Russo Fabio, Johnson Christopher J, Johnson Chad J, McKenzie Debbie, Aiken Judd M, Pedersen Joel A
Department of Soil Science and Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, USA.
J Gen Virol. 2009 Jan;90(Pt 1):275-80. doi: 10.1099/vir.0.003251-0.
Prions, the aetiological agents of transmissible spongiform encephalopathies, exhibit extreme resistance to degradation. Soil can retain prion infectivity in the environment for years. Reactive soil components may, however, contribute to the inactivation of prions in soil. Members of the birnessite family of manganese oxides (MnO(2)) rank among the strongest natural oxidants in soils. Here, we report the abiotic degradation of pathogenic prion protein (PrP(TSE)) by a synthetic analogue of naturally occurring birnessite minerals. Aqueous MnO(2) suspensions degraded the PrP(TSE) as evidenced by decreased immunoreactivity and diminished ability to seed protein misfolding cyclic amplification reactions. Birnessite-mediated PrP(TSE) degradation increased as a solution's pH decreased, consistent with the pH-dependence of the redox potential of MnO(2). Exposure to 5.6 mg MnO(2) ml(-1) (PrP(TSE) : MnO(2)=1 : 110) decreased PrP(TSE) levels by > or = 4 orders of magnitude. Manganese oxides may contribute to prion degradation in soil environments rich in these minerals.
朊病毒是传染性海绵状脑病的病原体，对降解具有极强的抵抗力。土壤可在环境中保持朊病毒感染力数年。然而，土壤中的活性成分可能有助于土壤中朊病毒的失活。锰氧化物（MnO₂）的水钠锰矿家族成员是土壤中最强的天然氧化剂之一。在此，我们报告了天然存在的水钠锰矿矿物的合成类似物对致病性朊病毒蛋白（PrP(TSE)）的非生物降解作用。MnO₂水悬浮液使PrP(TSE)降解，免疫反应性降低以及引发蛋白质错误折叠循环扩增反应的能力减弱证明了这一点。水钠锰矿介导的PrP(TSE)降解随着溶液pH值的降低而增加，这与MnO₂氧化还原电位的pH依赖性一致。暴露于5.6 mg MnO₂ ml⁻¹（PrP(TSE)∶MnO₂ = 1∶110）使PrP(TSE)水平降低了≥4个数量级。在富含这些矿物的土壤环境中，锰氧化物可能有助于朊病毒的降解。
