Transmembrane Condensation in Albumin‐Loaded Giant Vesicles Induced by an Intrinsically Disordered Protein

ABSTRACT The interplay between biomolecular condensates and cellular membranes is central to understanding dynamic intracellular organization and membrane repair. Here, we present a minimal synthetic system to examine how membrane composition and curvature govern condensate–membrane interactions within this model platform. We demonstrate that the exposure of either lipid or polymer–lipid hybrid giant vesicles with encapsulated bovine serum albumin to a resilin‐inspired intrinsically disordered protein (IDP), which undergoes liquid–liquid phase separation, results in in situ formation of transmembrane condensates. This observation of cargo‐triggered condensation across giant vesicle membranes directly links encapsulated protein crowding to condensate nucleation and insertion. The condensation morphology was tunable by vesicle size and membrane elasticity where smaller vesicles and stiffer hybrid membranes favored transmembrane condensation, whereas larger or softer membranes promoted membrane wetting and deformation. Condensate formation locally reorganized lipids and facilitated leaflet coupling without compromising overall membrane integrity or cargo retention. This mechanistic understanding offers a unique opportunity to gain insight into the complex cell biological process of membrane repair using a minimal system.