Microsoft word - document

Using Haloperoxidase Enzymes to Develop Inter-
disciplinary Student Work Focussed on Sustainable
Exploitation of Marine Natural Resources

Les Jervis (Biological Science, Plymouth) and Simon Belt (Faculty
of Science, Plymouth)

Summary
The project wil build on work with biology students. It wil also bring research
on the applications of haloperoxidase enzymes into the undergraduate chemistry curriculum in such a way that chemistry undergraduate students Use enzymes as catalysts to facilitate the synthesis of organo-halogens, avoiding hazardous chemical syntheses (green chemistry). Use modern analytical techniques (GC and GC/MS) to monitor the formation of product and confirm their identity. Use haloperoxidases to develop safe biodegradative routes for azo dye wastes by using seaweed beds as biofilters for dye factory effluent. Work jointly with marine biology undergraduates to develop a model system for studying the sustainable production of a bioactive organo- halogen by ‘green chemistry’ using haloperoxidase catalysts. Assist in the development of the project via undergraduate research Interim report

Summary
The project wil build on work with biology students. It wil also bring research on the applications of haloperoxidase enzymes into the undergraduate chemistry curriculum in such a way that chemistry undergraduate students • Use enzymes as catalysts to facilitate the synthesis of organo- halogens, avoiding hazardous chemical syntheses (green chemistry). • Use modern analytical techniques (GC and GC/MS) to monitor the formation of product and confirm their identity. • Use haloperoxidases to develop safe biodegradative routes for azo dye wastes by using seaweed beds as biofilters for dye factory effluent. • Work jointly with marine biology undergraduates to develop a model system for studying the sustainable production of a bioactive organo- halogen by ‘green chemistry’ using haloperoxidase catalysts. • Assist in the development of the project via undergraduate research
The Project
Degradation of the global environment is an issue that concerns everyone and is of particular interest to the majority of science students. One factor identified often as being of importance in environmental degradation is the production, and release into the environment, of organo-halogens such as polychlorinated biphenyls (PCBs) and chlorofluorocarbons (CFCs). The former are resistant to biodegradation and accumulate in body fat deposits. This is of considerable concern in the case of mammals as the PCBs are released into milk during fat mobilisation in lactating females. The CFCs are implicated as a major factor in damage to the ozone layer leading to increased penetration of UV light with potential y serious consequences for genetic damage. Whilst considerable effort has been devoted to studying the damaging consequences of man-made organo-halogens, recognition of the range and scale of production and release of natural organo-halogens from biological or geological sources has been slow to develop. Recent estimates suggest that volcanoes release of the order of 11 mil ion tons of hydrogen fluoride plus 3 mil ion tons of hydrogen chloride per year. Global release of methyl chloride from biota and from burning biomass is estimated at 4 mil ion tons per year. These quantities dwarf the release of these compounds from industry yet the global chemical industry is often seen (including by students of biological sciences) as the major contributor to the presence of environmental y damaging halogenated compounds in the environment. In addition to these simple molecules, living organisms, especial y those from marine sources, produce a large number of more complex organo-halogens, many of which have biological/pharmacological activity. In the last 30 years, more than 3000 such compounds have been isolated and characterised, including polychlorinated pyrroles similar to PCBs and polybrominated dioxins as wel as novel compounds with antibiotic, analgesic, anti-inflammatory and anti-cancer activities. Many of the organo-halogens with therapeutic potential are of marine origin. If they are to be exploited sustainably, then we need to encourage inter-disciplinary work between marine biologists and chemists. Such work needs to start at the undergraduate level. The aim of this project is to build on current work with biologists and develop practical work that wil be suitable for inter-disciplinary student groups of chemists and marine biologists. The marine biology students wil gain from working with chemistry students by having to communicate the opportunities for developing joint chemical and biotechnological approaches to exploiting marine natural products from ecological y-fragile sources. Chemists wil benefit by having to work with biologists to develop ‘green chemistry’ approaches using enzymes for in vitro routes to the production of marine natural products. In the first phase of the work students wil focus on using haloperoxidase enzymes to catalyse the in vitro production of several model • The synthesis of bromoform from 3-oxooctanoic acid • The bromination of trans-stilbene • The bromination of indene and subsequent synthesis of indene oxide, a precursor used in the synthesis of the HIV-1 protease inhibitor Students wil also work together to study the decolourisation of synthetic dye residues by marine macroalgae (seaweeds) to examine the potential for dye factory effluent treatment by seaweed beds.
References:
Butler, A. and Carter-Franklin, J. N. (2004) The role of vanadium bromoperoxidase in the biosynthesis of halogenated marine natural products. Nat. Prod. Rep. 21, 180 - 188.
Gribble, G. W. (2004) Natural Organohalogens: A New Frontier for Medicinal Agents? J. Chem. Educ. 81(10), 1441 - 1449.
Harper, D. B. (2000) The Global Chloromethane Cycle: biosynthesis, biodegradation and metabolic role. Nat. Prod. Rep. 17, 337 - 348.
Hjeresen, D. L. Schutt, D. L. and Boese, J. M. (2000) Green Chemistry and Education. J. Chem. Educ. 77(12), 1543 - 1547.
Jervis, L., Jervis, L. M. and Giovannel i, D. (2005) Aligning Biochemistry to the Interests of Biology Students Using haloperoxidase to il ustrate reactions of environmental and biomedical importance. Biochemical and Molecular Biology Education, 33 (4), 293 – 301. Littlechild, J. (1999) Current Opinion in Chemical Biology, 3, 28 – 34. Haloperoxidases and their role in biotransformation reactions Manley, S. L. (2002) Biogeochem. 60, 163 – 180. Phytogenesis of McKenzie, L., Huffman, L. M. and Hutchison, J. E. (2005) J. Chem. Ed. 82(2), 306 – 310. The evolution of a green chemistry laboratory experiment: Greener Murphy, C. D. (2003) New frontiers in biological halogenation. J. Appl Microbiol. 94, 539 - 548.
Scheuer, P. J. (1999) Exploring the Ocean - Stating the Case for Chemistry. J. Chem. Educ. 76(8), 1075 - 1079
Steinhart, C. E. (2001) J. Chem. Ed. 78(11), 1444. Biology of the Blues

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