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Slow conformational changes in the rigid and highly stable chymotrypsin inhibitor 2

Gavrilov, Yulian LU ; Prestel, Andreas ; Lindorff-Larsen, Kresten and Teilum, Kaare LU (2023) In Protein Science 32(4).
Abstract

Slow conformational changes are often directly linked to protein function. It is however less clear how such processes may perturb the overall folding stability of a protein. We previously found that the stabilizing double mutant L49I/I57V in the small protein chymotrypsin inhibitor 2 from barley led to distributed increased nanosecond and faster dynamics. Here we asked what effects the L49I and I57V substitutions, either individually or together, have on the slow conformational dynamics of CI2. We used 15N CPMG spin relaxation dispersion experiments to measure the kinetics, thermodynamics, and structural changes associated with slow conformational change in CI2. These changes result in an excited state that is populated to... (More)

Slow conformational changes are often directly linked to protein function. It is however less clear how such processes may perturb the overall folding stability of a protein. We previously found that the stabilizing double mutant L49I/I57V in the small protein chymotrypsin inhibitor 2 from barley led to distributed increased nanosecond and faster dynamics. Here we asked what effects the L49I and I57V substitutions, either individually or together, have on the slow conformational dynamics of CI2. We used 15N CPMG spin relaxation dispersion experiments to measure the kinetics, thermodynamics, and structural changes associated with slow conformational change in CI2. These changes result in an excited state that is populated to 4.3% at 1°C. As the temperature is increased the population of the excited state decreases. Structural changes in the excited state are associated with residues that interact with water molecules that have well defined positions and are found at these positions in all crystal structures of CI2. The substitutions in CI2 have only little effect on the structure of the excited state whereas the stability of the excited state to some extent follows the stability of the main state. The minor state is thus most populated for the most stable CI2 variant and least populated for the least stable variant. We hypothesize that the interactions between the substituted residues and the well-ordered water molecules links subtle structural changes around the substituted residues to the region in the protein that experience slow conformational changes.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
conformational dynamics, NMR spectroscopy, nuclear spin relaxation, protein stability
in
Protein Science
volume
32
issue
4
article number
e4604
publisher
The Protein Society
external identifiers
  • pmid:36807681
  • scopus:85152664332
ISSN
0961-8368
DOI
10.1002/pro.4604
language
English
LU publication?
yes
id
d360dc01-6276-4b31-b598-884e17fc4a5b
date added to LUP
2023-07-13 10:58:43
date last changed
2024-04-19 23:21:28
@article{d360dc01-6276-4b31-b598-884e17fc4a5b,
  abstract     = {{<p>Slow conformational changes are often directly linked to protein function. It is however less clear how such processes may perturb the overall folding stability of a protein. We previously found that the stabilizing double mutant L49I/I57V in the small protein chymotrypsin inhibitor 2 from barley led to distributed increased nanosecond and faster dynamics. Here we asked what effects the L49I and I57V substitutions, either individually or together, have on the slow conformational dynamics of CI2. We used <sup>15</sup>N CPMG spin relaxation dispersion experiments to measure the kinetics, thermodynamics, and structural changes associated with slow conformational change in CI2. These changes result in an excited state that is populated to 4.3% at 1°C. As the temperature is increased the population of the excited state decreases. Structural changes in the excited state are associated with residues that interact with water molecules that have well defined positions and are found at these positions in all crystal structures of CI2. The substitutions in CI2 have only little effect on the structure of the excited state whereas the stability of the excited state to some extent follows the stability of the main state. The minor state is thus most populated for the most stable CI2 variant and least populated for the least stable variant. We hypothesize that the interactions between the substituted residues and the well-ordered water molecules links subtle structural changes around the substituted residues to the region in the protein that experience slow conformational changes.</p>}},
  author       = {{Gavrilov, Yulian and Prestel, Andreas and Lindorff-Larsen, Kresten and Teilum, Kaare}},
  issn         = {{0961-8368}},
  keywords     = {{conformational dynamics; NMR spectroscopy; nuclear spin relaxation; protein stability}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{The Protein Society}},
  series       = {{Protein Science}},
  title        = {{Slow conformational changes in the rigid and highly stable chymotrypsin inhibitor 2}},
  url          = {{http://dx.doi.org/10.1002/pro.4604}},
  doi          = {{10.1002/pro.4604}},
  volume       = {{32}},
  year         = {{2023}},
}