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The Rate of Isomerisation of Peptidyl-proline Bonds as a Probe for Interactions in the Physiological Denatured State of Chymotrypsin Inhibitor 2

Tan, Yee-Joo; Oliveberg, Mikael LU ; Otzen, Daniel E and Fersht, Alan R (1997) In Journal of Molecular Biology 269(4). p.611-622
Abstract
There are four peptidyl-proline bonds in the 64-residue protein chymotrypsin inhibitor 2 (CI2), all of which are in the trans conformation in the native structure. The isomerisation of one or more of these peptidyl-proline bonds to the cis conformation in the denatured state gives rise to heterogeneity, leading to both fast and slow-folding species. The refolding of the fast-folding species, which has all trans peptidyl-proline bonds, is much faster than that of the slow-folding species, which have one or more cis peptidyl-proline bonds. In CI2, the slow-folding species can be classified into two groups by their rates of refolding, temperature-dependence, pH-dependence and [GdmCl]-dependence of the rate constants and the effect of... (More)
There are four peptidyl-proline bonds in the 64-residue protein chymotrypsin inhibitor 2 (CI2), all of which are in the trans conformation in the native structure. The isomerisation of one or more of these peptidyl-proline bonds to the cis conformation in the denatured state gives rise to heterogeneity, leading to both fast and slow-folding species. The refolding of the fast-folding species, which has all trans peptidyl-proline bonds, is much faster than that of the slow-folding species, which have one or more cis peptidyl-proline bonds. In CI2, the slow-folding species can be classified into two groups by their rates of refolding, temperature-dependence, pH-dependence and [GdmCl]-dependence of the rate constants and the effect of peptidyl-prolyl isomerase on the rate constants. The replacement of Pro6 by Ala removes one of the slow refolding phases, suggesting that the cis peptidyl-Pro6 conformation is solely responsible for one of the slow-folding species. Pro6 is located in a region of the protein where non-random interactions have been found in a series of N-terminal fragments of CI2 (residues 1 to 13, 1 to 25, 1 to 28 and 1 to 40). In addition, NMR studies on a mutant fragment, (1-40)T3A, have confirmed that this non-native interaction is associated with the bulky side-chain of Trp5. The atypical rate of cis to trans isomerisation of the peptidyl-Pro bond is indicative of the presence of a similar hydrophobic cluster in the physiological denatured state of intact CI2. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
protein, folding, cis-trans
in
Journal of Molecular Biology
volume
269
issue
4
pages
611 - 622
publisher
Elsevier
external identifiers
  • scopus:0031580205
ISSN
1089-8638
DOI
10.1006/jmbi.1997.1043
language
English
LU publication?
yes
id
0994f48c-943c-49de-ba71-ab1071724815 (old id 126248)
date added to LUP
2007-07-06 17:13:18
date last changed
2017-01-01 07:09:30
@article{0994f48c-943c-49de-ba71-ab1071724815,
  abstract     = {There are four peptidyl-proline bonds in the 64-residue protein chymotrypsin inhibitor 2 (CI2), all of which are in the trans conformation in the native structure. The isomerisation of one or more of these peptidyl-proline bonds to the cis conformation in the denatured state gives rise to heterogeneity, leading to both fast and slow-folding species. The refolding of the fast-folding species, which has all trans peptidyl-proline bonds, is much faster than that of the slow-folding species, which have one or more cis peptidyl-proline bonds. In CI2, the slow-folding species can be classified into two groups by their rates of refolding, temperature-dependence, pH-dependence and [GdmCl]-dependence of the rate constants and the effect of peptidyl-prolyl isomerase on the rate constants. The replacement of Pro6 by Ala removes one of the slow refolding phases, suggesting that the cis peptidyl-Pro6 conformation is solely responsible for one of the slow-folding species. Pro6 is located in a region of the protein where non-random interactions have been found in a series of N-terminal fragments of CI2 (residues 1 to 13, 1 to 25, 1 to 28 and 1 to 40). In addition, NMR studies on a mutant fragment, (1-40)T3A, have confirmed that this non-native interaction is associated with the bulky side-chain of Trp5. The atypical rate of cis to trans isomerisation of the peptidyl-Pro bond is indicative of the presence of a similar hydrophobic cluster in the physiological denatured state of intact CI2.},
  author       = {Tan, Yee-Joo and Oliveberg, Mikael and Otzen, Daniel E and Fersht, Alan R},
  issn         = {1089-8638},
  keyword      = {protein,folding,cis-trans},
  language     = {eng},
  number       = {4},
  pages        = {611--622},
  publisher    = {Elsevier},
  series       = {Journal of Molecular Biology},
  title        = {The Rate of Isomerisation of Peptidyl-proline Bonds as a Probe for Interactions in the Physiological Denatured State of Chymotrypsin Inhibitor 2},
  url          = {http://dx.doi.org/10.1006/jmbi.1997.1043},
  volume       = {269},
  year         = {1997},
}