品系下降16%～29%,说明棉铃虫对Bt农药与转Bt生物基因棉花品系间存在交互抗性。还讨论了Bt农药的抗性治理对策。     

蛇毒心脏毒素对动物细胞的遗传损伤和生殖毒性研究

目的 应用眼镜蛇毒心脏毒素（ＣＴＸ）作用于小鼠的骨髓细胞和生殖细胞,以探讨ＣＴＸ对动物体的生殖毒性和遗传毒性。方法 对小鼠腹腔注射不同剂量ＣＴＸ,通过生殖毒性实验和致突变实验,分析孕鼠的胚胎存活率,骨髓细胞和精母细胞的染色体畸变率。结果：ＣＴＸ能影响胎鼠的生长发育,使孕鼠的增重和活胎率均明显地降低（Ｐ〈０．００１）,染色体畸变实验显示ＣＴＸ０．４ｍｇ／ｋｇ剂量上精母细胞多倍体和非整倍体细胞数目增高