模擬揭示質子在水中的傳輸由順序氫鍵交換雙重控制

作者：小柯機器人 發(fā)布時間：2024/8/22 21:52:14

本期文章：《自然—化學》：Online/在線發(fā)表

法國巴黎文理研究大學Laage, Damien研究團隊報道，基于神經(jīng)網(wǎng)絡的分子動力學模擬揭示質子在水中的傳輸由順序氫鍵交換雙重控制。相關研究成果于2024年8月20日發(fā)表在《自然—化學》。

水中多余質子的運輸是酸堿化學、生物化學和能源生產(chǎn)的核心。然而，闡明其機制一直具有挑戰(zhàn)性。最近的非線性振動光譜實驗無法用現(xiàn)有的模型來解釋。

該文中，研究人員使用振動光譜計算和基于神經(jīng)網(wǎng)絡的分子動力學模擬來確定質子輸運機制，這些模擬考慮了所有原子的核量子效應。該模擬揭示了具有不同的本征式和宗德爾式氫鍵基序的，兩個穩(wěn)定的質子局域化結構之間的平衡。

質子傳輸遵循由兩次連續(xù)氫鍵交換控制的三步機制：第一步減少質子受體-水配位，導致質子轉移，第二步是限速步驟，通過增加質子供體配位來防止快速反向轉移。這種順序機制與質子擴散的實驗特征一致，解釋了振動光譜中的低活化能和延長的中間壽命。

研究結果對于理解生化和技術系統(tǒng)中的質子動力學至關重要。

附：英文原文

Title: Neural-network-based molecular dynamics simulations reveal that proton transport in water is doubly gated by sequential hydrogen-bond exchange

Author: Gomez, Axel, Thompson, Ward H., Laage, Damien

Issue&Volume: 2024-08-20

Abstract: The transport of excess protons in water is central to acid–base chemistry, biochemistry and energy production. However, elucidating its mechanism has been challenging. Recent nonlinear vibrational spectroscopy experiments could not be explained by existing models. Here we use both vibrational spectroscopy calculations and neural-network-based molecular dynamics simulations that account for nuclear quantum effects for all atoms to determine the proton transport mechanism. Our simulations reveal an equilibrium between two stable proton-localized structures with distinct Eigen-like and Zundel-like hydrogen-bond motifs. Proton transport follows a three-step mechanism gated by two successive hydrogen-bond exchanges: the first reduces the proton-acceptor water coordination, leading to proton transfer, and the second, the rate-limiting step, prevents rapid back-transfer by increasing the proton-donor coordination. This sequential mechanism is consistent with experimental characterizations of proton diffusion, explaining the low activation energy and the prolonged intermediate lifetimes in vibrational spectroscopy. These results are crucial for understanding proton dynamics in biochemical and technological systems.

DOI: 10.1038/s41557-024-01593-y

Source: https://www.nature.com/articles/s41557-024-01593-y

期刊信息

Nature Chemistry：《自然—化學》，創(chuàng)刊于2009年。隸屬于施普林格·自然出版集團，最新IF：24.274

**官方網(wǎng)址：**https://www.nature.com/nchem/

**投稿鏈接：**https://mts-nchem.nature.com/cgi-bin/main.plex