Short peptides from Late Embryogenesis Abundant (LEA) proteins tune liquid–liquid phase separation and prevent aggregation

Short peptides derived from Late Embryogenesis Abundant (LEA) proteins are critically important because they appear to exert their protective functions through liquid-liquid phase separation (LLPS) in vivo. Excitingly, confocal fluorescence microscopy revealed that green fluorescent protein (GFP) exhibited a heterogeneous intracellular distribution in Escherichia coli cells co-expressing LEA peptides. Guided by this observation, we conducted in vitro LLPS assays and found that the LEA-II and LEA-K peptides attenuated segregative LLPS while enhancing solution stability in the associative LLPS mode. These data support our hypothesis that LEA peptides function as molecular shields that suppress protein aggregation, thereby improving heterologous protein expression.