Membraneless organelles (MLOs) are cellular compartments that, along with membrane-bound organelles, serve to regulate biochemical processes in a highly crowded and heterogeneous intracellular environment. Mounting evidence suggest that these membraneless condensates are formed via liquid-liquid phase separation, with intrinsically disordered proteins (IDPs) recognized as a major component that dictates their assembly and properties. While they are recognized as a functional core of many cellular functions, specific aspects regarding their dynamics, material state transitions, and physicochemical principles influencing their functions remain largely unexplored. Complex cellular environment makes it challenging to address these questions and necessitates development of in vitro reduction...[ Read more ]

Membraneless organelles (MLOs) are cellular compartments that, along with membrane-bound organelles, serve to regulate biochemical processes in a highly crowded and heterogeneous intracellular environment. Mounting evidence suggest that these membraneless condensates are formed via liquid-liquid phase separation, with intrinsically disordered proteins (IDPs) recognized as a major component that dictates their assembly and properties. While they are recognized as a functional core of many cellular functions, specific aspects regarding their dynamics, material state transitions, and physicochemical principles influencing their functions remain largely unexplored. Complex cellular environment makes it challenging to address these questions and necessitates development of in vitro reductionist approaches, that recapitulate basic biological features of MLOs in a minimalistic way, to gain deeper understanding of biological phase separation.

Here, we evaluated IDP-inspired polymer-oligopeptide hybrid (IPH) as a model artificial membraneless organelle (aMLO) and quantitatively explored some relevant physicochemical properties, such as internal dynamics, material properties, sequestration of molecules, and the capability to perform enzymatic reactions. Experimental evaluations revealed that this aMLO system exhibits desirable biomimetic characteristics and can recapitulate higher-order complexity of biological MLOs. In addition, this biomimetic system can incorporate both simple and multiplex biomimetic functionalities, overall rendering it useful as a study platform for further elucidation of unknown aspects of biological MLOs and as a synthetic system that can harness novel functionalities with application in synthetic biology and metabolic engineering.