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Thermodynamic effects of replacements of pro residues in helix interiors of maltose-binding protein
- Source :
- Proteins: Structure, Function, and Genetics. 53:863-871
- Publication Year :
- 2003
- Publisher :
- Wiley, 2003.
-
Abstract
- Introduction of Pro residues into helix interiors results in protein destabilization. It is currently unclear if the converse substitution (i.e., replacement of Pro residues that naturally occur in helix interiors would be stabilizing). Maltose-binding protein is a large 370-amino acid protein that contains 21 Pro residues. Of these, three nonconserved residues (P48, P133, and P159) occur at helix interiors. Each of the residues was replaced with Ala and Ser. Stabilities were characterized by differential scanning calorimetry (DSC) as a function of pH and by isothermal urea denaturation studies as a function of temperature. The P48S and P48A mutants were found to be marginally more stable than the wild-type protein. In the pH range of 5-9, there is an average increase in T(m) values of P48A and P48S of 0.4 degrees C and 0.2 degrees C, respectively, relative to the wild-type protein. The other mutants are less stable than the wild type. Analysis of the effects of such Pro substitutions in MBP and in three other proteins studied to date suggests that substitutions are more likely to be stabilizing if the carbonyl group i-3 or i-4 to the mutation site is not hydrogen bonded in the wild-type protein.
- Subjects :
- Protein Denaturation
Protein Folding
Genotype
Proline
Mutant
Calorimetry
medicine.disease_cause
Biochemistry
Maltose-Binding Proteins
Protein Structure, Secondary
Maltose-binding protein
Differential scanning calorimetry
Structural Biology
medicine
Urea
Molecular Biology
Mutation
Binding Sites
biology
Hydrogen bond
Chemistry
Temperature
Wild type
Hydrogen-Ion Concentration
Protein Structure, Tertiary
Crystallography
Amino Acid Substitution
Protein destabilization
Helix
biology.protein
Thermodynamics
Carrier Proteins
Subjects
Details
- ISSN :
- 10970134 and 08873585
- Volume :
- 53
- Database :
- OpenAIRE
- Journal :
- Proteins: Structure, Function, and Genetics
- Accession number :
- edsair.doi.dedup.....213ddd07af0817a332d69038114bbfc6