News and Publications

Research Efforts on the Cutting Edge of Chemistry and Biology

K.D. Janda, J.A. Ashley, T. Berg, O. Bruemmer, R. Carrera, S. Chen, A. Datta, C. Gao, D. Gravert, H. Han, C. Harwig, J. Hasserodt, T. Hoffman, D.M. Kubitz, M. Kubitz, C.-H. Lin, C.-H. Lo, S. Mao, B. Metz,* G.P. McElhaney, N. Reed, J. Shaw, A. Simeonov, M. Taylor, P. Wentworth, Jr., P. Wirsching, X. Zhao, B. Zhou

* Hoechst Marion Roussel, Inc., Cincinnati, OH

Our research efforts emphasize using organic synthesis to investigate important biological problems. We have focused our attention on 4 major areas: combinatorial chemistry, enzyme inhibition, immunopharmacotherapy, and catalytic antibodies.

COMBINATORIAL CHEMISTRY

The synthetic strategies used for high-throughput organic synthesis and construction of combinatorial libraries are driven by the need for optimal conversion, minimal side reactions, and simplified purification procedures. Soluble polymers or what has been termed liquid-phase supports have been used to address these needs. However, application of these polymers has been hampered by the availability of only a limited number of suitable supports and by the problem of polymer incompatibility with certain reagents.

We rationalized that greater success in this rapidly expanding field of polymer-supported chemistry could be achieved by tuning the solubility and stability of the support to a given set of reactions. To provide such tailor-made supports, we developed bifunctional free-radical initiators that facilitate the production of block copolymers from a diverse set of monomers (Fig. 1). This method provides new polymers with a wide range of solubility properties to match a particular set of reaction conditions.

ENZYME INHIBITION

Our efforts in enzyme inhibition have focused on 3 classes of enzymes: proteases, phosphodiesterases, and phosphotriesterases. Recently, we designed, synthesized, and investigated effective inhibitors of RNase A. One of these is a novel, pentavalent, distorted, square pyramidal rhenium chelate of adenosine (Fig. 2). We think this compound is a close transition-state mimic in the specific hydrolysis of phosphodiester bonds of RNA because it is a potent inhibitor of the reaction.

IMMUNOPHARMACOTHERAPY

Cocaine abuse is one of the most pressing health and sociologic problems confronting developed nations. In the United States, thousands of new users are added each day, and each year a large proportion of users die from overdose or other toxic influences. The effects on the unborn can be especially tragic. Persons addicted to cocaine represent the financial and social deterioration that this drug can inflict. Abuse not only is detrimental to the well-being of the user but also escalates to degrade the infrastructure of society. Of particular concern is the link between intravenous administration of cocaine and the spread of AIDS.

We have specifically delineated chemical, immunochemical, and immunologic data necessary for the implementation of immunopharmacologic protocols for the abatement of cocaine abuse. Our program encompasses synthesis of haptens and reagents, monoclonal antibodies that bind cocaine with high affinity and specificity, catalytic monoclonal antibodies that degrade cocaine, development of noncatalytic and catalytic vaccine designs, human monoclonal antibodies to cocaine derived from combinatorial libraries, and sophisticated animal behavioral models for testing all therapies.

CATALYTIC ANTIBODIES

Since the first reports of antibody catalysis, defining tenets for the generation of catalysts have been mimicry and incorporation of a reaction's transition-state stereoelectronics into hapten design. Success depends on accurate assumptions of mechanistic details, the extent to which the hapten is a model of the transition state, and how the immune system responds to the antigen. Although this approach has been successful for more than 50 chemical reactions, it has also been unsuccessful for some transformations. An example of the latter is the unassisted hydrolysis of an amide bond, a biochemical process of extreme importance. Using our direct selection for catalysis approach (Fig. 3), we devised a method that allows the selection of antibody catalysts for primary amide bond hydrolysis.

PUBLICATIONS

Berg, T., Vandersteen, A.M., Janda, K.D. High-throughput synthesis and direct screening for the discovery of novel hydrolytic metal complexes. Bioorg. Med. Chem. Lett. 8:1221, 1998.

Chen, S., Janda, K.D. Synthesis of prostaglandin E₂ methyl ester on a soluble polymer support for the construction of prostanoid libraries. J. Am. Chem. Soc. 119:8724, 1997.

Chen, S., Janda, K.D. Total synthesis of naturally occurring prostaglandin F₂ on a non-cross-linked polystyrene support. Tetrahedron Lett. 39:3943, 1998.

Gao, C., Lavey, B.J., Lo, C.-H.L., Datta, A., Wentworth, P., Jr., Janda, K.D. Direct selection for catalysis from combinatorial antibody libraries using a boronic acid probe: Primary amide bond hydrolysis. J. Am. Chem. Soc. 120:2211, 1998.

Gao, C., Lin, C.-H., Lo, C.-H.L., Mao, S., Wirsching, P., Lerner, R.A., Janda, K.D. Making chemistry selectable by linking it to infectivity. Proc. Natl. Acad. Sci. U.S.A. 94:11777, 1997.

Gravert, D.J., Janda, K.D. Bifunctional initiators for free radical polymerization of non-crosslinked block copolymers. Tetrahedron Lett. 39:1513, 1998.

Gravert, D.J., Janda, K.D. Organic reactions on soluble polymer supports as an alternative methodology for combinatorial solid-phase synthesis. In: Biotechnology International. Connor, T.H., Hairi, R.J. (Eds.). Universal Medical Press, San Francisco, 1997, p. 169.

Gravert, D.J., Janda, K.D. Soluble polyethylene glycol supports for liquid-phase combinatorial synthesis. Drugs Future 22:1147, 1997.

Gravert, D.J., Janda, K.D. Synthesis on soluble polymers: New reactions and the construction of small molecules. Curr. Opin. Chem. Biol. 1:107, 1998.

Han, H., Janda, K.D. Multipolymer-supported substrate and ligand approach to the Sharpless asymmetric dihydroxylation. Angew. Chem. Int. Ed. Engl. 36:1731, 1997.

Han, H., Yoon, J., Janda, K.D. An efficient asymmetric route to 2,3-diaminobutanoic acids. J. Org. Chem. 63:2045, 1998.

Han, H., Yoon, J., Janda, K.D. Investigations of azapeptides as mimetics of leu-enkephalin. Bioorg. Med. Chem. Lett. 8:117, 1998.

Hasserodt, J., Janda, K.D. Syntheses of octahydroquinoline-N-oxides: Haptens designed to elicit catalytic antibodies that control a terpenoid-like cascade cyclization. Tetrahedron 53:11237, 1997.

Hasserodt, J., Lerner, R.A., Janda, K.D. Formation of bridge-methylated decalins by antibody-catalyzed tandem cationic cyclization. J. Am. Chem. Soc. 119:5993, 1997.

Heine, A., Stura, E.A., Yli-Kauhaluoma, J.T., Gao, C., Deng, Q., Beno, B.R., Houk, K.N., Janda, K.D., Wilson, I.A. An antibody exo-Diels-Alderase inhibitor complex at 1.95 Å resolution. Science 279:1934, 1998.

Hori, M., Janda, K.D. A soluble polymer approach to the "fishing out" principle: Synthesis and purification of ß-amino alcohols. J. Org. Chem. 63:889, 1998.

Lin, C.-H., Hoffman, T.Z., Xie, Y., Wirsching, P., Janda, K.D. An antibody transesterase derived from reactive immunization that utilizes a wide variety of alcohol substrates. J. Chem. Soc. Chem. Commun. 1075, 1998.

Lin, C.-H., Hoffman, T.Z., Wirsching, P., Barbas, C.F. III, Janda, K.D., Lerner, R.A. On roads not taken in the evolution of protein catalysts: Antibody steroid isomerases that use an enamine mechanism. Proc. Natl. Acad. Sci. U.S.A. 94:11773, 1997.

Lo, C.-H.L., Wentworth, P., Jr., Jung, K.W., Yoon, J., Ashley, J.A., Janda, K.D. A reactive immunization strategy generates antibodies with high catalytic proficiencies. J. Am. Chem. Soc. 119:10251, 1997.

Wentworth, P., Jr., Janda, K.D. Catalytic antibodies. Curr. Opin. Chem. Biol. 2:138, 1998.

Wentworth, P., Jr., Janda, K.D. Synthesis of oxorhenium (V) and oxotechnetium (V) complexes as inhibitors of ribonucleases and for the generation of catalytic antibodies. Synlett 5:537, 1997.

Wentworth, P., Jr., Liu, Y., Wentworth, A.D., Fan, P., Foley, M.J., Janda, K.D. A bait and switch hapten strategy generates catalytic antibodies for phosphodiester hydrolysis. Proc. Natl. Acad. Sci. U.S.A. 95:5971, 1998.

Yli-Kauhaluoma, J.T., Janda, K.D. Unexpected 1,3-oxazolidine formation in the attempted oxidation of N-aryl-N-methyl substituted ß-amino alcohols using pyridinium dichromate. Tetrahedron Lett. 39:2269, 1998.

Zhao, X.-Y., Janda, K.D. Syntheses of alkylated malonates on a traceless linker derived soluble polymer support. Tetrahedron Lett. 38:5437, 1997.