If a protein is expressed in Origami 2 cells which contains mutation of Thioredoxin Reductase. How does the Theoredoxin that is tagged to the proteins helps in refolding when it also reduces disulfide bonds? This baffles me.
Why proteins is tagged with thioredoxin when thioredoxin reduces disulfide bonds?
Actually, origami 2 is a double redox mutant - both thioredoxin and glutathione reductase mutant. The proteins are not tagged with anything in this mutant, unless you choses so by adding another plasmid. Thioredoxin reductase mutant means that one of the redox systems is shut down which creates a more oxidative environment in the cell (the other one being glutaredoxin/glutathione), also in this case the lack of glutathione reductase means that GSSG is not that easily reduced to GSH, so that the redox ratio is in favor of GSSG (and thus the environment in the cell is less reduced). All in all, it helps in the formation of disulfide bonds in overexpressed proteins in the cytoplasm.
Thioredoxin tag is something different, it's a tag that helps in purification and generally enhances protein folding (fusion to a protein that folds properly and acts as a "chaperone" in proper folding of the attached protein). Another example is maltose binding protein as the fusion partner. See also:https://catalog.invitrogen.com/index.cfm...
blue tooth
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