|Title||The conserved active site tryptophan of thioredoxin has no effect on its redox properties.|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Authors||Roos, G., P. Geerlings, and J. Messens|
|Date Published||2010 Jan|
|Type of Article||redox|
|Keywords||Catalytic Domain, Conserved Sequence, Cysteine, Models, Molecular, Mutation, Oxidation-Reduction, Protein Stability, Staphylococcus aureus, Thioredoxins, Tryptophan|
In Staphylococcus aureus thioredoxin (Trx) it has been shown that mutation of the conserved active site tryptophan residue (Trp28) has a large effect on the protein stability, on the pKa of the nucleophilic cysteine and on the redox potential. Since these effects can either be due to the partially unfolding of the Trp28Ala mutant or to the absence of the indole side chain of Trp28 as possible interaction partner for the active site cysteines, the origin of the experimentally observed effects is not known and is beyond experimental approach. With theoretical pKa and density functional theory reactivity analysis on model systems where Trp28 has been replaced by an alanine within the structural environment of Trx it is shown that Trp28 does not affect the redox parameters of Trx. As such, the experimentally observed redox effects of the Trx W28A mutant might be due to structural changes induced by partial unfolding.
|Alternate Journal||Protein Sci.|
|PubMed Central ID||PMC2817855|
The conserved active site tryptophan of thioredoxin has no effect on its redox properties.