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What enzyme cleaves disulfide bonds?

What enzyme cleaves disulfide bonds?

Thioredoxin and glutaredoxin catalyze reduction of disulfide bonds in the cytosol and nucleus (1, 5).

What do disulfide bonds stabilize?

Disulfide bonds stabilize protein structure by organizing and destabilizing the denatured protein relative to the native structure.

How are disulfide bonds broken?

Disulfide bonds can be broken by addition of reducing agents. The most common agents for this purpose are ß-mercaptoethanol (BME) or dithiothritol (DTT).

How do disulfide bonds stabilize globular proteins?

Classical theory suggests that disulfide bonds stabilize proteins by reducing the entropy of the denatured state. Experimental thermodynamic evidence is examined from two sources: (1) the disruption of naturally occurring disulfides, and (2) the insertion of novel disulfides.

What is the role of disulfide bonds in DsbC?

DsbC (Disulfide bond C) is a prokaryotic disulfide bond isomerase. The formation of native disulfide bonds play an important role in the proper folding of proteins and stabilize tertiary structures of the protein.

How does the reduced cysteine in DsbC work?

In addition to this, DsbC also shows chaperone activity. The reduced cysteine on DsbC performs a nucleophilic attack on the target non-native disulfide bond, to form an unstable disulfide bond between DsbC and the protein. Another thiolate group in the protein then attacks this unstable bond.

What is the structure of DsbC from E coli?

The structure of DsbC from E. coli as reported by McCarthy et al. shows the cysteines in the oxidized state. In wild-type cells, both cysteines are in the reduced state. Synthesis of proteins with multiple disulfide bonds is challenging due to formation of non-native disulfide bonds. This usually leads to insoluble, inactive proteins.

How does DsbC and DsbG contribute to protein folding?

DsbC and DsbG facilitate the proper folding of the protein by breaking non-native disulfide bonds. In addition to this, DsbC also shows chaperone activity. The reduced cysteine on DsbC performs a nucleophilic attack on the target non-native disulfide bond, to form an unstable disulfide bond between DsbC and the protein.