McAnally Mason, Bocková Jana, Turner Andrew M, Hara Nana, Mikhnova Daria, Meinert Cornelia, Kaiser Ralf I
Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.
W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.
Proc Natl Acad Sci U S A. 2025 Apr 29;122(17):e2501839122. doi: 10.1073/pnas.2501839122. Epub 2025 Apr 21.
The molecular framework for protometabolism-chemical reactions in a prebiotic environment preceding modern metabolism-has remained unknown in evolutionary biology. Mono-, di-, and tricarboxylic acids that comprise contemporary metabolism, such as the Krebs cycle, are of particular prebiotic relevance and are theorized to predate life on Earth. Researchers have struggled to unravel the molecular origins of respiration, with theories pointing toward abiotic origins later co-opted by the earliest living organisms; however, the molecular network of these molecules has remained elusive. Recent detections of carboxylic acids linked to the Krebs cycle on the Ryugu asteroid and Murchison meteorite rekindled interest in their extraterrestrial origins. Replicating conditions analogous to the environment of dense molecular clouds in laboratory simulation experiments, our work provides compelling evidence on the abiotic synthesis of the complete suite of biorelevant molecules central to the Krebs cycle. The opportunity for these biomolecules forming in deep space could provide molecular origins of protometabolism on early Earth and also provide the molecular feedstock to worlds beyond our own.
在前现代新陈代谢之前的益生元环境中的原代谢化学反应的分子框架，在进化生物学中一直不为人知。构成当代新陈代谢的单羧酸、二羧酸和三羧酸，如三羧酸循环，具有特殊的益生元相关性，理论上被认为早于地球上的生命出现。研究人员一直在努力解开呼吸作用的分子起源，各种理论都指向非生物起源，这些起源后来被最早的生物体所采用；然而，这些分子的分子网络仍然难以捉摸。最近在龙宫小行星和默奇森陨石上检测到与三羧酸循环相关的羧酸，重新引发了人们对它们外星起源的兴趣。通过在实验室模拟实验中复制类似于致密分子云环境的条件，我们的工作为三羧酸循环核心的一整套与生物相关分子的非生物合成提供了令人信服的证据。这些生物分子在深空中形成的可能性，可能为早期地球上原代谢的分子起源提供依据，也为我们星球之外的世界提供分子原料。
