posted on 2023-11-21, 01:03authored byGiovanni
B. Perin, Silvia Moreno, Yang Zhou, Markus Günther, Susanne Boye, Brigitte Voit, Maria I. Felisberti, Dietmar Appelhans
In recent years, there has been growing attention to
designing
synthetic protocells, capable of mimicking micrometric and multicompartmental
structures and highly complex physicochemical and biological processes
with spatiotemporal control. Controlling metabolism-like cascade reactions
in coacervate protocells is still challenging since signal transduction
has to be involved in sequential and parallelized actions mediated
by a pH change. Herein, we report the hierarchical construction of
membraneless and multicompartmentalized protocells composed of (i)
a cytosol-like scaffold based on complex coacervate droplets stable
under flow conditions, (ii) enzyme-active artificial organelles and
a substrate nanoreservoir capable of triggering a cascade reaction
between them in response to a pH increase, and (iii) a signal transduction
component based on the urease enzyme capable of the conversion of
an exogenous biological fuel (urea) into an endogenous signal (ammonia
and pH increase). Overall, this strategy allows a synergistic communication
between their components within the membraneless and multicompartment
protocells and, thus, metabolism-like enzymatic cascade reactions.
This signal communication is transmitted through a scaffold protocell
from an “inactive state” (nonfluorescent protocell)
to an “active state” (fluorescent protocell capable
of consuming stored metabolites).