Editing Prion (section)

=== Degradation resistance in nature ===
Overwhelming evidence shows that prions resist degradation and persist in the environment for years, and [[protease]]s do not degrade them. Experimental evidence shows that ''unbound'' prions degrade over time, while soil-bound prions remain at stable or increasing levels, suggesting that prions likely accumulate in the environment.<ref>{{cite journal | vauthors = Zabel M, Ortega A | title = The Ecology of Prions | journal = Microbiology and Molecular Biology Reviews | volume = 81 | issue = 3 | date = September 2017 | pmid = 28566466 | pmc = 5584314 | doi = 10.1128/MMBR.00001-17 }}</ref><ref>{{cite journal | vauthors = Kuznetsova A, Cullingham C, McKenzie D, Aiken JM | title = Soil humic acids degrade CWD prions and reduce infectivity | journal = PLOS Pathogens | volume = 14 | issue = 11 | pages = e1007414 | date = November 2018 | pmid = 30496301 | pmc = 6264147 | doi = 10.1371/journal.ppat.1007414 | doi-access = free }}</ref> One 2015 study by US scientists found that repeated drying and wetting may render soil bound prions less infectious, although this was dependent on the soil type they were bound to.<ref>{{cite journal | vauthors = Yuan Q, Eckland T, Telling G, Bartz J, Bartelt-Hunt S | title = Mitigation of prion infectivity and conversion capacity by a simulated natural process--repeated cycles of drying and wetting | journal = PLOS Pathogens | volume = 11 | issue = 2 | pages = e1004638 | date = February 2015 | pmid = 25665187 | pmc = 4335458 | doi = 10.1371/journal.ppat.1004638 | doi-access = free }}</ref>