Artificial Cellulosome Complex from the Self-Assembly of NTANi Functionalized Polymeric Micelles and Cellulases.

Polymer-protein core-shell nanoparticles have been explored for enzyme immobilization. This work reports the development of functional polymeric micelles for immobilizing 6×His-tagged cellulases with controlled spatial orientation of enzymes, resulting in "artificial cellulosomes" for effective cellulose hydrolysis. Poly(styrene)-b-poly(styrene-alt-maleic anhydride) (PS-b-PSMA) was prepared through one-pot reversible addition-fragmentation chain-transfer (RAFT) polymerization and modified by nitrilotriacetic acid (NTA) to afford an amphiphilic block copolymer. The self-assembled polymer was mixed with NiSO4 solution to make NTANi functionalized micelles, which can successfully capture 6×His-tagged cellulases and form hierarchically structured core-shell nanoparticles with cellulases as the corona. Since the anchored enzymes are site-specifically oriented and in close proximity, a synergistic catalysis resulting in over two-fold activity enhancement was achieved.