Vitamin D2 interacts with Human PrPc (90–231) and breaks PrPc oligomerization in vitro

Abstract

PrPsc, the pathogenic isoform of PrPc, can convert PrPc into PrPsc through direct interactions. PrPc oligomerization is a required processing step before PrPsc formation, and soluble oligomers appear to be the toxic species in amyloid-related disorders. In the current study, direct interactions between vitamin D2 and human recombinant PrPc (90–231) were observed by Biacore assay, and 3F4 antibody, specific for amino acid fragment 109–112 of PrPc, inhibited this interaction. An ELISA study using3F4 antibody showed that PrPc (101–130), corresponding sequence to human PrP, was affected by vitamin D2, supporting the results of Biacore studies and suggesting that the PrPc sequence around the 3F4 epitope was responsible for the interaction with vitamin D2. Furthermore, the effects of vitamin D2 on disruption of PrPc (90–231) oligomerization were elucidated by dot blot analysis and differential protease k susceptibilities. While many chemical compounds have been proposed as potential therapeutic agents for the treatment of scrapie, most of these are toxic. However, given the safety and blood brain barrier permeability of vitamin D2, we propose that vitamin D2 may be a suitable agent to target PrPc in the brain and therefore is a potential therapeutic candidate for prion disease.