The heat released during catalytic turnover enhances the diffusion of an enzyme

Article

关键词: FLUORESCENCE CORRELATION SPECTROSCOPY;    CALORIMETRY;    CATALASE;    PROPULSION;    DRIVEN;   

DOI  :  10.1038/nature14043

来源: SCIE

【 摘 要 】

Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis(1,2). Although this observation has been reported and characterized for several different systems(3-10), the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms(11,12). The ensemble averages involved in traditional bulk calorimetry cannot probe the transient effects that the energy exchanged in a reaction may have on the catalyst. Here we obtain single-molecule fluorescence correlation spectroscopy data and analyse them within the framework of a stochastic theory to demonstrate a mechanistic link between the enhanced diffusion of a single enzyme molecule and the heat released in the reaction. We propose that the heat released during catalysis generates an asymmetric pressure wave that results in a differential stress at the protein-solvent interface that transiently displaces the centre-of-mass of the enzyme (chemoacoustic effect). This novel perspective on how enzymes respond to the energy released during catalysis suggests a possible effect of the heat of reaction on the structural integrity and internal degrees of freedom of the enzyme.

【 授权许可】

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