Biomimetic Construction of Abiotic Membranes Through Acylation of Cationic Diamino Acids

Abstract

[Abstract] Compartmentalization is a defining feature of living systems and a cornerstone of bottom-up synthetic biology. Although phospholipids dominate modern biological membranes, their de novo synthesis in the laboratory remains chemically demanding and offers limited headgroup diversity, thereby constraining the functional scope of artificial membranes. Here, we describe a simple and modular strategy to access choline-mimetic abiotic phospholipid analogs (APAs) that recapitulate key structural and functional features of natural phospholipids. Diamino acids serve as minimal scaffolds onto which a trimethylammonium (TMA) headgroup is introduced in a single step through carboxylate conjugation with Girard's Reagent T (GRT), generating a permanent choline-like cation. Subsequent N-acylation under mild aqueous conditions with prebiotically relevant thioesters yields diacylated amino GRT (DAAG) amphiphiles with a classical phospholipid topology. These APAs spontaneously self-assemble into well-defined vesicular structures and allow systematic tuning of headgroup charge and composition. Our approach facilitates access to chemically versatile, TMA-functionalized membranes that expand the toolkit for constructing functional artificial membranes in synthetic biology, protocell research, and molecular delivery.