本文对 110 m Ag在海洋环境中的化学形态和在底泥上的吸附行为及在海洋生物中的浓集状况进行了研究。结果表明 ,110 m Ag在海水中以110 m Ag+ ∶ 110 m Ag Cl2 -≈ 10 -5存在 ,且当 [Ag+ ][Cl-]达到 Ag Cl的溶度积 (1.56× 10 -10 ...本文对 110 m Ag在海洋环境中的化学形态和在底泥上的吸附行为及在海洋生物中的浓集状况进行了研究。结果表明 ,110 m Ag在海水中以110 m Ag+ ∶ 110 m Ag Cl2 -≈ 10 -5存在 ,且当 [Ag+ ][Cl-]达到 Ag Cl的溶度积 (1.56× 10 -10 )时便生成 Ag Cl沉淀。海水中的 110 m Ag在底泥上的吸附系数随温度的升高或固液体积比增大而减小 ,尤其是受水质影响很大 ,海水中 110 m Ag在底泥中的吸附系数 (10 2 )比淡水中低两个量级。海洋生物对海水中的 110 m Ag有较强的浓集作用 ,依生物种类不同其生物累积因子的量级为 10 2～ 10 4。展开更多
The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was ...The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.展开更多
文摘本文对 110 m Ag在海洋环境中的化学形态和在底泥上的吸附行为及在海洋生物中的浓集状况进行了研究。结果表明 ,110 m Ag在海水中以110 m Ag+ ∶ 110 m Ag Cl2 -≈ 10 -5存在 ,且当 [Ag+ ][Cl-]达到 Ag Cl的溶度积 (1.56× 10 -10 )时便生成 Ag Cl沉淀。海水中的 110 m Ag在底泥上的吸附系数随温度的升高或固液体积比增大而减小 ,尤其是受水质影响很大 ,海水中 110 m Ag在底泥中的吸附系数 (10 2 )比淡水中低两个量级。海洋生物对海水中的 110 m Ag有较强的浓集作用 ,依生物种类不同其生物累积因子的量级为 10 2～ 10 4。
基金This work was supported by a grant from 863High Technology Program,Chinese Ministry of Sci-ence and Technology
文摘The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.
