Biochem/physiol Actions NN-DNJ is a glucosidase inhibitor that acts as a pharmacologic chaperone. NN-DNJ also acts synergistically with proteostasis modulators such as celastrol and MG132 to stabilize mutant proteins in properly folded states. NN-DNJ stabilizes various proteins against misfolding, increasing proper trafficking from the endoplasmic reticulum. There is potential use in studying diseases marked by misfolded proteins and has shown antiviral activity.