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天の川の中心部に近い鏡像分子は生命の起源の兆しを与えます
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9:54 EDTでNSIKAN AKPAN 2016年6月15日BY
キラル分子は、生命に不可欠であると私たちの銀河の中心付近の深宇宙での発見は、地球上の生命は、キーの生物学的機能を実行するために特定の利き手に依存している理由の科学者が理解するのに役立つことがあります。ここでは、マウナケア山頂に湖ワイアウ以上の天の川銀河中心上昇。ブレットA.マクガイアによる写真
キラル分子は、生命に不可欠であると私たちの銀河の中心付近の深宇宙での発見は、地球上の生命は、キーの生物学的機能を実行するために特定の利き手に依存している理由の科学者が理解するのに役立つことがあります。
ここでは、マウナケア山頂に湖ワイアウ以上の天の川銀河中心上昇。ブレットA.マクガイアによる写真
政治家と同様に、化学分子は、左または右に傾くことができます。いくつかの化合物展示利き手 - そのアーキテクチャは、互いの鏡像である二つの状態のいずれかに組み立てることができます。このような生物学的人生のいくつかのコンポーネントの場合です。今、初めて、天文学者はキラリティー（発音は「KAI-RAL-性」）として知られている2つの-facednessのこのブランドを持つ空間での化合物を、発見しました。 、およびプロキシによって生命の起源を - 新しい発見は、このプロパティの起源を研究するための星間実験室のための段階を設定します。
人生は他の上分子内に1-利き手を選ばれた理由生物学における最大の謎の一つです。「人生は他の上分子内に1-利き手を選ばれた理由生物学における最大の謎の一つである、「のブレット・マクガイアは言いました発見の背後にあるプロジェクトを主導共同バージニア州のアメリカ国立電波天文台。 「我々は、左利きのアミノ酸を使用して、私たちの糖のほとんどは右利きです。」
人生を変えるキラリティーの例は、どこにでもあります。化学1-利き手は、キノコは毒であるかどうか、または果実はオレンジやレモンのようなにおいがするかどうかを決定することができます。そのキラルパートナーがそうではない一ナトリウムL-グルタミン酸（MSG）は、独特の旨味を運びます。医薬品メーカーが原因化学双子に私たちの体」、異種、しばしば深刻な反応をキラリティーに細心の注意を払います。医師がその双子を持つ不純物が先天性欠損症を引き起こす可能性があることを実現するまで1950年代後半では、妊婦は、つわりのためにサリドマイドを取りました。
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匂いがどのように見えますか
これらの一方的な関係は、そう、それは彼らが発生したか特定するのは難しいことを地球上で十分に確立されています。
そこで2008年に、アメリカ国立電波天文台は答えをコスモスを探し始めました。天文学者は射手座B2（N）、390光年離れ星間ガスの巨大な雲に向かってウェストバージニア州のグリーンバンク望遠鏡を目的としました。
「射手座は、複雑な有機分子の完全である、「ブランドン・キャロル、物理的なカリフォルニア工科大学で化学者、プロジェクトの共同リーダーは言いました。 「分子が空間内で検出された場合、それはほぼ確実に座で検出されています。」
プロピレンオキシド - 十年前、チームはキラル化学の最初のヒントを検出しました。しかし、その後、彼らは暗礁に乗り上げます。
科学者たちは、私たちの銀河系の中心付近の射手座（SGR）B2、大質量星形成領域で「左利き」分子（プロピレンオキサイド）の第1の検出を行いました。プロピレンオキシドの二つの「左利き」のバージョンが示されています。 「R」および「S」の名称は、ラテン語の用語の直筋（右）と不吉な（左）のためのものです。 B.サクストン、N.E.によって提供されたデータから、NRAO / AUI / NSFによる写真カシム、海軍研究所、スローン・デジタル・スカイサーベイ
科学者たちは、私たちの銀河系の中心付近の射手座（SGR）B2、大質量星形成領域で「左利き」分子（プロピレンオキサイド）の第1の検出を行いました。プロピレンオキシドの二つの「左利き」のバージョンが示されています。 「R」および「S」の名称は、ラテン語の用語の直筋（右）と不吉な（左）のためのものです。 B.サクストン、N.E.によって提供されたデータから、NRAO / AUI / NSFによる写真カシム、海軍研究所、スローン・デジタル・スカイサーベイ
マクガイアとキャロルが再び空をスキャンすることによって送信を確認しようとすると、望遠鏡は、ノイズの束を拾いました。グリーンバンク望遠鏡は、高感度で、一度にスペースの大きな塊を観察します。しかし、視線の元の行は、完全に放送衛星からの干渉によって隠さ。
「現代の情報通信技術の出現は、私たちが宇宙で物事を検出するために使用したいスペクトルのより多くのことを意味ランダム放送によってブロックされている、「キャロルは言いました。それは家庭や携帯電話塔内無線LANルータのようなものが科学のために禁止されている国家ラジオクワイエットゾーン、に座っているので、グリーンバンク望遠鏡はユニークです。しかし、これらの規制は、衛星からの電波干渉を防ぐことはできません。
だから、チームはオーストラリア、パークス天文台になりました。 「それは、衛星放送によってブロックされたが、我々は、時間の申請お金を見つけ、その後、最終的にそこに行かなければならなかったされていません。それはそれらのものを反復処理するために数年を要した、「キャロルは言いました。
射手座のガス雲でバレリーナのように回転して、酸化プロピレンのミラーリングバージョン - パークス天文台は、元の信号を確認しました。分子は、エンドオーバーエンドをタンブリングされ、それは特徴的な信号を生成するものだ、マグワイアは述べています。
あなたはマットレスパッドや他の合成発泡体の内部でそれを見つけることができますが、プロピレンオキシドは、地球上の生物における役割を果たしていません。だから、どのようにこの化合物は、人生の初期段階のための青写真をスケッチのでしょうか？
私たちが今までの人生を持って前に太陽系と地球のための責任ガス雲は何百万年もの間進化しました。
星や惑星が形成するために、何百万年を取ります。私たちが今までの人生を持って前に太陽系と地球のための責任ガス雲は何百万年もの間進化しました。射手座B2Nのような巨大な雲は星が活発に形成されたガスと塵が含まれている、McGuireさんは言いました。惑星と太陽光発電システムは、最終的にはそれらの星の一部または全部を周囲に形成することになります。だから、その雲の中の化学物質は、最終的にそれらの惑星に組み込まれます。
ベン・マッコール、イリノイ大学の天体物理学者」の一つもっともらしい理論は太陽系が形成されており、若い地球上の生化学的プロセスは、最初の星間過剰、ことを増幅させた前の左利きの分子の小過剰が星間空間で生産されたということです」新しい研究に関与していない人は、ワシントン・ポスト紙に語りました。 「この理論は、スペースだけでキラル分子を観察することによってテストすることができ、そしてこの作品は、そのようなテストのための段階を設定します。」
キャロルとマグワイアは、プロピレンオキシドが左利きされてどのくらいの右利き対射手座に測定するために計画しています。えこひいきがある場合、彼らはバランスを傾けている星間プロセスを探すことができます。単一平面に進むか、光 - 一つの可能性は偏光です。
「これらの光波は左利きすることができるか、または右利きすぎて、「キャロルは言いました。 「右利きの光が...右利きの化学分子とより強く相互作用すると、左よりも右利きの分子を破壊します。」
彼らは過剰右または左回りの分子が存在する領域では、余分な偏光を検出した場合、それは化学的バイアスが発信方法の理論的根拠を提供するであろう。それは何百万年を要するので、彼らは時間をかけて、単一のクラウドでこれらのプロセスを観察することはできません。しかし、満期の異なる段階で個々の星系を見ることによって、チームはプレバイオティクスの進化の初期段階を明らかにすることができました。
Mirror-image molecule near Milky Way’s heart gives glimmer of life’s origins
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BY NSIKAN AKPAN June 15, 2016 at 9:54 AM EDT
Chiral molecules are essential for life and a discovery in deep space near the center of our galaxy may help scientists understand why life on Earth relies on a certain handedness to perform key biological functions. Here, the Milky Way and Galactic Center rise over Lake Waiau on the summit of Mauna Kea. Photo by Brett A. McGuire
Chiral molecules are essential for life and a discovery in deep space near the center of our galaxy may help scientists understand why life on Earth relies on a certain handedness to perform key biological functions.
Here, the Milky Way and Galactic Center rise over Lake Waiau on the summit of Mauna Kea. Photo by Brett A. McGuire
Like politicians, chemical molecules can lean left or right. Some compounds exhibit handedness — their architecture can assemble into one of two states that are mirror-images of each other. Such is the case for several components of biologic life. Now, for the first time, astronomers have discovered a compound in space with this brand of two-facedness, known as chirality (pronounced “kai-ral-ity”). The new discovery sets the stage for an interstellar laboratory for studying the origins of this property — and by proxy, the origins of life.
One of the biggest mysteries in biology is why life has chosen one-handedness in a molecule over the other.“One of the biggest mysteries in biology is why life has chosen one-handedness in a molecule over the other,” said Brett McGuire of the National Radio Astronomy Observatory in Virginia who co-led the project behind the discovery. “We use left-handed amino acids and most of our sugars are right-handed.”
Examples of life-altering chirality are everywhere. Chemical one-handedness can dictate whether a mushroom is poisonous, or whether a fruit smells like oranges or lemons. Monosodium L-glutamate (MSG) carries a distinctive umami taste, while its chiral partner does not. Drug makers pay close attention to chirality due to our bodies’ disparate, and often severe, reactions to chemical twins. In the late 1950s, expectant mothers took thalidomide for morning sickness, until doctors realized that impurities with its twin can cause birth defects.
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These unilateral relationships are so well-established on Earth that it’s hard to pinpoint how they arose.
So in 2008, the National Radio Astronomy Observatory began searching the cosmos for answers. The astronomers aimed the Green Bank Telescope in West Virginia toward Sagittarius B2(N), a giant cloud of interstellar gas located 390 light-years away.
“Sagittarius is full of complex organic molecules,” said Brandon Carroll, a physical chemist at the California Institute of Technology and the project’s co-leader. “If a molecule has been detected in space, then it’s almost certainly been detected in Sagittarius.”
A decade ago, the team detected the first hints of a chiral chemical — propylene oxide. But then, they hit a snag.
Scientists made first detection of a "handed" molecule (propylene oxide) in Sagittarius (Sgr) B2, a massive star-forming region near the center of our galaxy. The two "handed" versions of propylene oxide are illustrated. The "R" and "S" designations are for the Latin terms rectus (right) and sinister (left). Photo by B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory, Sloan Digital Sky Survey
Scientists made first detection of a “handed” molecule (propylene oxide) in Sagittarius (Sgr) B2, a massive star-forming region near the center of our galaxy. The two “handed” versions of propylene oxide are illustrated. The “R” and “S” designations are for the Latin terms rectus (right) and sinister (left). Photo by B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory, Sloan Digital Sky Survey
When McGuire and Carroll tried to confirm the transmission by scanning the skies again, the telescope picked up a bunch of noise. The Green Bank Telescope observes large chunks of space at once, with high sensitivity. But the original line of sight completely obscured by interference coming from broadcast satellites.
“The advent of modern telecommunications technology means more and more of the spectrum that we like to use to detect things in space are blocked by random broadcast,” Carroll said. The Green Bank Telescope is unique because it sits in a national radio quiet zone, where things like WiFi routers in homes and cellphone towers are banned for the sake of science. But these regulations don’t prevent radio interference from satellites.
So, the team turned to Australia and the Parkes Observatory. “It isn’t blocked by satellite broadcasts, but we had to apply for time, find the money and then eventually go down there. It took a couple of years to iterate through those things,” Carroll said.
The Parkes Observatory confirmed the original signal — mirrored versions of propylene oxide, spinning like ballerinas in the Sagittarius gas cloud. The molecule is tumbling, end over end, and that’s what produces the characteristic signal, McGuire said.
Propylene oxide doesn’t play a role in organisms on Earth, although you can find it inside mattress pads and other synthetic foams. So, how might this compound sketch a blueprint for the early stages of life?
The gas cloud responsible for our solar system and Earth was evolving for millions of years before we ever got life.
Stars and planets take millions of years to form. The gas cloud responsible for our solar system and Earth was evolving for millions of years before we ever got life. Giant clouds like Sagittarius B2N contain gas and dust where stars are actively forming, McGuire said. Planets and solar systems will ultimately form around some or all of those stars. So, the chemical materials in that cloud will eventually be incorporated into those planets.
“One plausible theory is that a small excess of left-handed molecules was produced in interstellar space before our solar system was formed, and biochemical processes on the young Earth amplified that initial interstellar excess,” Ben McCall, an astrophysicist from the University of Illinois who wasn’t involved in the new study, told The Washington Post. “This theory can only be tested by observing chiral molecules in space, and this work sets the stage for such tests.”
Carroll and McGuire plan to measure how much propylene oxide is left-handed versus right-handed in Sagittarius. If there is a favoritism, then they can look for interstellar processes that are tipping the balance. One possibility is polarized light — or light that travels in a single plane.
“These light waves can be left-handed or right-handed too,” Carroll said. “Right-handed light will interact more strongly with right-handed chemical molecules…and will destroy more right-handed molecules than left.”
If they detect extra polarized light in a region where there is excess right- or left-handed molecules, then it would provide a rationale for how the chemical bias originated. They can’t observe these processes in a single cloud over time because it takes millions of years. But by looking at individual star systems at different stages of maturity, the team could clarify the early stages of prebiotic evolution.
“We want to understand the mechanisms that might drive a little more right- and left-handed molecules to be formed, not just in Sagittarius but everywhere.” Carroll said. The study was published Tuesday in Science Magazine.
http://www.pbs.org/newshour/updates/mirror-image-molecule-found-near-milky-ways-heart-gives-glimmer-of-lifes-origins-chirality/
Scientists Detect First Mirror Image Molecule in Deep Space
By John Raphael Jun 15, 2016 04:25 AM EDT
Chiral Molecule Found Near Galactic Center
Scientists applaud the first detection of a "handed" molecule, (propylene oxide) in interstellar space. It was detected, primarily with the NSF's Green Bank Telescope, near the center of our Galaxy in Sagittarius (Sgr) B2, a massive star-forming region. Propylene oxide is one of a class of so-called "chiral" molecules -- molecules that have an identical chemical composition, but right- and left-handed versions. Chiral molecules are essential for life and their discovery in deep space may help scientists understand why life on Earth relies on a certain handedness to perform key biological functions. Sgr A* in this image indicates the supermassive black hole at the center of our Galaxy. The white features in the composite image are the bright radio sources in the center of our Galaxy as seen with the VLA. The background image is from the Sloan Digital Sky Survey. The two "handed" versions of propylene oxide are illustrated. The "R" and "S" designations are for the Latin terms rectus (right) and sinister (left).
(Photo : B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory, Sloan Digital Sky Survey)
Astrochemists from the California Institute of Technology (Caltech) have detected the first evidence of chiral molecule in the interstellar space 28,000 light years away from Earth.
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Chiral molecules are two enantiomeric forms that are almost identical but are actually different molecules. These molecules have may behave same way physically in terms of melting, freezing, and absorbing light. However, each of the "twin" molecules may react chemically with other substances in different ways. Chiral molecules are known to be "handed" molecules and can be typically found in meteors and comets, but never been detected before in interstellar space.
The chiral molecule found in the stellar space is the propylene oxide (CH3CHCH2O), which is being used on Earth to make polyethylene plastics. It is detected near the center of our Milky Way galaxy in a star-forming cloud of dust and gas known as Sagittarius B2 (Sgr B2).
"Propylene oxide is among the most complex and structurally intricate molecules detected so far in space," said Brandon Carroll, a chemistry graduate student at Caltech, in a statement. "Detecting this molecule opens the door for further experiments determining how and where molecular handedness emerges and why one form may be slightly more abundant than the other."
However, researchers can't determine if the propylene oxide detected in the Sgr B2 were left-handed, right-handed or both.
For their study, which was published in the journal Science, researchers used the National Science Foundation's Green Bank Telescope in West Virginia and the Parkes radio telescope in Australia.
Data from the radio telescope suggests the existence of propylene oxide in a shell of gas outside the core of Sgr B2. These findings support previous notions proposing that complicated molecules can be formed on ice grains in diffuse clouds of interstellar gas and dust.
The discovery of chiral molecules in interstellar space can help researchers understand how chiral molecules from space may have crashed in the Earth leading to the formation of life.
"This [discovery] is going to provide us with a laboratory to try to test theories about the role that chiral molecules played in the origins of life here on Earth and how that chirality might play a role in the origins of life elsewhere in the galaxy," explained Brett McGuire, a researcher at the National Radio Astronomy Observatory in Virginia, in a press conference.
http://www.natureworldnews.com/articles/23709/20160615/scientists-detects-first-mirror-image-molecule-deep-space.htm
'Twisty' Molecule Essential to Life Spotted in Deep Space For 1st Time
By Sarah Lewin, Staff Writer | June 14, 2016 03:01pm ET
494 99 28 52 30 MORE
Molecules with "right-handed" and "left-handed" versions are essential to all life on Earth, and have been found in meteors and comets. Now, for the first time, one has been spotted in interstellar space.
Discovering such molecules in deep space, called chiral molecules, can help researchers understand the development of life on Earth, which is rich in those complex molecules — what presenters at the American Astronomical Society's summer meeting in San Diego called "life's first handshake." The discovery is explained in this new video by Science Magazine.
"This [discovery] is going to provide us with a laboratory to try to test theories about the role that chiral molecules played in the origins of life here on Earth and how that chirality might play a role in the origins of life elsewhere in the galaxy," Brett McGuire, a researcher at the National Radio Astronomy Observatory in Virginia and co-first author on the new work, said at the AAS press conference today (June 14). [50 Fabulous Deep-Space Nebula Photos]
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The researchers used the National Science Foundation's Green Bank Telescope in West Virginia and the Parkes radio telescope in Australia to pinpoint the intricate molecule propylene oxide near the center of the Milky Way, in the mammoth star-forming cloud of gas called Sagittarius B2.
For the first time, scientists have measured a "handed" molecule in interstellar space. The molecule, propylene oxide, comes in both "left-handed" and "right-handed" varieties. It was found in the huge star-forming cloud of gas Sagittarius B2, pictured here alongside Sagittarius A*, the supermassive black hole at the Milky Way's center.
For the first time, scientists have measured a "handed" molecule in interstellar space. The molecule, propylene oxide, comes in both "left-handed" and "right-handed" varieties. It was found in the huge star-forming cloud of gas Sagittarius B2, pictured here alongside Sagittarius A*, the supermassive black hole at the Milky Way's center.
Credit: B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory, Sloan Digital Sky Survey
Science of chirality
Key biological reactions on Earth rely on molecules with the property called chirality — compounds that can form in two different varieties that are mirror images of each other, sort of like left and right hands. Though the molecules are made of the same components, it's impossible to flip one around to make it exactly match the other.
On Earth, most chiral molecules exist largely in a single formation, even though when you create them chemically from scratch, both varieties will form. Many chemical reactions only work when molecules of a particular "handedness" interact with each other.
"When you shake somebody's hand, your right hand shakes another right hand, and it forms that nice, interlocking gesture; if you try to shake a left hand with your right hand it's a little awkward because the interaction is different," McGuire said. "Chiral molecules work the same way."
(For instance, the chemical carvone will smell like spearmint in one configuration, but its mirror image smells like caraway.)
Processes powered by one particular "handedness" will produce more of that same type of molecule, and molecules with the wrong "handedness" won't work at all in many biological systems. Because of that, most of the important chiral molecules on Earth, like amino acids, are all the same "handedness" as each other. But scientists don't know how the Earth came to favor particular varieties to start with.
A cosmic handshake
Researchers have found complex organic molecules on meteorites and comets, including chiral molecules which have shown a slight preference for one handedness over the other. Just a few percent excess "could be the tipping point that pushed life in a single direction, and that gave life the push it needed to, say, use only left-handed amino acids," Brandon Carroll, the work's other first author and a chemistry graduate student at California Institute of Technology, said at the conference.
"But if we want to understand where and how this started, we have to go even further back than the meteorites; we have to look at the gas clouds where these molecules formed from," he added.
In this case, they spotted a hefty dose of propylene oxide in distant interstellar space — about 80 percent Earth's mass, which at room temperature would take up five and a half earths' worth of space, Carroll said.
If chiral materials had existed already in the cloud of gas and dust from which the solar system formed, or if they'd fallen to Earth on a meteorite or had been carried on a comet, that could explain Earth's preference — and also help explain the process of life's first formation on Earth.
The researchers' measurements of the propylene oxide don't reveal which handedness the far-off molecules have; the data from the radio telescopes show only the composition, not how each molecule is put together. However, future work could try to determine that by watching how the molecules interact with polarized light, which corkscrews in a particular direction, the researchers said.
"Now it gives us a testbed, some molecule we can actually go back and perform the far more complicated and challenging observations necessary to detect the handedness," Carroll said. "That's what we're really excited about, because that will let us start to test theories about processes that might actually have chiral preference in the interstellar medium."
The new work was detailed June 14 in the journal Science.
Email Sarah Lewin at slewin@space.com or follow her @SarahExplains. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.
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http://www.space.com/33167-twisty-chiral-molecule-first-found-interstellar-space.html
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