Solid-Phase Synthesis of Megamolecules

This paper presents a solid-phase strategy to effi-ciently assemble multi-protein scaffolds — known as megamolecules — without the need for protect-ing groups and with precisely-defined nanoscale architectures. The megamolecules are assembled through sequential reactions of linkers that present irreversible inhibitors for enzymes and fusion pro-teins containing the enzyme domains. Here, a fu-sion protein containing an N-terminal cutinase and a C-terminal SnapTag domain react with an ethyl p-nitrophenyl phosphonate (pNPP) or a chloro-pyrimidine (CP) group, respectively, to give cova-lent products. By starting with resin beads that are functionalized with BG, a series of reactions lead to linear, branched and dendritic structures that are released from the solid support by addition of TEV protease and that have sizes of up to approximately 25 nm.