Fig. 1: Illustration of the static and transient vacuolation induced in protein-based coacervates.
From: Static and transient vacuolation in protein-based coacervates induced by charged amino acids
In route (i), supercharged unfolded polypeptide bearing 72 positive charges (K72) is engineered and complexed with negatively charged GFP30 into inert coacervate microdroplets via LLPS. The following introduction of charged AAs (L-aspartic acid, glutamic acid or lysine) induces charge access that leads to the formation of static vacuoles in K72/GFP30 droplets. In route (ii), a biological enzyme, L-asparaginase (ASP), is first fused to K72 via genetic engineering and then condensed with GFP30, producing enzymatically active coacervates. The addition of the substrate, L-asparagine, in situ generates L-aspartic acid that initiates transient vacuolation in ASP-K72/GFP30 droplets. The transient vacuoles can be initiated for many cycles via the repeated introduction of L-asparagine.
