SCIENCE & TECHNOLOGY: Prions—Still a Mystery!
Posted 01 February 2011 | By
In 1975, when Lewis Thomas, physician, scientist and medical writer, was asked to make a list of the Seven Wonders of the Modern World, he chose scrapie disease, now known to be caused by a proteinaceous infectious particle (prion), as number four.1 To quote Thomas, "The scrapie agent seems the strangest thing in all biology." His reason was that the disease can propagate from a few infectious units to billions in just one year despite the absence of DNA or RNA. Without DNA or RNA, there was a serious question regarding the mode with which the agent replicated and survived. Prions, which even in 1975 showed evidence of being all protein, appeared to violate the central dogma of molecular biology: genetic information flows from nucleic acids to proteins.2