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Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore.

Publication ,  Journal Article
Fry, HC; Lehmann, A; Saven, JG; DeGrado, WF; Therien, MJ
Published in: Journal of the American Chemical Society
March 2010

The first example of a computationally de novo designed protein that binds an emissive abiological chromophore is presented, in which a sophisticated level of cofactor discrimination is pre-engineered. This heterotetrameric, C(2)-symmetric bundle, A(His):B(Thr), uniquely binds (5,15-di[(4-carboxymethyleneoxy)phenyl]porphinato)zinc [(DPP)Zn] via histidine coordination and complementary noncovalent interactions. The A(2)B(2) heterotetrameric protein reflects ligand-directed elements of both positive and negative design, including hydrogen bonds to second-shell ligands. Experimental support for the appropriate formulation of [(DPP)Zn:A(His):B(Thr)](2) is provided by UV/visible and circular dichroism spectroscopies, size exclusion chromatography, and analytical ultracentrifugation. Time-resolved transient absorption and fluorescence spectroscopic data reveal classic excited-state singlet and triplet PZn photophysics for the A(His):B(Thr):(DPP)Zn protein (k(fluorescence) = 4 x 10(8) s(-1); tau(triplet) = 5 ms). The A(2)B(2) apoprotein has immeasurably low binding affinities for related [porphinato]metal chromophores that include a (DPP)Fe(III) cofactor and the zinc metal ion hemin derivative [(PPIX)Zn], underscoring the exquisite active-site binding discrimination realized in this computationally designed protein. Importantly, elements of design in the A(His):B(Thr) protein ensure that interactions within the tetra-alpha-helical bundle are such that only the heterotetramer is stable in solution; corresponding homomeric bundles present unfavorable ligand-binding environments and thus preclude protein structural rearrangements that could lead to binding of (porphinato)iron cofactors.

Duke Scholars

Published In

Journal of the American Chemical Society

DOI

EISSN

1520-5126

ISSN

0002-7863

Publication Date

March 2010

Volume

132

Issue

11

Start / End Page

3997 / 4005

Related Subject Headings

  • Zinc
  • Ultracentrifugation
  • Substrate Specificity
  • Proteins
  • Protein Structure, Secondary
  • Protein Structure, Quaternary
  • Protein Multimerization
  • Peptides
  • Molecular Sequence Data
  • Models, Molecular
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Fry, H. C., Lehmann, A., Saven, J. G., DeGrado, W. F., & Therien, M. J. (2010). Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore. Journal of the American Chemical Society, 132(11), 3997–4005. https://doi.org/10.1021/ja907407m
Fry, H Christopher, Andreas Lehmann, Jeffery G. Saven, William F. DeGrado, and Michael J. Therien. “Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore.Journal of the American Chemical Society 132, no. 11 (March 2010): 3997–4005. https://doi.org/10.1021/ja907407m.
Fry HC, Lehmann A, Saven JG, DeGrado WF, Therien MJ. Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore. Journal of the American Chemical Society. 2010 Mar;132(11):3997–4005.
Fry, H. Christopher, et al. “Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore.Journal of the American Chemical Society, vol. 132, no. 11, Mar. 2010, pp. 3997–4005. Epmc, doi:10.1021/ja907407m.
Fry HC, Lehmann A, Saven JG, DeGrado WF, Therien MJ. Computational design and elaboration of a de novo heterotetrameric alpha-helical protein that selectively binds an emissive abiological (porphinato)zinc chromophore. Journal of the American Chemical Society. 2010 Mar;132(11):3997–4005.
Journal cover image

Published In

Journal of the American Chemical Society

DOI

EISSN

1520-5126

ISSN

0002-7863

Publication Date

March 2010

Volume

132

Issue

11

Start / End Page

3997 / 4005

Related Subject Headings

  • Zinc
  • Ultracentrifugation
  • Substrate Specificity
  • Proteins
  • Protein Structure, Secondary
  • Protein Structure, Quaternary
  • Protein Multimerization
  • Peptides
  • Molecular Sequence Data
  • Models, Molecular