Published on Web 05/29/2008
Artificial Metalloenzyme for Enantioselective Sulfoxidation
Based on Vanadyl-Loaded Streptavidin
Anca Pordea,† Marc Creus,† Jaroslaw Panek,‡ Carole Duboc,§ De´borah Mathis,†
Marjana Novic,‡ and Thomas R. Ward*,†
Institute of Chemistry, UniVersity of Neuchaˆtel, AVenue BelleVaux 51, CP 158,
2009 Neuchaˆtel, Switzerland, Laboratory of Chemometrics, National Institute of Chemistry,
HajdrihoVa 19, SI-1001 Ljubljana, SloVenia, and De´partement de Chimie Mole´culaire UMR 5250,
ICMG FR 2607, CNRS, UniVersite´ Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
Received March 7, 2008; E-mail: thomas.ward@unibas.ch
Abstract: Nature’s catalysts are specifically evolved to carry out efficient and selective reactions. Recent
developments in biotechnology have allowed the rapid optimization of existing enzymes for enantioselective
processes. However, the ex nihilo creation of catalytic activity from a noncatalytic protein scaffold remains
very challenging. Herein, we describe the creation of an artificial enzyme upon incorporation of a vanadyl
ion into the biotin-binding pocket of streptavidin, a protein devoid of catalytic activity. The resulting artificial
metalloenzyme catalyzes the enantioselective oxidation of prochiral sulfides with good enantioselectivities
both for dialkyl and alkyl-aryl substrates (up to 93% enantiomeric excess). Electron paragmagnetic resonance
spectroscopy, chemical modification, and mutagenesis studies suggest that the vanadyl ion is located within
the biotin-binding pocket and interacts only via second coordination sphere contacts with streptavidin.
Introduction
this concept, and inspired by the use of vanadium in biocatalytic
oxidations,12 we selected the vanadyl-catalyzed sulfoxidation
The affinity of biotin for streptavidin ranks among the
strongest noncovalent interactions found in nature (Ka ∼1013
M-1).1–3 To achieve such unrivaled affinities, both hydrogen-
bonding and hydrophobic interactions are combined to provide
an exquisitely tailored biotin binding site.4–7 This deep cavity
can bind, albeit with significantly reduced affinity, a variety of
ligands, including HABA, ANS, different oligopeptides, etc.8–11
In the context of artificial metalloenzymes, we reasoned that a
catalytically active small polar coordination compound may
interact with the biotin-binding residues via hydrogen bonds.
In addition, the presence of hydrophobic residues may favor
substrate accumulation within the cavity, resulting in increased
turnover rates for the catalyzed reaction. To test the validity of
of prochiral substrates (Scheme 1).
In recent years, there has been an increasing interest in the
creation of artificial metalloenzymes for enantioselective ca-
talysis. With this goal in mind, covalent, supramolecular as well
as dative anchoring strategies have been used to ensure the
localization of a catalytically active moiety within a chiral
macromolecule (protein or DNA) scaffold. The enantioselective
reactions implemented thus far include ester hydrolysis,13 dihy-
droxylation,14 epoxidation,15,16 sulfoxidation,17–21 hydrogenation,22–30
(12) Hemrika, W.; Renirie, R.; Dekker, H. L.; Barnett, P.; Wever, R. Proc.
Natl. Acad. Sci. U.S.A. 1997, 94, 2145.
(13) Davies, R. R.; Distefano, M. D. J. Am. Chem. Soc. 1997, 119, 11643.
(14) Kokubo, T.; Sugimoto, T.; Uchida, T.; Tanimoto, S.; Okano, M.
J. Chem. Soc., Chem. Commun. 1983, 769.
† University of Neuchaˆtel.
‡ National Institute of Chemistry.
(15) Okrasa, K.; Kazlauskas, R. J. Chem.sEur. J. 2006, 12, 1587.
(16) Fernandez-Gacio, A.; Codina, A.; Fastrez, J.; Riant, O.; Soumillion,
P. ChemBioChem 2006, 7, 1013.
§ Universite´ Joseph Fourier.
(1) Wilchek, M.; Bayer, E. A. Methods in Enzymology, Vol. 184: AVidin-
Biotin Technology; Academic Press: San Diego, CA, 1990.
(2) Kuntz, I. D.; Chen, K.; Sharp, K. A.; Kollman, P. A. Proc. Natl. Acad.
Sci. U.S.A. 1999, 96, 9997.
(17) van de Velde, F.; Ko¨nemann, L.; van Rantwijk, F.; Sheldon, R. A.
Chem. Commun. 1998, 1891.
(18) Ohashi, M.; Koshiyama, T.; Ueno, T.; Yanase, M.; Fujii, H.; Watanabe,
Y. Angew. Chem., Int. Ed. 2003, 42, 1005.
(3) Rao, J.; Lahiri, J.; Isaacs, L.; Weis, R. M.; Whitesides, G. M. Science
1998, 280, 708.
(19) Ueno, T.; Koshiyama, T.; Ohashi, M.; Kondo, K.; Kono, M.; Suzuki,
A.; Yamane, T.; Watanabe, Y. J. Am. Chem. Soc. 2005, 127, 6556.
(20) Carey, J. R.; Ma, S. K.; Pfister, T. D.; Garner, D. K.; Kim, H. K.;
Abramite, J. A.; Wang, Z.; Guo, Z.; Lu, Y. J. Am. Chem. Soc. 2004,
126, 10812.
(4) Weber, P. C.; Ohlendorf, D. H.; Wendoloski, J. J.; Salemme, F. R.
Science 1989, 243, 85.
(5) DeChancie, J.; Houk, K. N. J. Am. Chem. Soc. 2007, 129, 5419.
(6) Livnah, O.; Bayer, E. A.; Wilchek, M.; Sussman, J. L. Proc. Natl.
Acad. Sci. U.S.A. 1993, 90, 5076.
(21) Mahammed, A.; Gross, Z. J. Am. Chem. Soc. 2005, 127, 2883.
(22) Wilson, M. E.; Whitesides, G. M. J. Am. Chem. Soc. 1978, 100, 306.
(23) Lin, C.-C.; Lin, C.-W.; Chan, A. S. C. Tetrahedron: Asymmetry 1999,
10, 1887.
(7) Hyre, D. E.; Le Trong, I.; Merritt, E. A.; Eccleston, J. F.; Green, N. M.;
Stenkamp, R. E.; Stayton, P. S. Protein Sci. 2006, 15, 459.
(8) Schmidt, T. G. M.; Skerra, A. Protein Eng. 1993, 6, 109.
(9) Weber, P. C.; Wendoloski, J. J.; Pantoliano, M. W.; Salemme, F. R.
J. Am. Chem. Soc. 1992, 114, 3197.
(24) Collot, J.; Gradinaru, J.; Humbert, N.; Skander, M.; Zocchi, A.; Ward,
T. R. J. Am. Chem. Soc. 2003, 125, 9030.
(10) Green, N. M. AdV. Protein Chem. 1975, 29, 85.
(11) Dixon, R. W.; Radmer, R. J.; Kuhn, B.; Kollman, P. A.; Yang, J.;
Raposo, C.; Wilcox, C. S.; Klumb, L. A.; Stayton, P. S.; Behnke, C.;
Le Trong, I.; Stenkamp, R. J. Org. Chem. 2002, 67, 1827.
(25) Collot, J.; Humbert, N.; Skander, M.; Klein, G.; Ward, T. R. J.
Organomet. Chem. 2004, 689, 4868.
(26) Klein, G.; Humbert, N.; Gradinaru, J.; Ivanova, A.; Gilardoni, F.;
Rusbandi, U. E.; Ward, T. R. Angew. Chem., Int. Ed. 2005, 44, 7764.
9
10.1021/ja8017219 CCC: $40.75
2008 American Chemical Society
J. AM. CHEM. SOC. 2008, 130, 8085–8088 8085