– Possesses thioredoxin activity. Has been shown to reduce insulin disulfide bonds. Also complements protein disulfide-isomerase deficiency in yeast. TXNDC5 Protein, Human, Recombinant (GST) is expressed in E. coli expression system with N-GST tag. The predicted molecular weight is 63.2 kDa and the accession number is Q8NBS9.