Peroxide Activation for Electrophilic Reactivity by the Binuclear Non-heme Iron Enzyme AurF
Binuclear non-heme iron enzymes activate O 2 for diverse chemistries that include oxygenation of organic substrates and hydrogen atom abstraction. This process often involves the formation of peroxo-bridged biferric intermediates, only some of which can perform electrophilic reactions. To elucidate the geometric and electronic structural requirements to activate peroxo reactivity, the active peroxo intermediate in 4-aminobenzoate N-oxygenase (AurF) has been characterized spectroscopically and computationally. A magnetic circular dichroism study of reduced AurF shows that its electronic and geometric structures are poised to react rapidly with O 2. Nuclear resonance vibrational spectroscopic definition of the peroxo intermediate formed in this reaction shows that the active intermediate has a protonated peroxo bridge. Density functional theory computations on the structure established here show that the protonation activates peroxide for electrophilic/single-electron-transfer reactivity. As a result, this activation of peroxide by protonation is likely also relevant to the reactive peroxo intermediates in other binuclear non-heme iron enzymes.
- Authors:
-
[1]
; [2]
; [3]
;
[3]
; [3]
; [3]
; [3]
; [4]
; [5]
; [5]
; [6]
; [6]
; [2]
; [2]
; [7]
- Stanford Univ., Stanford, CA (United States); KAIST, Daejeon (Republic of Korea)
- Pennsylvania State Univ., University Park, PA (United States)
- Stanford Univ., Stanford, CA (United States)
- SPring-8/JASRO, Hyogo (Japan)
- Kyoto Univ., Osaka (Japan)
- Argonne National Lab. (ANL), Lemont, IL (United States)
- Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Publication Date:
- Grant/Contract Number:
- AC02-76SF00515; CHE-1058931; MCB1404866; 24221005; GM40392; AC02-06CH11357
- Type:
- Accepted Manuscript
- Journal Name:
- Journal of the American Chemical Society
- Additional Journal Information:
- Journal Volume: 139; Journal Issue: 20; Journal ID: ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)
- Research Org:
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH); National Science Foundation (NSF); Japan Society for the Promotion of Science (JSPS) - KAKENHI
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; O2 activation; diiron site; peroxo intermediate; nuclear resonance vibrational spectroscopy; O2; activation
- OSTI Identifier:
- 1369431
- Alternate Identifier(s):
- OSTI ID: 1377396