炭水化物の合成は,ミネラル誘導のプレバイオティックサイクルで行われます
Hyo-Joong Kim1, Alonso Ricardo, Heshan I Illangkoon
1Foundation for Applied Molecular Evolution, Westheimer Institute for Science and Technology, P.O. Box 13174, Gainesville, Florida 32604, USA.
Journal of the American Chemical Society
|May 11, 2011
まとめ
生命の起源には,ボラートやモリブデートなどの鉱物触媒を通じて炭水化物の形成が関与している可能性があります. これらの鉱物は,初期の地球条件下でも,RNAにとって不可欠なペントース糖の生成を促進しました.
科学分野:
- プレビオティック化学と生命の起源の研究.
- 初期の地球環境の地球化学.
- 炭水化物の形成の生化学. 炭水化物の形成の生化学.
背景:
- 生命の起源に関する"RNA-first"モデルには,炭水化物の形成のありそうな経路が必要である.
- 以前のシナリオは,砂糖の合成と生存を"手放す"ことを説明するのに苦労しました.
- ペントース (五炭素糖) の形成は,RNAのような遺伝子システムにとって極めて重要です.
研究 の 目的:
- 炭水化物のプレバイオティック合成のための"手放す"シナリオを調査する.
- 必須糖の形成を促進する鉱物触媒を特定する.
- 初期の地球条件下でペントース形成の経路を探求する.
主な方法:
- 炭水化物の前代謝の詳細な化学分析.
- フォーマルデヒドとグリコールアルデヒドから始まる"手を離す"実験.
- ボレート,モリブデート,およびカルシウム鉱物を用いた鉱物触媒の調査.
主要な成果:
- ボレート,モリブデート,およびカルシウム鉱物は,テトロス,ヘプトス,ペントス (リボスを含む) の形成を導く.
- ペントースは,湿ったCO2と電気的な放電の下で,初期の地球で安定したボラート複合体として形成された可能性が高い.
- アルドテトロスは安定しているものの,初期の地球経路によって好まれていない.
結論:
- RNAにとって不可欠なペントース糖は,鉱物触媒を用いて初期の地球条件下で無生物的に形成される可能性がある.
- 潜水などの地質学的過程で潜在的に利用可能なボラートとモリブダートは,重要な役割を果たしました.
- 鉱物媒介経路は,生命の起源の研究における炭水化物形成の課題に有効な解決策を提供します.
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