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Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase.

Publication ,  Journal Article
Kilpatrick, L; Rajagopalan, KV; Hilton, J; Bastian, NR; Stiefel, EI; Pilato, RS; Spiro, TG
Published in: Biochemistry
March 7, 1995

Resonance Raman spectra are compared for Rhodobacter sphaeroides dimethyl sulfoxide reductase, an enzyme containing a molybdopterin cofactor, and two model compounds, I and II, which have pterin and quinoxaline, respectively, attached to a Cp2Mo[IV]-dithiolene chelate [Cp = cyclopentadienyl]. The effect of 34S incorporation was also determined. Several bands in the 200-500 cm-1 region show remarkably similar patterns of frequencies and isotope shifts between protein and models: a band at 351 cm-1 shifts 6-8 cm-1, and bands at lower and higher frequencies show smaller shifts upon 34S substitution. A normal coordinate analysis on II indicates the 351 cm-1 mode to be the symmetric Mo-S[dithiolene] stretch and the remaining low-frequency modes to contain contributions from deformations of the quinoxaline ring as well as from Mo-S stretching. The similarity in the low-frequency spectra between the model compounds and the enzyme strongly supports a dithiolene chelate as the mode of Mo-pterin interaction in the cofactor. Resonance enhancement of both high- and low-frequency quinoxaline or pterin modes is observed for both model compounds, implicating the heterocyclic rings as part of the electronic system involved in the Mo-dithiolene charge transfer transitions. RR spectra of 6-methylpterin and biopterin are reported and used to identify the pterin and quinoxaline high-frequency bands in the model compound spectra. The dithiolene C = C stretch is tentatively assigned to bands at 1506 cm-1 in I and 1515 cm-1 in II.(ABSTRACT TRUNCATED AT 250 WORDS)

Duke Scholars

Published In

Biochemistry

DOI

ISSN

0006-2960

Publication Date

March 7, 1995

Volume

34

Issue

9

Start / End Page

3032 / 3039

Location

United States

Related Subject Headings

  • Spectrum Analysis, Raman
  • Spectrophotometry
  • Rhodobacter sphaeroides
  • Pterins
  • Pteridines
  • Protein Denaturation
  • Oxidoreductases
  • Molybdenum Cofactors
  • Molybdenum
  • Molecular Structure
 

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Kilpatrick, L., Rajagopalan, K. V., Hilton, J., Bastian, N. R., Stiefel, E. I., Pilato, R. S., & Spiro, T. G. (1995). Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase. Biochemistry, 34(9), 3032–3039. https://doi.org/10.1021/bi00009a034
Kilpatrick, L., K. V. Rajagopalan, J. Hilton, N. R. Bastian, E. I. Stiefel, R. S. Pilato, and T. G. Spiro. “Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase.Biochemistry 34, no. 9 (March 7, 1995): 3032–39. https://doi.org/10.1021/bi00009a034.
Kilpatrick L, Rajagopalan KV, Hilton J, Bastian NR, Stiefel EI, Pilato RS, et al. Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase. Biochemistry. 1995 Mar 7;34(9):3032–9.
Kilpatrick, L., et al. “Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase.Biochemistry, vol. 34, no. 9, Mar. 1995, pp. 3032–39. Pubmed, doi:10.1021/bi00009a034.
Kilpatrick L, Rajagopalan KV, Hilton J, Bastian NR, Stiefel EI, Pilato RS, Spiro TG. Resonance Raman spectroscopic characterization of the molybdopterin active site of DMSO reductase. Biochemistry. 1995 Mar 7;34(9):3032–3039.
Journal cover image

Published In

Biochemistry

DOI

ISSN

0006-2960

Publication Date

March 7, 1995

Volume

34

Issue

9

Start / End Page

3032 / 3039

Location

United States

Related Subject Headings

  • Spectrum Analysis, Raman
  • Spectrophotometry
  • Rhodobacter sphaeroides
  • Pterins
  • Pteridines
  • Protein Denaturation
  • Oxidoreductases
  • Molybdenum Cofactors
  • Molybdenum
  • Molecular Structure