{"id":2514,"date":"2015-02-08T06:26:21","date_gmt":"2015-02-08T06:26:21","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=2514"},"modified":"2015-02-08T06:26:21","modified_gmt":"2015-02-08T06:26:21","slug":"diamonds-could-help-bring-proteins-into-focus","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/diamonds-could-help-bring-proteins-into-focus\/","title":{"rendered":"Diamonds could help bring proteins into focus"},"content":{"rendered":"

New technique could use tiny diamond defects to reveal unprecedented detail of molecular structures.<\/strong><\/em><\/span><\/p>\n

\"Nitrogen<\/a>
Nitrogen vacancy (NV) centers in diamond could potentially determine the structure of single protein molecules at room temperature. Here the NV center is 2 to 3 nanometers below the surface, and the protein molecule is placed above it.<\/figcaption><\/figure>\n

CAMBRIDGE, Mass–Proteins are the building blocks of all living things, and they exist in virtually unlimited varieties, most of whose highly complex structures have not yet been determined. Those structures could be key to developing new drugs or to understanding basic biological processes.<\/span><\/p>\n

But figuring out the arrangement of atoms in these complicated, folded molecules usually requires getting them to form crystals large enough to be observed in detail \u2014 and for many proteins, that is either impossible or dauntingly difficult.<\/span><\/p>\n

Now a new technique being developed by researchers at MIT and elsewhere shows great promise for producing highly detailed images of individual proteins, no matter how complicated their structure, without the need for crystallization. The findings are described in the journal\u00a0Physical Review X<\/em>\u00a0by MIT graduate student Ashok Ajoy, postdoc Ulf Bissbort, associate professor of nuclear science and engineering Paola Cappellaro, and others at MIT, the Singapore University of Technology and Design, and Harvard University.<\/span><\/p>\n

The technique makes use of microscopic defects within the crystal structure of diamond \u2014 defects that can be induced, in a controlled way, in the lab. These defects, called nitrogen-vacancy (NV) centers, occur when nitrogen atoms are introduced into the crystal structure, each replacing one carbon atom in a perfectly spaced diamond lattice.<\/span><\/p>\n

Such lattices may also include naturally occurring vacancies \u2014 imperfections where a carbon atom is missing from its normal place in the lattice. When a nitrogen atom and a vacancy come together, they form an NV center, which can be harnessed to detect the position and attributes \u2014 specifically, the spin states \u2014 of protons and electrons in atoms placed very close to them.<\/span><\/p>\n

That\u2019s done by shining laser light at the diamond surface, which causes the NV centers to fluoresce. By detecting and analyzing the emitted light, it is possible to reconstruct details of the spin of nearby particles.<\/span><\/p>\n

The ability to use NV centers in diamond has developed in the last few years, Ajoy says, and many groups are now working to make use of them for applications in quantum computation and quantum communication. When the NV centers are very close to a diamond\u2019s surface \u2014 within a few nanometers \u2014 they can also be used to sense the spin states of particles within a molecule placed on the surface. The individual atoms and their positions can then, in principle, be detected and mapped out, revealing the molecular structure.<\/span><\/p>\n

The idea is to \u201cplace a biological molecule on top of the diamond, and try to determine its structure,\u201d Ajoy explains. With proteins, \u201cthe structure and function are closely related,\u201d he says, so being able to map out that structure precisely could help in understanding both how some basic biological processes work, and how new drugs might be developed to interact with specific molecular targets.<\/span><\/p>\n

\u201cIt could help in developing something that fits on or around [a target molecule], or blocks it,\u201d Ajoy says. \u201cThe first step is to know the structure.\u201d<\/span><\/p>\n

Efforts to decode the molecular structure of proteins have mostly used X-ray crystallography, transmission electron microscopy, or nuclear magnetic resonance. But all of these methods require large sample volumes \u2014 for example, X-ray diffraction requires aggregating the molecules as crystals \u2014 so none of them can be used to study individual molecules. This greatly limits the applicability of such techniques.<\/span><\/p>\n

\u201cThere are many molecules where this doesn\u2019t work out, because you can\u2019t grow the crystals, or they are very hard to grow,\u201d Ajoy says. \u201cFor these molecules, our method might be useful because you don\u2019t need the crystals, you just need a single molecule.\u201d<\/span><\/p>\n

What\u2019s more, while other techniques require specialized conditions such as very low temperatures or a vacuum, the new technique \u201cperhaps can determine structure at room temperature, under ambient conditions,\u201d he says.<\/span><\/p>\n

The work so far is theoretical; the next step, which the team has already begun, is to produce actual images based on this technique. \u201cWe started building this setup a year ago, and we have preliminary experiments,\u201d Ajoy says. Actual images of molecules are probably still a few years away, he says.<\/span><\/p>\n

In addition to Ajoy, Cappellaro, and Bissbort, the team included professor of physics Mikhail Lukin and senior lecturer Ronald Walsworth, both of Harvard University. The work was supported by the U.S. Army Research Office and the Defense Advanced Research Projects Agency.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

New technique could use tiny diamond defects to reveal unprecedented detail of molecular structures. CAMBRIDGE, Mass–Proteins are the building blocks of all living things, and they exist in virtually unlimited varieties, most of whose highly complex structures have not yet been determined. Those structures could be key to developing new drugs or to understanding basic […]<\/p>\n","protected":false},"author":6,"featured_media":2515,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,28],"tags":[],"class_list":["post-2514","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-other","category-techbiz"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01-300x200.jpg",300,200,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",600,400,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",600,400,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",540,360,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",95,63,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",639,426,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",96,64,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/02\/MIT-Diamond-Microscope-01.jpg",150,100,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Other<\/a> Tech<\/a>","tag_info":"Tech","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/2514","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=2514"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/2514\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/2515"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=2514"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=2514"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=2514"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}