Liquid–liquid phase separation rescues the conformational stability of a DNA hairpin from pressure–stress

Abstract

Aqueous two-phase systems are able to rescue the conformational stability of DNA hairpins under harsh environmental conditions.

Alteration of the Conformational Dynamics of a DNA Hairpin by α‐Synuclein in the Presence of Aqueous Two‐Phase Systems

“…From these and literature data for the DNA-HPs ystem in neat buffer solution (Figures 3 and 4i nR ef. [25]), it is evident that the open conformation (unfolded state) becomes more populated with increasing pressureinthe absence [25] and presence of a-Syn (Figure 2 in neat buffer solution( DV = À27 cm 3 mol À1 ) [25] can be calculated for unfolding of the DNA-HP.…”

“…They are relatedt oc onformations with differents eparations, R,o ft he two attached dyes and thus different FRET efficiencies, E,a sE = R 6 0 /(R 6 0 + R 6 ): The Fçrster radius, that is, the distance at which 50 %o ft he excited donor molecules will be deactivated, is R 0 = 6.5 nm for the fluorophores used (Atto 550 and Atto 647 N). [25,32] The two peaks are located at E % 0.3 and E % 0.9, respectively.T he peak at the lower FRET efficiency represents the open state, where the donora nd acceptor distance is maximum, and the higherF RET efficiency represents the closed conformation of the DNA-HP, where donor and acceptor are at ap roximal distance. At ambient temperature and pressure conditions, the ratio of the open to closed state is approximately 0.81.…”

“…[22][23][24] Due to the lack of ap hysical barrier,s uch as al ipid membrane, these liquid condensates are able to exchange their components rapidlyw ith the surroundingm edium. The effect of liquid-liquid phase separation (LLPS) as observed in artificial aqueoust wo-phase systems (ATPS) on the conformational dynamics of biomolecules, including DNA,i sh ardly explored, however, [25] and has therefore been included in this study.…”

“…Recently,i th as been shown that HHP application on the DNA-HP in neat buffer solution gradually populates the low-FRET distribution species( E % 0.3), which is due to the unfolding of the DNA-HP. [25,32,33] Figures 1D and Figure 2d isplay the pressuree ffecto nt he conformational states of the DNA-HP in the presence of different concentrations of a-Syn (the smFRET histograms are shown in Figure S1). From these and literature data for the DNA-HPs ystem in neat buffer solution (Figures 3 and 4i nR ef.…”

“…LLPS is known to significantly modulate an array of physiological processes, including protein dynamics, folding, aggregation,a nd activity,t on ame af ew. [23,25,36,37] Here, we used an artificial ATPS composed of ad extran (11wt%)a nd PEG (11wt%)m ixture to mimic intracellular LLPS conditions. The advantage of this system is the absence of ap ressure effect on the stability of the ATPS itself.…”