Journal article
Increased helix and protein stability through the introduction of a new tertiary hydrogen bond 1 1P.E. Wright
Journal of molecular biology, Vol.286(5), pp.1609-1619
03/1999
DOI: 10.1006/jmbi.1999.2574
Abstract
In an effort to quantify the importance of hydrogen bonding and α-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 ≃ 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 β-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.
Details
- Title: Subtitle
- Increased helix and protein stability through the introduction of a new tertiary hydrogen bond 1 1P.E. Wright
- Creators
- Ronald W Peterson - Texas A&M UniversityEric M Nicholson - Texas A&M UniversityRoopa Thapar - University of WashingtonRachel E Klevit - University of WashingtonJ.Martin Scholtz - Texas A&M University
- Resource Type
- Journal article
- Publication Details
- Journal of molecular biology, Vol.286(5), pp.1609-1619
- DOI
- 10.1006/jmbi.1999.2574
- ISSN
- 0022-2836
- eISSN
- 1089-8638
- Language
- English
- Date published
- 03/1999
- Academic Unit
- Chemistry; Research Administration; Biochemistry and Molecular Biology; Pharmaceutical Sciences and Experimental Therapeutics
- Record Identifier
- 9984288720402771
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