Arnold, F.H.

J. Am. Chem. Soc. 2019, 141, 19585-19588, 10.1021/jacs.9b11608

Transition-metal catalysis is a powerful tool for the construction of chemical bonds. Here we show that Pseudomonas savastanoi ethylene-forming enzyme, a non-heme iron enzyme, can catalyze olefin aziridination and nitrene C−H insertion, and that these activities can be improved by directed evolution. The nonheme iron center allows for facile modification of the primary coordination sphere by addition of metalcoordinating molecules, enabling control over enzyme activity and selectivity using small molecules.

Tiller, J.C.

ChemCatChem 2016, 8, 593-599, 10.1002/cctc.201501083

The Sharpless dihydroxylation of styrene with the artificial metalloenzyme osmate‐laccase‐poly(2‐methyloxazoline) was investigated to find reaction conditions that allow this unique catalyst to reveal its full potential. After changing the co‐oxidizing agent to tert‐butyl hydroperoxide and optimizing the osmate/enzyme ratio, the turnover frequency and the turnover number could be increased by an order of magnitude, showing that the catalyst can compete with classical organometallic catalysts. Varying the metal in the active center showed that osmate is by far the most active catalytic center, but the reaction can also be realized with permanganate and iron(II) salts.

Tiller, J.C.

ChemBioChem 2015, 16, 83-90, 10.1002/cbic.201402339

Count Os in: We report organosoluble artificial metalloenzymes, generated from poly(2‐methyl‐oxazoline) enzyme conjugates and osmate as a promising new catalytic system for the dihydroxylation of alkenes in organic media.

Imanaka, T.

FEBS Lett. 1995, 375, 273-276, 10.1016/0014-5793(95)01224-3

In order to engineer a new type of catalytic antibody, we attempt to use a monoclonal antibody L chain as a host protein for a porphyrin. TCPP (meso‐tetrakis(4‐carboxyphenyl)porphyine) was chemically synthesized and Balb/c mice were immunized using TCPP as a hapten. Two hybridoma cells (03‐1, 13‐1), that produce monoclonal antibody against TCPP, were obtained. Genes for both H and L chains of monoclonal antibodies were cloned, sequenced and overexpressed using E. coli as a host. ELISA and fluorescence quenching method show that the independent antibody L chains from both Mab03‐1 and Mab13‐1 have specific interaction with TCPP. Furthermore, the recombinant antibody L chain from Mab13‐1 exhibits much higher peroxidase activity than TCPP Fe(III) alone. The enzyme activity was detectable with pyrogallol and ABTS (2,2‐azinobis‐3‐ethylbenzthiazolin‐6‐sulfonic acid) but not with catechol. This new catalytic antibody was extremely thermostable. Optimum temperature of the peroxidase reaction by the complex of 13‐1L chain and TCPP Fe(III) was 90°C, while that the TCPP Fe(III) alone was 60°C.