Yung Pin Chen Research Professor of Biological Sciences Ph.D., 1986, Murdoch University, Western Australia 803-777-4736 chen@biol.sc.edu

Enzymology of Di/mono-oxygenases of Microbes and Marine Organisms; Degradation of Aromatic; Haloaromatic Hydrocarbons; Halogenating/dehalogenating Enzyme's Structures and Functions; Enzymatic Biocatalysts; Enzymology for Bioremediation and Phytoremediation

We have several significant discoveries: 1) The Notomastus labatus chloroperoxidase is the first haloperoxidase to be purified to homogeneity from marine polychaete. This chloroperoxidase appears to represent a new class of flavin-containing haloperoxidases (Chen et al., 1991); 2) The Amphitrite ornata dehaloperoxidase. This animal contains high levels of two very unusual dehalogenating enzymes, dehaloperoxidase (DHPl and DHP2). DHP1 has been purified. DHP1 is a heme-containing enzyme. This enzyme has broad spectrum of halogenated organic as substrate. No dehalogenase posses such properties. This is the first discovered a nove dehalogenase. (Chen et al., 1996); 3) A novel peroxide-dependent, dehalogenase-oxygenase has been detected in cell suspension culture of Spartina alterniflora and its roots. The plant enzyme shows very broad substrate specificity. It can break down halophenols with halogen groups in ortho, meta or para position. No dehalogenase passes such properties. Method for decomposing toxic organic pollutants. (U.S. Patent, 2000); 4) Halogenation of cephalexin with haloperoxidase from Rhathayibacter biopurensis is a method for producing a halogenated cephalexin and Rathayibacter Biopuresis produces Cephalosporin Haloperoxidase. (4 co-patents with Biopure Corporation, Boston, 1996-2000).

Dr Chen is further interested in isolating the novel bactreria that produce extracellular proteins and chemical compounds from marine organisms. It is shown that these proteins and chemical compounds are susceptible to Vancomycin resistant Enterococci, Methicillin and Vancomycin resistant Staphylococci, and multi-resistant Proteus. Further studies would be performed to clone the gene that is responsible for production of these antimicrobial compounds.

U.S. Patents and selected Publications:

Wong B., Shen Y.Q., Chen Y.P. (1999) Enzymatic production of cefaclor from cephalexin. U.S. Patent 5.939.299. August

Wong B., Shen Y.Q., Chen Y.P. (1998) Rathayibacter Biopuresis produces Cephalosporin Haloperoxidase. U.S. Patent 5.854.054. December

Wong B., Shen Y.Q., Chen Y.P. (1997) Chlorination of cephalexin with chloroperoxidase from Rathayibacter Biopuresis. U.S. Patent 5.695.951. December

Wong B., Shen Y.Q., Chen Y.P. (1996) Halogenation of cephalexin with haloperoxidase from Rathayibacter Biopuresis. U.S. Patent 5.589.354. December

Lovell, C. R., Eriksen, N., Lewitus, A. J., Chen. Y.P. (2000). Resistance of benthic microalgae to haloaromatic toxicity: Dechlorination and aromatic ring cleavage reactions catalyzed by the marine diatom Thalassiosira sp. J. Marine series. In press .

Lebioda, L., LaCount, M. W., Zhang, E., Chen, Y.P., Han, K., Whitton, M. M., Lincoln, D. E. and Woodin, S. A. (1999). Protein structure: An enzymatic globin from a marine worm. Nature 401,445.

Franzen, S., Roach, M.P., Chen, Y.P. Dyer,R.B., Woodruff,W.H., and Dawson,J.H. (1998). The unusual reactivities of Amphitrite ornata Dehaloperoxidase and Notomastus lobatus Chloroperoxidase do not arise from histidine imidazolate proximal heme iron ligand. J. Amer. Chem. Soc. 120:4658-4661.

Roach,M.P., Chen,Y.P., Woodin,S.A., Lincoln,D.E., Lovell, C.R., and Dawson,J.H. (1997). N. lobatus chloroperoxidase and A. ornata Dehaloperoxidase both contain Histidine as their proximal Heme iron ligand. J. Biol. Chem. 36: 2197-2202.

Chen, Y.P., Woodin, S.A., Lincoln, D.E., Lovell, C.R., (1996). An unusual dehalogenating peroxidase from the marine terebellid polychaete Amphitrite ornata. J. Biol. Chem. 271: 4609-4612.

Wang, S.P., Chen, Y.P.and Ely,B., (1995). A ferredoxin designated FdxP stimulates p-hydroxybenzoate hydroxylase activity in Caoulobacter crescentus. J. Bacteriol. 177: 2908-2911.

Chen, Y.P., and Lovell, C.R., (1994). Purification and properties of a homodimetric protocatechuate 4,5-dioxygenase from Rhizobium leguminosarum. Archives of Microbiology 161: 191-195.

Chen, Y.P., Lopez-de-Victoria, G., and Lovell, C.R., (1993). Utilization of aromatic compounds as carbon and energy sources during growth and N2-fixation by free-living nitrogen fixing bacteria. Archives of Microbiology 159: 207-212.

Chen, Y.P., Lincoln, D. E., Woodin, S. A., and Lovell, C.R., (1991). Purification and properties of a unique flavin-containing chloroperoxidase from the capitellid polycheate Notomastus lobatus. J. Biol. Chem. 266: 23909-23915.