SGD Paper Help



Bjornberg O, et al.  (2006) Mechanistic insight provided by glutaredoxin within a fusion to redox-sensitive yellow fluorescent protein. Biochemistry 45(7):2362-71

Abstract: Redox-sensitive yellow fluorescent protein (rxYFP) contains a dithiol disulfide pair that is thermodynamically suitable for monitoring intracellular glutathione redox potential. Glutaredoxin 1 (Grx1p) from yeast is known to catalyze the redox equilibrium between rxYFP and glutathione, and here, we have generated a fusion of the two proteins, rxYFP-Grx1p. In comparison to isolated subunits, intramolecular transfer of reducing equivalents made the fusion protein kinetically superior in reactions with glutathione. The rate of GSSG oxidation was thus improved by a factor of 3300. The reaction with GSSG most likely takes place entirely through a glutathionylated intermediate and not through transfer of an intramolecular disulfide bond. However, during oxidation by H(2)O(2), hydroxyethyl disulfide, or cystine, the glutaredoxin domain reacted first, followed by a rate-limiting (0.13 min(-)(1)) transfer of a disulfide bond to the other domain. Thus, reactivity toward other oxidants remains low, giving almost absolute glutathione specificity. We have further studied CPYC --> CPYS variants in the active site of Grx1p and found that the single Cys variant had elevated oxidoreductase activity separately and in the fusion. This could not be ascribed to the lack of an unproductive side reaction to glutaredoxin disulfide. Instead, slower alkylation kinetics with iodoacetamide indicates a better leaving-group capability of the remaining cysteine residue, which can explain the increased activity.

Status: Published Type: Journal Article PubMed ID: 16475825

Topics addressed in this paper

  • To find other papers on a gene and topic, click on the colored ball in the appropriate box.
  • displays other papers with information about that topic for that gene.
  • displays other papers in SGD that are associated with that topic.
    The topic is addressed in these papers but does not describe a specific gene or chromosomal feature.
  • To go to the Locus page for a gene, click on the gene name.
Topics Genes linked to topics
GRX1
Mutants/Phenotypes blue ball
Primary Literature blue ball
Protein Physical Properties blue ball
Protein Sequence Features blue ball
Strains/Constructs blue ball
Substrates/Ligands/Cofactors blue ball
Techniques and Reagents blue ball

Author Searches

To find contact information or other publications by the authors of this paper, follow these three steps:
  1. (1) Choose an author,
  2. (2) Choose a search parameter,
  3. (3) Click to implement