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Title: Artificial Metalloproteins Containing Co 4O 4Cubane Active Sites

Artificial metalloproteins (ArMs) containing Co 4O 4 cubane active sites were constructed via biotin-streptavidin technology. Stabilized by hydrogen bonds (H-bonds), terminal and cofacial Co III-OH 2 moieties are observed crystallographically in a series of immobilized cubane sites. Solution electrochemistry provided correlations of oxidation potential and pH. For variants containing Ser and Phe adjacent to the metallocofactor, 1e -/1H + chemistry predominates until pH 8, above which the oxidation becomes pH-independent. Installation of Tyr proximal to the Co 4O 4 active site provided a single H-bond to one of a set of cofacial Co III-OH 2 groups. With this variant, multi-e - /multi-H + chemistry is observed, along with a change in mechanism at pH 9.5 that is consistent with Tyr deprotonation. Finally, with structural similarities to both the oxygen-evolving complex of photosystem II (H-bonded Tyr) and to thin film water oxidation catalysts (Co 4O 4 core), these findings bridge synthetic and biological systems for water oxidation, highlighting the importance of secondary sphere interactions in mediating multi-e - /multi-H + reactivity.
Authors:
 [1] ;  [2] ; ORCiD logo [2] ;  [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [1]
  1. Univ. of California, Irvine, CA (United States). Dept. of Chemistry
  2. Univ. of California, Berkeley, CA (United States). Dept. of Physics
  3. Univ. of California, Berkeley, CA (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Chemical Science Division
Publication Date:
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 140; Journal Issue: 8; Journal ID: ISSN 0002-7863
Publisher:
American Chemical Society (ACS)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1433123

Olshansky, Lisa, Huerta-Lavorie, Raul, Nguyen, Andy I., Vallapurackal, Jaicy, Furst, Ariel, Tilley, T. Don, and Borovik, A. S.. Artificial Metalloproteins Containing Co4O4Cubane Active Sites. United States: N. p., Web. doi:10.1021/jacs.7b13052.
Olshansky, Lisa, Huerta-Lavorie, Raul, Nguyen, Andy I., Vallapurackal, Jaicy, Furst, Ariel, Tilley, T. Don, & Borovik, A. S.. Artificial Metalloproteins Containing Co4O4Cubane Active Sites. United States. doi:10.1021/jacs.7b13052.
Olshansky, Lisa, Huerta-Lavorie, Raul, Nguyen, Andy I., Vallapurackal, Jaicy, Furst, Ariel, Tilley, T. Don, and Borovik, A. S.. 2018. "Artificial Metalloproteins Containing Co4O4Cubane Active Sites". United States. doi:10.1021/jacs.7b13052.
@article{osti_1433123,
title = {Artificial Metalloproteins Containing Co4O4Cubane Active Sites},
author = {Olshansky, Lisa and Huerta-Lavorie, Raul and Nguyen, Andy I. and Vallapurackal, Jaicy and Furst, Ariel and Tilley, T. Don and Borovik, A. S.},
abstractNote = {Artificial metalloproteins (ArMs) containing Co4O4 cubane active sites were constructed via biotin-streptavidin technology. Stabilized by hydrogen bonds (H-bonds), terminal and cofacial Co III-OH2 moieties are observed crystallographically in a series of immobilized cubane sites. Solution electrochemistry provided correlations of oxidation potential and pH. For variants containing Ser and Phe adjacent to the metallocofactor, 1e-/1H+ chemistry predominates until pH 8, above which the oxidation becomes pH-independent. Installation of Tyr proximal to the Co4O4 active site provided a single H-bond to one of a set of cofacial CoIII-OH2 groups. With this variant, multi-e- /multi-H+ chemistry is observed, along with a change in mechanism at pH 9.5 that is consistent with Tyr deprotonation. Finally, with structural similarities to both the oxygen-evolving complex of photosystem II (H-bonded Tyr) and to thin film water oxidation catalysts (Co4O4 core), these findings bridge synthetic and biological systems for water oxidation, highlighting the importance of secondary sphere interactions in mediating multi-e- /multi-H+ reactivity.},
doi = {10.1021/jacs.7b13052},
journal = {Journal of the American Chemical Society},
number = 8,
volume = 140,
place = {United States},
year = {2018},
month = {2}
}