Position-dependent interactions between cysteine residues and the helix dipole
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 recom-binant sperm whale myoglobin. Based on the difference in thiol pKa between folded protein...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.527.9235 2023-05-15T18:26:47+02:00 Position-dependent interactions between cysteine residues and the helix dipole Jj L. Miranda The Pennsylvania State University CiteSeerX Archives 2002 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.9235 http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.9235 http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf Helix dipole helix capping hemoglobin thioredoxin myoglobin cysteine thiolate hydrogen text 2002 ftciteseerx 2016-01-08T10:26:32Z 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 recom-binant sperm whale myoglobin. Based on the difference in thiol pKa 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. Text Sperm whale Unknown |
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topic |
Helix dipole helix capping hemoglobin thioredoxin myoglobin cysteine thiolate hydrogen |
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Helix dipole helix capping hemoglobin thioredoxin myoglobin cysteine thiolate hydrogen Jj L. Miranda Position-dependent interactions between cysteine residues and the helix dipole |
topic_facet |
Helix dipole helix capping hemoglobin thioredoxin myoglobin cysteine thiolate hydrogen |
description |
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 recom-binant sperm whale myoglobin. Based on the difference in thiol pKa 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Jj L. Miranda |
author_facet |
Jj L. Miranda |
author_sort |
Jj L. Miranda |
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 |
publishDate |
2002 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.9235 http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf |
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Sperm whale |
genre_facet |
Sperm whale |
op_source |
http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.527.9235 http://mirandalab.ucsf.edu/publications_assets/miranda_ps_2003.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766208751780495360 |