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强劲的分子发动机---RNA奈米马达（nano-motor）
一般来说，具有遗传讯息的脱氧核糖核酸DNA可以转译成核糖核酸RNA，但是RNA分子结构比DNA分子结构具有多样化的特性，也就是RNA可以形成多样的结构（诸如：单体monomer、双合体dimer、三合体trimer、六合体hexamer等等）。
普渡大学分子病毒学教授Peixuan Guo的研究团队，早于1987年在phi29病毒里发现一种特殊的RNA结构，它称为pRNA(packaging RNA)，其pRNA单体(monomer)之间可以互相联结组合成六合体（hexamer）环状结构，而这种六合体环状结构又称做奈米马达（nano-motor），它可以用来包装DNA，把DNA分子送入病毒衣壳（procapsid）里头。
Peixuan Guo等人目前正把奈米马达的概念应用在设计人工RNA奈米装置中，他们已经成功地从RNA形成的模块中建造出3D数组，并且这些3D数组更可以延伸至数个微米(micrometers)，进而搭起奈米制造（nanofabrication）与微米制造（microfabrication）之间的桥梁。而消息已刊登在2004年八月的《奈米通讯期刊》 (Nano Letters)。
Peixuan Guo指出，在生物体内具有各式各样的奈米机器，例如细胞膜上的帮浦(pump)或马达(motor)等，他们正致力在把这些生物体内的奈米装置，拿到外界也就是活体外的环境下来表达，正如同上述的RNA六合体环状结构，就可以用来当成精小但强又有利的奈米马达。而目前这些RNA的3D数组还是处于初期研发的阶段，他们希望未来能够把这些3D数组应用在病理诊断芯片、微小感应器、基因治疗使用的基因输送载体以及电子仪器等研发。
原始论文：
Shu D, Moll D, Deng Z, Mao C, and Guo P. 2004. Bottom-up assembly of RNA arrays and superstructures as potential parts in nanotechnology. Nano Letters 4: 1717-1724. No Longer Just For Biology, RNA Can Now Be Built Into 3-D Arrays
ARLINGTON, Va.?Researchers have coaxed RNA to self-assemble into 3-D arrays, a potential backbone for nanotech scaffolds. These RNA structures can form a wider variety of shapes than double-stranded DNA can and are easier to manipulate than many protein alternatives.
Peixuan Guo of Purdue University and his colleagues report the findings in the August 11, 2004, issue of the journal Nano Letters.
RNA (ribonucleic acid) molecules are best known for implementing the genetic information encoded in DNA (deoxyribonucleic acid). However, instead of using the long molecular strings to carry information, the researchers have achieved new control over RNA and created novel arrays.
By mixing the custom-made RNA strands with other substances, such as magnesium chloride, the researchers were able to get the strands to join into 3-D shapes.
In 1987, Guo discovered that a bacteria-infecting virus possesses a biomolecular nanomotor that requires RNA molecules to function. While determining how RNA works in that motor, he learned to manipulate and control RNA assembly.
Now, Guo and his colleagues have applied that knowledge to building artificial RNA nanostructures, including 搇arge?3-D arrays formed from identical RNA building blocks. Because these arrays extend to several micrometers, far larger than individual RNA strands, they may potentially link nanofabrication with current microfabrication processes.
The researchers hope that the arrays, while still in the earliest stages of development, will one day serve as the scaffolding on which diagnostic chips, tiny sensors, gene delivery vehicles and other nanoscale devices will be mounted or constructed.
From the researchers:
揕iving systems contain a wide variety of nanomachines and ordered structures, including motors, pumps and valves. Our research is devoted to making these machines function outside their native environment.??Peixuan Guo, Purdue University
揥e have discovered a particular type of RNA molecule known as pRNA, or packaging RNA, that forms six-unit rings that can drive a tiny but powerful molecular motor.??Peixuan Guo
揙ur future research will focus on incorporating these nanomachines into nanodevices for such applications as drug or gene delivery, gears for nano-equipment, and intricate arrays and chips for diagnostic devices, sensors and electronics.??Peixuan Guo
揟his report demonstrates that RNA can be used to form a variety of artificial shapes and that we can assemble these shapes into arrays tens of microns in size. Using RNA抯 tendency to self-assemble, we have built the arrays from many thousands of connected RNA building blocks. The arrays are stable and resistant to a wide range of environmental conditions, such as temperature, salt concentration, and pH.??Peixuan Guo
From experts at NSF:
揟he discovery of this viral RNA machine is quite remarkable and provides yet another example of the flexibility and versatility of RNA. Dr. Guo is exploiting the properties of RNA in a new and potentially important way.??Patrick Dennis, Program Director for Microbial Genetics at the National Science Foundation and the officer who oversees Dr. Guo抯 award. 奈米??? [标签:content1][标签:content2]
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作者:admin@医学,生命科学 2011-09-18 05:18
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