Understanding the role of negative charge in the scaffold of an artificial enzyme for CO 2 hydrogenation on catalysis.

Autor: Trevino RE; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA., Fuller JT 3rd; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA., Reid DJ; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA., Laureanti JA; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA.; Admiral Instruments, Tempe, AZ, 85281, USA., Ginovska B; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA., Linehan JC; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA., Shaw WJ; Pacific Northwest National Laboratory, 902 Battelle Boulevard, MSIN J7-10, PO Box 999, Richland, WA, 99352, USA. wendy.shaw@pnnl.gov.
Jazyk: angličtina
Zdroj: Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry [J Biol Inorg Chem] 2024 Sep; Vol. 29 (6), pp. 625-638. Date of Electronic Publication: 2024 Aug 29.
DOI: 10.1007/s00775-024-02070-0
Abstrakt: We have approached the construction of an artificial enzyme by employing a robust protein scaffold, lactococcal multidrug resistance regulator, LmrR, providing a structured secondary and outer coordination spheres around a molecular rhodium complex, [Rh I (P Et2 N gly P Et2 ) 2 ] - . Previously, we demonstrated a 2-3 fold increase in activity for one Rh-LmrR construct by introducing positive charge in the secondary coordination sphere. In this study, a series of variants was made through site-directed mutagenesis where the negative charge is located in the secondary sphere or outer coordination sphere, with additional variants made with increasingly negative charge in the outer coordination sphere while keeping a positive charge in the secondary sphere. Placing a negative charge in the secondary or outer coordination sphere demonstrates decreased activity by a factor of two compared to the wild-type Rh-LmrR. Interestingly, addition of positive charge in the secondary sphere, with the negatively charged outer coordination sphere restores activity. Vibrational and NMR spectroscopy suggest minimal changes to the electronic density at the rhodium center, regardless of inclusion of a negative or positive charge in the secondary sphere, suggesting another mechanism is impacting catalytic activity, explored in the discussion.
(© 2024. The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).)
Databáze: MEDLINE
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