Binding of Dissolved Organic Matter to RNA and Protection from Nuclease-Mediated Degradation

Abstract

The persistence of RNA in environmental systems is an important parameter for emerging applications, including ecological surveys, wastewater-based epidemiology, and RNA interference biopesticides. RNA persistence is controlled by its rate of biodegradation, particularly by extracellular enzymes, although the specific factors determining this rate have not been characterized. Due to prior work suggesting that nucleic acids−specifically DNA−interact with dissolved organic matter (DOM), we hypothesized that DOM may bind RNA and impede its biodegradation in natural systems. We first adapted a technique previously used to assess RNA-protein binding to differentiate RNA that is bound at all sites by DOM from RNA that is unbound or partially bound by DOM. Results from this technique suggested that humic acids bound RNA more extensively than fulvic acids. At concentrations of 8−10 mg C /L, humic acids were also found to be more effective than fulvic acids at suppressing enzymatic degradation of RNA. In surface water and soil extract containing DOM, RNA degradation was suppressed by 39−46% relative to pH-adjusted controls. Due to the ability of DOM to both bind and suppress the enzymatic degradation of RNA, RNA biodegradation may be slowed in environmental systems with high DOM concentrations, which may increase its persistence.

Urban wastewater contains a functional human antibody repertoire of mucosal origin

“…Physical, chemical, and microorganism-driven protease activities will affect the degree to which a protein will stay in its native state. Analogous to what has been demonstrated with DNA and RNA, proteins are likely to be partially protected by being encapsulated in complex dissolved organic matter and extracellular polymeric substances (50)(51)(52). Post-translational modifications including glycosylation could also contribute to protection from (photo)chemical and enzymatic degradation.…”