Thermodynamic genetics of the folding of the B1 immunoglobulin-binding domain from streptococcal protein G
| Autor: | Karyn T. O'Neil, Ronald H. Hoess, William F. DeGrado, Daniel P. Raleigh |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Protein Denaturation
Protein Folding Circular dichroism Phage display Genetic Vectors Molecular Sequence Data Mutant Biochemistry Bacteriophage Bacterial Proteins Structural Biology Bacteriophages Amino Acid Sequence Molecular Biology Protein secondary structure Genetics Binding Sites Base Sequence biology Spectrum Analysis Streptococcus biology.organism_classification Fusion protein Mutagenesis G-domain Immunoglobulin G Thermodynamics Immunoglobulin binding |
| Zdroj: | Proteins: Structure, Function, and Genetics. 21:11-21 |
| ISSN: | 1097-0134 0887-3585 |
| DOI: | 10.1002/prot.340210103 |
| Popis: | A method has been developed to select proteins that are thermodynamically destabilized yet still folded and functional. The DNA encoding the B1 IgG-binding domain from Group G Streptococcus (Strp G) has been fused to gene III of bacteriophage M13. The resulting fusion protein is displayed on the surface of the phage thus enabling the phage to bind to IgG molecules. In addition, these phage exhibit a small plaque phenotype that is reversed by mutations that destabilize the Strp G domain. By selecting phage with large plaque morphology that retain their IgG-binding function, it is possible to identify mutants that are folded but destabilized compared with wild-type Strp G. Such mutants can be divided into three general categories: 1) those that disrupt packing of hydrophobic side chains in the protein interior; 2) those that destabilize secondary structure; and 3) those that alter specific hydrogen bonds involving amino acid side chains. A number of the mutants have been physically characterized by circular dichroism and nuclear magnetic resonance and have been shown to have structures similar to wild-type Strp G but stabilities that were decreased by 2-5 kcal/mol. |
| Databáze: | OpenAIRE |
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