Water Dynamics Around Proteins: T- and R-States of Hemoglobin and Melittin
Name
2006.14905.pdf
Description
Accepted version
Size
3.15 MB
Format
Unknown
Checksum (MD5)
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Author(s)
Pezzella, Marco
El Hage, Krystel
Niesen, Michiel JM
Shin, Sucheol
Willard, Adam P
Meuwly, Markus
Karplus, Martin
Date Issued
2020
Journal
Journal of Physical Chemistry B
Publisher
American Chemical Society (ACS)
Version
Author's final manuscript
Abstract
Copyright © 2020 American Chemical Society. The water dynamics, as characterized by the local hydrophobicity (LH), is investigated for tetrameric hemoglobin (Hb) and dimeric melittin. For the T0 to R0 transition in Hb, it is found that LH provides additional molecular-level insight into the Perutz mechanism, i.e., the breaking and formation of salt bridges at the α1/β2 and α2/β1 interface is accompanied by changes in LH. For Hb in cubic water boxes with 90 and 120 Å edge length it is observed that following a decrease in LH as a consequence of reduced water density or change of water orientation at the protein/water interface the α/β interfaces are destabilized; this is a hallmark of the Perutz stereochemical model for the T to R transition in Hb. The present work thus provides a dynamical view of the classical structural model relevant to the molecular foundations of Hb function. For dimeric melittin, earlier results by Cheng and Rossky [ Nature 1998, 392, 696-699[ are confirmed and interpreted on the basis of LH from simulations in which the protein structure is frozen. For the flexible melittin dimer, the changes in the local hydration can be as much as 30% greater than for the rigid dimer, reflecting the fact that protein and water dynamics are coupled.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1021/ACS.JPCB.0C04320
