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

Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis. Although this observation has been reported and characterized for several different systems, 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. 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). We find 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.
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Univ. of California, Berkeley, CA (United States). California Institute for Quantitative Biosciences
  2. Univ. of California, Berkeley, CA (United States). California Institute for Quantitative Biosciences; Univ. of Chile, Santiago (Chile)
  3. Indiana University-Purdue University, Indianapolis, IN (United States)
  4. Univ. of California, Berkeley, CA (United States). California Institute for Quantitative Biosciences; Univ. of California, Berkeley, CA (United States). Dept. of Molecular and Cell Biology
  5. Indiana University-Purdue University, Indianapolis, IN (United States); Indiana University School of Medicine, IN (United States)
  6. Univ. of California, Berkeley, CA (United States). California Institute for Quantitative Biosciences; Univ. of California, Berkeley, CA (United States). Dept. of Molecular and Cell Biology; Univ. of California, Berkeley, CA (United States). Jason L. Choy Laboratory of Single-Molecule Biophysics and Department of Physics; Univ. of California, Berkeley, CA (United States). Howard Hughes Medical Institute; Univ. of California, Berkeley, CA (United States). Kavli Energy Nano Sciences Institute
Publication Date:
OSTI Identifier:
1257853
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Nature (London)
Additional Journal Information:
Journal Name: Nature (London); Journal Volume: 517; Journal Issue: 7533; Journal ID: ISSN 0028-0836
Publisher:
Nature Publishing Group
Research Org:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES