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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
5
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pubmed:dateCreated |
1999-4-27
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pubmed:abstractText |
In an effort to quantify the importance of hydrogen bonding and alpha-helix formation to protein stability, a capping box motif was introduced into the small phosphocarrier protein HPr. Previous studies had confirmed that Ser46, at the N-cap position of the short helix-B in HPr, serves as an N-cap in solution. Thus, only a single-site mutation was required to produce a canonical S-X-X-E capping box: Lys49 at the N3 position was substituted with a glutamic acid residue. Thermal and chemical denaturation studies on the resulting K49E HPr show that the designed variant is approximately 2 kcal mol-1 more stable than the wild-type protein. However, NMR studies indicate that the side-chain of Glu49 does not participate in the expected capping H-bond interaction, but instead forms a new tertiary H-bond that links helix-B to the four-stranded beta-sheet of HPr. Here, we demonstrate that a strategy in which new non-native H-bonds are introduced can generate proteins with increased stability. We discuss why the original capping box design failed, and compare the energetic consequences of the new tertiary side-chain to main-chain H-bond with a local (helix-capping) side-chain to main-chain H-bond on the protein's global stability.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0022-2836
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pubmed:author |
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pubmed:copyrightInfo |
Copyright 1999 Academic Press.
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pubmed:issnType |
Print
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pubmed:day |
12
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pubmed:volume |
286
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1609-19
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:10064718-Amino Acid Substitution,
pubmed-meshheading:10064718-Bacterial Proteins,
pubmed-meshheading:10064718-Escherichia coli,
pubmed-meshheading:10064718-Hydrogen Bonding,
pubmed-meshheading:10064718-Kinetics,
pubmed-meshheading:10064718-Models, Molecular,
pubmed-meshheading:10064718-Mutation,
pubmed-meshheading:10064718-Nuclear Magnetic Resonance, Biomolecular,
pubmed-meshheading:10064718-Phosphoenolpyruvate Sugar Phosphotransferase System,
pubmed-meshheading:10064718-Protein Conformation,
pubmed-meshheading:10064718-Protein Denaturation,
pubmed-meshheading:10064718-Protein Engineering,
pubmed-meshheading:10064718-Protein Folding,
pubmed-meshheading:10064718-Protein Structure, Secondary,
pubmed-meshheading:10064718-Protons,
pubmed-meshheading:10064718-Serine,
pubmed-meshheading:10064718-Solvents,
pubmed-meshheading:10064718-Temperature,
pubmed-meshheading:10064718-Thermodynamics,
pubmed-meshheading:10064718-Urea
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pubmed:year |
1999
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pubmed:articleTitle |
Increased helix and protein stability through the introduction of a new tertiary hydrogen bond.
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pubmed:affiliation |
College Station, Texas A&M University, TX, 77843-1114, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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