Position‐dependent interactions between cysteine residues and the helix dipole
Abstract A protein model was developed for studying the interaction between cysteine residues and the helix dipole. Site‐directed mutagenesis was used to introduce cysteine residues at the N‐terminus of helix H in recombinant sperm whale myoglobin. Based on the difference in thiol pK a between folde...
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crwiley:10.1110/ps.0224203 2024-06-02T08:14:53+00:00 Position‐dependent interactions between cysteine residues and the helix dipole Miranda, JJ L. 2003 http://dx.doi.org/10.1110/ps.0224203 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1110%2Fps.0224203 https://onlinelibrary.wiley.com/doi/pdf/10.1110/ps.0224203 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Protein Science volume 12, issue 1, page 73-81 ISSN 0961-8368 1469-896X journal-article 2003 crwiley https://doi.org/10.1110/ps.0224203 2024-05-03T11:54:08Z Abstract A protein model was developed for studying the interaction between cysteine residues and the helix dipole. Site‐directed mutagenesis was used to introduce cysteine residues at the N‐terminus of helix H in recombinant sperm whale myoglobin. Based on the difference in thiol pK a between folded proteins and an unfolded peptide, the energy of interaction between the thiolate and the helix dipole was determined. Thiolates at the N1 and N2 positions of the helix were stabilized by 0.3 kcal/mole and 0.7 kcal/mole, respectively. A thiolate at the Ncap position was stabilized by 2.8 kcal/mole, and may involve a hydrogen bond. In context with other studies, an experimentally observed helix dipole effect may be defined in terms of two distinct components. A charge‐dipole component involves electrostatic interactions with peptide bond dipoles in the first two turns of the helix and affects residues at all positions of the terminus; a hydrogen bond component involves one or more backbone amide groups and is only possible at the capping position due to conformational restraints elsewhere. The nature and magnitude of the helix dipole effect is, therefore, position‐dependent. Results from this model system were used to interpret cysteine reactivity in rodent hemoglobins and the thioredoxin family. Article in Journal/Newspaper Sperm whale Wiley Online Library Protein Science 12 1 73 81 |
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Wiley Online Library |
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English |
description |
Abstract A protein model was developed for studying the interaction between cysteine residues and the helix dipole. Site‐directed mutagenesis was used to introduce cysteine residues at the N‐terminus of helix H in recombinant sperm whale myoglobin. Based on the difference in thiol pK a between folded proteins and an unfolded peptide, the energy of interaction between the thiolate and the helix dipole was determined. Thiolates at the N1 and N2 positions of the helix were stabilized by 0.3 kcal/mole and 0.7 kcal/mole, respectively. A thiolate at the Ncap position was stabilized by 2.8 kcal/mole, and may involve a hydrogen bond. In context with other studies, an experimentally observed helix dipole effect may be defined in terms of two distinct components. A charge‐dipole component involves electrostatic interactions with peptide bond dipoles in the first two turns of the helix and affects residues at all positions of the terminus; a hydrogen bond component involves one or more backbone amide groups and is only possible at the capping position due to conformational restraints elsewhere. The nature and magnitude of the helix dipole effect is, therefore, position‐dependent. Results from this model system were used to interpret cysteine reactivity in rodent hemoglobins and the thioredoxin family. |
format |
Article in Journal/Newspaper |
author |
Miranda, JJ L. |
spellingShingle |
Miranda, JJ L. Position‐dependent interactions between cysteine residues and the helix dipole |
author_facet |
Miranda, JJ L. |
author_sort |
Miranda, JJ L. |
title |
Position‐dependent interactions between cysteine residues and the helix dipole |
title_short |
Position‐dependent interactions between cysteine residues and the helix dipole |
title_full |
Position‐dependent interactions between cysteine residues and the helix dipole |
title_fullStr |
Position‐dependent interactions between cysteine residues and the helix dipole |
title_full_unstemmed |
Position‐dependent interactions between cysteine residues and the helix dipole |
title_sort |
position‐dependent interactions between cysteine residues and the helix dipole |
publisher |
Wiley |
publishDate |
2003 |
url |
http://dx.doi.org/10.1110/ps.0224203 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1110%2Fps.0224203 https://onlinelibrary.wiley.com/doi/pdf/10.1110/ps.0224203 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_source |
Protein Science volume 12, issue 1, page 73-81 ISSN 0961-8368 1469-896X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1110/ps.0224203 |
container_title |
Protein Science |
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12 |
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1 |
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73 |
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81 |
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1800738895874228224 |