  Multivalent associative proteins with strong complementary interactions play
a crucial role in phase separation of intracellular liquid condensates. We
study the internal dynamics of such "bond-network" condensates comprised of two
complementary proteins via scaling analysis and molecular dynamics. We find
that when stoichiometry is balanced, relaxation slows down dramatically due to
a scarcity of alternative partners following a bond break. This microscopic
slow-down strongly affects the bulk diffusivity, viscosity and mixing, which
provides a means to experimentally test our predictions.
