News and Publications

Bioorganic and Synthetic Chemistry

C.-H. Wong, G.-J. Shen, P.S. Sears, A.K. Datta, P. Alper, M. Burkart, S.-J. Chung, W. Greenberg, M. Hendrix, F. Huang, S.-C. Hung, C. Huwe, J. Jablonowski, K. Koeller, T. Lampe, V.-D. Le, T. Lee, C.-C. Lin, J. Liu, G. McGarvey, T. Machajewski, D. Manning, F. Moris-Varas, M. Mitchell, I. Ollmann, C. Rosenbohm, S. Priestley, A. Schleyer, O. Seitz, M. Shelton, E. Simanek, M. Smith, S. Takayama, V. Vassilev, K. Witte, R. Wischnat, T. Wittmann, X.-S. Ye, J. Yun, Z. Zhang

Our research programs are directed toward (1) development of new chemoenzymatic strategies for the synthesis of biologically active compounds and chiral intermediates, (2) development of mechanism-based inhibitors of enzymes and receptors, and (3) investigation of reaction mechanisms.

CHEMOENZYMATIC ORGANIC SYNTHESIS

Our work on chemoenzymatic organic synthesis includes the design of substrates and the exploitation of native, recombinant, and rationally modified enzymes for organic synthesis. Our synthetic strategy emphasizes a combination of chemical and enzymatic methods, with particular focus on the use of enzymes for stereocontrolled processes. In the past year, we developed several new synthetic methods. These include the use of Selectfluor in the synthesis of 2-fluoroglycosides, the use of aldolases in novel aldol addition reactions, enzymatic resolution of chiral amines with removable protecting groups, synthesis of novel ß-hydroxy-/alpha/-amino acids by using threonine aldolases, and chemoenzymatic synthesis of glycopeptides and glycoproteins (Fig. 1) by using engineered subtilisins and recombinant glycosyltransferases in combination with the solid-phase chemoenzymatic method developed in this laboratory.

DEVELOPMENT OF ENZYME AND RECEPTOR INHIBITORS

Our goals in the area of enzyme and receptor inhibitors are to develop new strategies and discover new therapeutic agents that have high selectivity. Current strategies are based on combinatorial and rational approaches; the latter involve the design and synthesis of structure- and mechanism-based inhibitors of enzymes or receptors associated with metabolic disorders or diseases. Targets for investigation include carbohydrates and carbohydrate receptors, such as anticancer antigens (Fig. 2), selectins in cell adhesion, and bacterial RNA involved in protein synthesis; retroviral proteases; and the enzymes involved in the processing of glycoproteins, the inflammatory reaction, the glycosidic cleavage of DNA and RNA, and the biosynthesis of leukotrienes.

In addition to the new iminocyclitols and derivatives developed as inhibitors of glycosidases and glycosyltransferases, we have developed new tight-binding inhibitors of HIV protease and its drug-resistant mutant enzymes (Fig. 3). Finally, we have designed and synthesized novel sialyl Lewis X mimetics that inhibit selectins with activity greater than that of sialyl Lewis X (Fig. 4) and are considered potential candidates for drug development.

PUBLICATIONS

Alper, P., Hendrix, M., Wong, C.-H. Probing the specificity of aminoglycoside-RNA interactions with designed synthetic analogs. J. Am. Chem. Soc. 120:1965, 1998.

Burkart, M.D., Hung, S.-C., Zhang, Z., Wong, C.-H. A new method for the synthesis of fluoro-carbohydrates and glycosides using Selectfluor™. J. Am. Chem. Soc. 119:11743, 1997.

Hogg, J.H., Ollmann, I.R., Wetterhold, A., Andberg, M.B., Haeggstrom, J., Samuelsson, B., Wong, C.-H. Probing the activities and mechanisms of leukotriene A4 hydrolase using synthetic inhibitors and site-directed mutagenesis. Chem. Eur. J., in press.

Ikeda, T., Kajimoto, T., Kondo, H., Wong, C.-H. Design and synthesis of an /alpha/-mannosyl terpenoid as a selective inhibitor of P-selectin. Bioorg. Med. Chem. Lett. 7:2485, 1997.

Kamitakahara, H., Suzuki, T., Nishigori, N., Suzuki, Y., Kanie, O., Wong, C.-H. Lyso GM₃ ganglioside-poly-l-glutamic acid conjugate as picomolar inhibitor of influenza hemagglutinin. Angew. Chem. Int. Ed. 37:1524, 1998.

Kanebo, M., Kanie, O., Kajimoto, T., Wong, C.-H. Toward a transition state analog inhibitor of N-acetylglucosaminyl transferase V. Bioorg. Med. Chem. Lett. 7:2809, 1997.

Kanie, Y., Kirsch, A., Kanie, O., Wong, C.-H. Enzymatic assay of galactosyltransferase by capillary electrophoresis. Anal. Biochem., in press.

Kimura, T., Vassilev, V.P., Shen, G.-J., Wong, C.-H. Enzymatic synthesis of ß-hydroxy-/alpha/-amino acids based on d- and l-threonine aldolases. J. Am. Chem. Soc. 119:1173, 1997.

Koketsu, M., Nitoda, T., Sugino, H., Juneja, L.R., Kim, M., Yamamoto, T., Abe, N., Kajimoto, T., Wong, C.-H. Synthesis of a novel sialic acid derivative (sialylphospholipid) as an antirotaviral agent. J. Med. Chem. 40:3332, 1997.

Lampe, T., Weitz-Schmidt, G., Wong, C.-H. Parallel synthesis of sialyl Lewis X mimetics on solid phase, a library approach toward fucopeptides. Angew. Chem. Int. Ed. 37:1707, 1998.

Lee, T., Laco, G.S., Torbett, B.E., Fox, H.S., Lerner, D.L., Elder, J.H., Wong, C.-H. Analysis of the S₃ and S₃´ subsite specificity of FIV protease: Development of a broad-based protease inhibitor efficacious against FIV, SIV and HIV in vitro and ex vivo. Proc. Natl. Acad. Sci. U.S.A. 95:939, 1998.

Martin, R., Witte, K.L., Wong, C.-H. The synthesis and enzymatic incorporation of sialic acid derivatives for use as tools to study the structure, activity and inhibition of glycoproteins and other glycoconjugates. Bioorg. Med. Chem., in press.

Miura, T., Kajimoto, T., Jimbo, M., Yamagishi, K., Inokuchi, J.-C., Wong, C.-H. Synthesis and evaluation of morpholino- and pyrrolidinosphingolipids as inhibitors of glycosylceramide synthase. Bioorg. Med. Chem., in press.

Sears, P., Lin, C.-C., Hung, S.-C., Takayama, S., Witte, K.L., Alper, P.B., Wong, C.-H. Mechanism-based inhibition of carbohydrate-mediated biological recognitions. Chem. Commun. 11:1161, 1998.

Sears, P., Witte, K., Wong, C.-H. The effect of counterion, water concentration, and stirring on the stability of subtilisin BPN´ in organic solvents. J. Mol. Catalysis, in press.

Sears, P., Wong, C.-H. Enzyme action in glycoprotein processing. Cell. Mol. Life Sci. 54:223, 1998.

Seitz, O., Wong, C.-H. Chemo-enzymatic solution and solid phase synthesis of an O-sialyl-Lewis X-octapeptide of the mucin domain of MAdCAM-1. J. Am. Chem. Soc. 119:8766, 1997.

Simanek, E., McGarvey, G.J., Wong, C.-H. Selectin-carbohydrate interaction: From natural ligands to designed mimics. Chem. Rev. 98:838, 1998.

Takayama, S., Lee, S.T., Hung, S.-C., Wong, C.-H. Designing acylating reagents for enzymatic resolution of amines. Angew. Chem. Int. Ed., in press.

Takayama, S., McGarvey, G.J., Wong, C.-H. Enzymes in organic synthesis: Recent development in aldol reactions and glycosylations. Chem. Soc. Rev. 26:407, 1997.

Tsai, C.Y., Park, W.K.C., Weitz-Schmidt, G., Ernst, B., Wong, C.-H. Synthesis of sialyl Lewis X mimetics using the Ugi four-component reaction. Bioorg. Med. Chem. Lett., in press.

Vassilev, V.P., Simanek, E.E., Wood, M.R., Wong, C.-H. Enzymatic synthesis of a chiral gelator with remarkably low molecular weight. Chem. Commun., in press.

Witte, K., Seitz, O., Wong, C.-H. Solution and solid-phase synthesis of N-protected peptide esters of the benzyl type as substrates for subtilisin-catalyzed glycopeptide coupling. J. Am. Chem. Soc. 120:1979, 1998.

Wittmann, V., Takayama, S., Kong, K.W., Weitz-Schmidt, G., Wong, C.-H. Ligand recognition by E- and P-selectin: Chemoenzymatic synthesis and inhibitory activity of bivalent sialyl Lewis X derivatives and sialyl Lewis X carboxylic acids. J. Org. Chem., in press.

Wong, C.-H., Hendrix, M., Manning, D.D. A library approach to the discovery of small molecules that recognize RNA: Use of a 1,3-hydroxyamine motif as core. J. Am. Chem. Soc., in press.

Wong, C.-H., Hendrix, M., Priestley, E.S., Greenberg, W.A. Specificity of aminoglycoside antibiotics for the ribosomal decoding region A-site RNA. Chem. Biol. 5:397, 1998.

Wong, C.-H., Ye, X.-S., Zhang, Z. Assembly of oligosaccharide libraries using a designed building block and an efficient orthogonal protection-deprotection strategy. J. Am. Chem. Soc., in press.