A Whole Cell E. coli Display Platform for Artificial Metalloenzymes: Poly(phenylacetylene) Production with a Rhodium–Nitrobindin Metalloprotein

Abstract

Whole cell catalysis is, in many cases, a prerequisite for the cost-effective production of chemicals by biotechnological means. Synthetic metal catalysts for bioorthogonal reactions can be inactivated within cells due to abundant thiol derivatives. Here, a cell surface display-based whole cell biohybrid catalyst system (termed ArMt bugs) is reported as a generally applicable platform to unify cost-effective whole cell catalysis with biohybrid catalysis. An inactivated esterase autotransporter is employed to display the nitrobindin protein scaffold with a Rh catalyst on the E. coli surface. Stereoselective polymerization of phenylacetylene yielded a high turnover number (TON) (39 × 10 6 cell −1 ) for the ArMt bugs conversion platform.

Synthesis and Reactivity of an Early‐Transition‐Metal Alkynyl Cubane Mn4C4 Cluster

“…[29] Theinitially formed white suspension and slow color change to dark-brown may indicate the intermediacyo fa lkynyl manganese oligomers under catalytic conditions.T he reaction of Mn(hmds) 2 with phenylacetylene (2 equiv;or2 with 1equiv phenylacetylene) presumably gave rise to the formation of heterogeneous Mn 0 species upon deprotonation, coordination, and reductive elimination of 1,4-diphenylbutadiyne.W er ecently reported the efficient manganese-catalyzed hydrogenation of alkenes, alkynes,and imines under related mild conditions. Ther emaining substrate presumably underwent polymerization, which resulted in an orange solid with the characteristic broad 1 Hresonances at 5.5-8 ppm.…”

Unlocking the therapeutic potential of artificial metalloenzymes

“…3, a nitrobindin variant was fused with an inactivated esterase autotransporter (EstA) in order to be shuttled to microbial cell surfaces. 59) In this case, construction of the rhodium-based ArM was done through covalent linkage between Cys96 of the protein and a Rh(III)-maleimide complex. Subsequent studies then showed that phenylacetylene could be polymerized to PPA (also known as poly(phenylacetylene)) with high favorability to the trans isomer at a high turnover (39 # 10 6 per cell) on E. coli surfaces.…”

Synthesis and Reactivity of an Early‐Transition‐Metal Alkynyl Cubane Mn4C4 Cluster

“…Ther emaining substrate presumably underwent polymerization, which resulted in an orange solid with the characteristic broad 1 Hresonances at 5.5-8 ppm. [29] Theinitially formed white suspension and slow color change to dark-brown may indicate the intermediacyo fa lkynyl manganese oligomers under catalytic conditions.T he reaction of Mn(hmds) 2 with phenylacetylene (2 equiv;or2 with 1equiv phenylacetylene) presumably gave rise to the formation of heterogeneous Mn 0 species upon deprotonation, coordination, and reductive elimination of 1,4-diphenylbutadiyne.W er ecently reported the efficient manganese-catalyzed hydrogenation of alkenes, alkynes,and imines under related mild conditions. [10] Va rious Mn catalysts have recently been reported for the hydrogenation of carbonyl derivatives, [30,31] whereas olefin hydrogenation reactions are very rare.…”