研究人员破解蛋白质双重职能之谜
文章来源:未知 文章作者:meng 发布时间:2009-12-14 00:12 字体: [ ]  进入论坛
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Researchers at The Scripps思科利普斯 Research Institute have solved a 10-year-old mystery of how a single protein from an ancient family of enzymes酶类,酵素 can have two completely distinct roles in the body. In addition to除……之外 providing guidance for understanding other molecules4 in the family, the research supplies a theoretical underpinning支柱,基础 for the protein's possible use for combating diseases including cancer and macular degeneration黄斑变性. The research was published in the December 13, 2009 advance, online issue of the high-impact journal Nature Structural6 and Molecular7 Biology.

The scientists, led by Scripps Research Associate Professor Xiang-Lei Yang, focused on a molecule3 called human tryptophanyl色氨酰基-tRNA转核糖核酸 synthetase合成酶 (TrpRS), finding that it contains a "functional8 switch" that enables it to perform two different functions. In one of its forms, the molecule acts to facilitate促进,帮助 protein synthesis蛋白质合成. In the second form, the same molecule works to inhibit9 the formation of new blood vessels11—an effect that, if successfully harnessed, could be medically useful.

"I'm very excited about these findings," said Yang. "This piece of work provides a very deep mechanistic understanding. It has really shown that the activity of this tRNA synthetase is of biological significance and that it's a good example of the many, many different functions that have been found with the tRNA synthetase family."

One Enzyme1, Two Functions

For some time, scientists have known that the aminoacyl tRNA synthetase family is composed of 20 ancient enzymes2 that attach the correct amino氨基 acid to a tRNA as the first step in the synthesis of proteins.

The mystery of the protein family's dual12 functionality, however, was born about a decade ago, with the publication of a 1999 paper in the journal Science by Paul Schimmel, who is Ernest and Jean Hahn Professor of Molecular Biology and Chemistry and a member of The Skaggs Institute for Chemical Biology at Scripps Research, in collaboration13 with合作 a member of his lab at that time, Keisuke Wakasugi.

In the 1999 paper, Wakasugi and Schimmel showed that a member of the human aminoacyl-tRNA synthetase family, tyrosyl-tRNA synthetase (TyrRS), did more than adding the amino acid tyrosine酪氨酸 to a protein chain during protein synthesis. In addition, a fragment of the protein could function to attract immune cells and to stimulate14 the growth of blood vessels.

The findings were met with astonishment15 and some skepticism怀疑论 in the scientific community.

Soon afterward16, however, the Schimmel lab showed that another member of the family, TrpRS, also had a dual function. In addition to its role adding the amino acid tryptophan to a protein chain during protein synthesis, a fragment of TrpRS could inhibit new blood vessel10 formation.

Since that time, there has been considerable therapeutic17 interest in TyrRS, TrpRS, and other members of the aminoacyl-tRNA synthetase family. As a pro-angiogenic factor, the TyrRS fragment could be useful in diseases where growth of blood vessels is desirable, such as in some forms of heart disease or peripheral外围的,次要的 artery19 disease. Likewise, the TrpRS fragment's anti-angiogenic effects could help patients reduce undesirable20 blood vessel growth in diseases such as cancer and a great many eye diseases that lead to catastrophic vision loss.

In fact, fragments of TrpRS were used as part of a study led by Scripps Research Professor Martin Friedlander that successfully halted the progression in animal models of highly vascular血管的 brain tumor22 and neovascular eye disease (PNAS 2007 104:967-972).

Despite the interest in tRNA synthetases, however, no one has been able to figure out exactly how they perform their different roles—until now.



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1 enzyme cPozF     
n.酵素,酶
参考例句:
  • Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度,酶分子将会展开。
  • An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。
2 enzymes 7881ad8ce9c83424f7874e70266ed2d8     
n. 酶,酵素
参考例句:
  • It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
  • Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。
3 molecule Y6Tzn     
n.分子,克分子
参考例句:
  • A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈?f婘??妈?成的。
  • This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
4 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。
5 underpinning 7431aa77983d1e766a4ef27b6d3f1735     
n.基础材料;基础结构;(学说、理论等的)基础;(人的)腿v.用砖石结构等从下面支撑(墙等)( underpin的现在分词 );加固(墙等)的基础;为(论据、主张等)打下基础;加强
参考例句:
  • Underpinning this success has been an exemplary record of innovation. 具有典范性的创新确保了这次成功。 来自辞典例句
  • But underpinning Mr Armstrong's technology changes is a human touch. 但阿姆斯特朗技术变革的支柱是人情味。 来自互联网
6 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。
7 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。
8 functional 5hMxa     
adj.为实用而设计的,具备功能的,起作用的
参考例句:
  • The telephone was out of order,but is functional now.电话刚才坏了,但现在可以用了。
  • The furniture is not fancy,just functional.这些家具不是摆着好看的,只是为了实用。
9 inhibit C7jxT     
vt.阻止,妨碍,抑制
参考例句:
  • Don't let ego and greed inhibit clear thinking and hard work.不要让自我和贪婪妨碍清晰的思维和刻苦的工作。
  • They passed a law to inhibit people from parking in the street.他们通过一项法令以阻止人们在街上停车。
10 vessel 4L1zi     
n.船舶;容器,器皿;管,导管,血管
参考例句:
  • The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
  • You should put the water into a vessel.你应该把水装入容器中。
11 vessels fc9307c2593b522954eadb3ee6c57480     
n.血管( vessel的名词复数 );船;容器;(具有特殊品质或接受特殊品质的)人
参考例句:
  • The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
  • All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》
12 dual QrAxe     
adj.双的;二重的,二元的
参考例句:
  • The people's Republic of China does not recognize dual nationality for any Chinese national.中华人民共和国不承认中国公民具有双重国籍。
  • He has dual role as composer and conductor.他兼作曲家及指挥的双重身分。
13 collaboration bW7yD     
n.合作,协作;勾结
参考例句:
  • The two companies are working in close collaboration each other.这两家公司密切合作。
  • He was shot for collaboration with the enemy.他因通敌而被枪毙了。
14 stimulate wuSwL     
vt.刺激,使兴奋;激励,使…振奋
参考例句:
  • Your encouragement will stimulate me to further efforts.你的鼓励会激发我进一步努力。
  • Success will stimulate the people for fresh efforts.成功能鼓舞人们去作新的努力。
15 astonishment VvjzR     
n.惊奇,惊异
参考例句:
  • They heard him give a loud shout of astonishment.他们听见他惊奇地大叫一声。
  • I was filled with astonishment at her strange action.我对她的奇怪举动不胜惊异。
16 afterward fK6y3     
adv.后来;以后
参考例句:
  • Let's go to the theatre first and eat afterward. 让我们先去看戏,然后吃饭。
  • Afterward,the boy became a very famous artist.后来,这男孩成为一个很有名的艺术家。
17 therapeutic sI8zL     
adj.治疗的,起治疗作用的;对身心健康有益的
参考例句:
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候,音乐有治疗效力。
18 peripheral t3Oz5     
adj.周边的,外围的
参考例句:
  • We dealt with the peripheral aspects of a cost reduction program.我们谈到了降低成本计划的一些外围问题。
  • The hotel provides the clerk the service and the peripheral traveling consultation.旅舍提供票务服务和周边旅游咨询。
19 artery 5ekyE     
n.干线,要道;动脉
参考例句:
  • We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
  • The aorta is the largest artery in the body.主动脉是人体中的最大动脉。
20 undesirable zp0yb     
adj.不受欢迎的,不良的,不合意的,讨厌的;n.不受欢迎的人,不良分子
参考例句:
  • They are the undesirable elements among the employees.他们是雇员中的不良分子。
  • Certain chemicals can induce undesirable changes in the nervous system.有些化学物质能在神经系统中引起不良变化。
21 vascular cidw6     
adj.血管的,脉管的
参考例句:
  • The mechanism of this anomalous vascular response is unknown.此种不规则的血管反应的机制尚不清楚。
  • The vascular changes interfere with diffusion of nutrients from plasma into adjacent perivascular tissue and cells.这些血管变化干扰了营养物质从血浆中向血管周围邻接的组织和细胞扩散。
22 tumor fKxzm     
n.(肿)瘤,肿块(英)tumour
参考例句:
  • He was died of a malignant tumor.他死于恶性肿瘤。
  • The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。
TAG标签: protein enzymes molecule
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