蜘蛛毒液由类胰岛荷尔蒙进化而来

时间：2015-06-15 06:55:41

（单词翻译:单击）

Funnel-web spider venom1 contains powerful neurotoxins that instantly paralyze prey4 (usually insects). Millions of years ago, however, this potent5 poison was just a hormone6 that helped ancestors of these spiders regulate sugar metabolism7, similar to the role of insulin in humans. Surprisingly, this hormone's weaponization--described on June 11 in the journal Structure--occurred in arachnids as well as centipedes, but in different ways. Researchers at the University of Queensland in Australia and Lewis & Clark College in Portland, Oregon, made the connection while screening for similarities between the venom proteins and other molecules8. They found that even though the toxins3 and the hormone had different genetic9 sequences, they had similar molecular10 shapes.
 
"If you take the sequence of the spider toxin2 and you do a BLAST search, the hormone is so different now that you don't pull it out," said study senior author Glenn King, a biochemist and structural11 biologist at the University of Queensland's Institute for Molecular Bioscience. "But when we did a structural search and it pulled up the hormone, that's what really surprised us--the sequence didn't tell us where the toxins evolved from, but the structure did pretty clearly."
 
Knowing a toxin's past is useful for the development of new pharmaceuticals12 and bioinsecticides. Venom molecules are extremely complex (some are made up of over 3,000 peptides), so once the structure is known, researchers such as King can more easily "evolve" a toxin by making changes to its sequence to add or remove functions. The products of such experiments have yielded blood pressure drugs, analgesics13, and bioinsecticides--all organically based and so naturally break down. 
 
King's group found that centipede venom has more subtle alterations14 of the hormone that make it more stable and therefore a better engineering template. He is collaborating15 with biological and chemical engineer Jennifer Cochran at Stanford University to conduct these in vitro evolution experiments on the spider and centipede toxins. The goal is to take away their toxicity16 and find opportunities to use them to solve agricultural or medical problems.

分享到：


点击收听单词发音收听单词发音  

1 venom qLqzr     
n.毒液，恶毒，痛恨
参考例句：
  • The snake injects the venom immediately after biting its prey.毒蛇咬住猎物之后马上注入毒液。
  • In fact,some components of the venom may benefit human health.事实上，毒液的某些成分可能有益于人类健康。
2 toxin hn5wb     
n.毒素，毒质
参考例句：
  • Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
  • Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。
3 toxins 18c3f40d432ba8dc33bad8fb82873ea8     
n.毒素( toxin的名词复数 )
参考例句：
  • The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
  • Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》
4 prey g1czH     
n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨
参考例句：
  • Stronger animals prey on weaker ones.弱肉强食。
  • The lion was hunting for its prey.狮子在寻找猎物。
5 potent C1uzk     
adj.强有力的，有权势的；有效力的
参考例句：
  • The medicine had a potent effect on your disease.这药物对你的病疗效很大。
  • We must account of his potent influence.我们必须考虑他的强有力的影响。
6 hormone uyky3     
n.荷尔蒙，激素，内分泌
参考例句：
  • Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
  • This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
7 metabolism 171zC     
n.新陈代谢
参考例句：
  • After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
  • All living matter undergoes a process of metabolism.生物都有新陈代谢。
8 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句：
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。
9 genetic PgIxp     
adj.遗传的，遗传学的
参考例句：
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
10 molecular mE9xh     
adj.分子的；克分子的
参考例句：
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
11 structural itXw5     
adj.构造的，组织的，建筑（用）的
参考例句：
  • The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
  • The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。
12 pharmaceuticals be065c8a4af3a2d925d11969faac34cf     
n.医药品；药物( pharmaceutical的名词复数 )
参考例句：
  • the development of new pharmaceuticals 新药的开发
  • The companies are pouring trillions of yen into biotechnology research,especially for pharmaceuticals and new seeds. 这些公司将大量资金投入生物工艺学研究，尤其是药品和新种子方面。 来自《简明英汉词典》
13 analgesics f0b518b9f904c9ad65ac822de28f1dac     
n.止痛剂，镇痛剂( analgesic的名词复数 )
参考例句：
  • Management of lumbar strain includes analgesics and rest during the acute phase. 在急性期，腰部劳损的处理包括用止痛剂及休息，在床垫下面放置硬板。 来自互联网
  • I've taken a lot of analgesics. But they are not so effective. 我吃了不少镇痛药。促是效果不怎么好。 来自互联网
14 alterations c8302d4e0b3c212bc802c7294057f1cb     
n.改动( alteration的名词复数 )；更改；变化；改变
参考例句：
  • Any alterations should be written in neatly to the left side. 改动部分应书写清晰，插在正文的左侧。 来自《简明英汉词典》
  • Gene mutations are alterations in the DNA code. 基因突变是指DNA 密码的改变。 来自《简明英汉词典》
15 collaborating bd93aed5558c4b146fa553d822f7c432     
合作( collaborate的现在分词 )； 勾结叛国
参考例句：
  • Joe is collaborating on the work with a friend. 乔正与一位朋友合作做那件工作。
  • He was not only learning from but also collaborating with Joseph Thomson. 他不仅是在跟约瑟福？汤姆逊学习，而且也是在和他合作。
16 toxicity InYwc     
n.毒性，毒力
参考例句：
  • The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
  • Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关，对蚯蚓的毒性是相似的。

©2005-2010英文阅读网