The phase equilibria of intrinsically disordered proteins are exquisitely sensitive to changes in solution conditions and this can be used to investigate the driving forces of phase separation in vitro as well as the biological roles of phase transitions in live cells. Here we investigate how using D₂O as co-solvent in an aqueous buffer changes the phase equilibrium of a fragment of the activation domain of the androgen receptor, a transcription factor that plays a role in the development of the male phenotype and is a therapeutic target for castration resistant prostate cancer. We show how replacing even small fractions of H₂O with D₂O increases the propensity of this fragment to undergo liquid–liquid phase separation, likely reflecting a stabilization of the hydrophobic interactions that drive condensation. Our results indicate that it is necessary to take this effect into consideration when studying phase separation phenomena with biophysical methods that require using D₂O as a co-solvent. In addition, they suggest that additions of D₂O may be used to enhance phase separation phenomena in cells, facilitating their observation.

中文翻译：

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少量重水会增加雄激素受体激活域片段的相分离倾向

内在无序蛋白质的相平衡对溶液条件的变化非常敏感，这可用于研究体外相分离的驱动力以及活细胞中相变的生物学作用。在这里，我们研究了在水性缓冲液中使用 D ₂ O 作为共溶剂如何改变雄激素受体激活域片段的相平衡，雄激素受体是一种在男性表型发育中发挥作用的转录因子，是一种治疗药物。去势抵抗性前列腺癌的靶点。我们展示了如何用D _{2代替即使是一小部分的 H 2 O}O 增加了该片段进行液 - 液相分离的倾向，可能反映了驱动冷凝的疏水相互作用的稳定。_{我们的结果表明，在使用需要使用 D 2} O 作为助溶剂的生物物理方法研究相分离现象时，有必要考虑这种影响。此外，他们建议添加 D ₂ O 可用于增强细胞中的相分离现象，便于观察。