A 3D mesoscale simulation framework for the vesicular artificial cell life cycle was built with an extended Dissipative Particle Dynamics approach (mprDPD). This highly simplified life-cycle contains metabolic turnover of amphiphilic components, constructed from precursors that need to be assimilated from the surrounding medium, consistent with a homeostatic metabolizing cell. Here we utilize this framework to investigate how the genetic determination of component molecule properties can result in emergent evolutionary optimization of the artificial cell, via modulation of its life-cycle. We chose to focus on the genetic determination of amphiphile metabolism, as a common point where the three core cell functionalities meet. This genetic influence on amphiphile metabolic synthesis can be simplified and rephrased in terms of an inheritance law for autocatalytic amphiphile synthesis.
Recall that the simplest basic mechanism that we proposed for the vesicular cell life-cycle is
where activated amphiphiles (or lipids L*) in an aqueous medium (W) autocatalytic-ally convert dilute natively renewable resource precursors (P) to produce more amphiphiles (L). The amphiphiles self-assemble because of their intermolecular interactions with oneanother and with the aqueous medium (including hydrophilic and hydrophobic interactions). A genetic amphiphile such as catalipids or an amphiphilic PNA will have intermolecular interaction properties depending on its molecular sequence [1].
We model this by giving each L particle (independently of their activation) an individual value for the local (minimum free energy) membrane curvature, that is inherited with variation from catalyst to product amphiphile. Additionally, we have explored the patch formation (surface segregation) of different amphiphiles via a dependency of the intermolecular attraction on the natural curvature (e.g. maximal attraction for similar intrinsic curvature). This promotes homogeneity of daughter cell amphiphile populations, potentially faster cell division, and promotes the accuracy of inheritance. Here we deal with the simpler case of non specific attractive interactions between amphiphiles.