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Therapeutics from Microbes: Pathways and Specific Examples. Blaine Pfeifer Department of Chemical & Biological Engineering Tufts University Medford, MA 02155, U.S.A. FMM Industry Day February 23, 2011. Motivation I – Range of therapeutics and activities. Penicillium chrysogenum.
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Therapeutics from Microbes: Pathways and Specific Examples Blaine Pfeifer Department of Chemical & Biological Engineering Tufts University Medford, MA 02155, U.S.A. FMM Industry Day February 23, 2011
Motivation I – Range of therapeutics and activities Penicilliumchrysogenum Artemisia annua Salinosporatropica Penicillin Artemisinin Lomaiviticin Antibiotic Antimalarial Anticancer
Motivation II – Market value and emerging drug resistance • NCE’s between 1981 and 2006 • 34% were natural products or semi-synthetic derivatives • Global antibacterial market generated $42 billion in sales in 2009 • ~4% annual growth over last five years • MRSA, VRSA, other antibiotic resistant microbes in community and hospital environments • Now, MRSA kills more U.S. citizens each year than AIDS • Infectious Diseases Society of America “10 by ‘20” initiative Pollack A. New York Times. 2010 Nov 10. Clin Infect Dis. 2010 Apr 15;50(8):1081-3. Hasmad B. Nat Rev Drug Discov. 2010 Sep;9(9):675-6. Newman DJ, Cragg GM. J Nat Prod. 2007 Mar;70(3):461-77.
Challenges I –Intractable natural sources Penicilliumchrysogenum Artemisia annua Salinosporatropica Penicillin Artemisinin Lomaiviticin Antibiotic Antimalarial Anticancer
Challenges II – Molecular complexity Penicilliumchrysogenum Artemisia annua Salinosporatropica Penicillin Artemisinin Lomaiviticin Antibiotic Antimalarial Anticancer
Approach I –Heterologous Biosynthesis Heterologous Expression Identification & Isolation GeneA GeneA GeneB GeneC Escherichia coli GeneB GeneC • Scientific Motivation: • Complex, slow-growing organisms • Complex chemistry • Vast knowledge • Eventual Outcome: • Therapeutic access • Less expensive drugs • Widespread use • Challenges: • Uncompetitive production titers
Examples – Erythromycin and Taxol Saccharopolysporaerythraea Polyketide Propionyl-CoA 6 × (2S)-Methymalonyl-CoA 6-Deoxyerythronolide B Erythromycin CarbonSource(s) Isoprenoid 3 × IPP Taxusbrevifolia DMAPP Taxadiene Taxol
Erythromycin – Complete heterologous biosynthesis Zhang H, et al. Chem Biol. 2010 Nov;17(11):1232-40. Pfeifer BA, et al. Science. 2001 Mar;291(5509):1790-2.
Pyruvate 2C-methyl-D-erythritol-4-phosphate (MEP) 1-deoxy-D-xylulose-5-phosphate (DXP) DXR IspE DXS IspD CDP-MEP CDP-ME Glyceraldehyde 3-phosphate IspF IPP IspH IspG MEC HMBPP GGPPS 5α TXS IDI DMAPP Taxol – Isoprenoid pathway optimization Plasmid, promoter, strain combinations Ajikumar PK, et al. Science. 2010 Oct 1;330(6000):70-4.
Opportunities I – Access Nature’s potential • 25 predicted polyketide, nonribosomal peptide, and terpene gene clusters • No products derived from these clusters (besides erythromycin) were indentified on 50 different types of solid and liquid media Boakes S, et al. J Mol Microbiol Biotechnol. 2004;8(2):73-80. Oliynyk M, et al. Nat Biotechnol. 2007 Apr;25(4):447-53.
Opportunities II – Manipulate biosynthesis DEBS1 DEBS2 Tailoring Enzymes DEBS3 Propionate Sfp PrpE PCC DEBS1 Propionate DEBS2 Tailoring Enzymes DEBS3 Sfp PrpE PCC Benzoate Zhang H, et al. 2011. In preparation.
Opportunities III – Production speed and economy ~Days ~Days Process Time: ~100 years ~Weeks ~Weeks ~Weeks 100 year old tree → 3 kg bark →300 mg Taxol → 1 dose! A. thalianaHeterologous E. coli Heterologous T. canadensisCell-Culture Tomato Heterologous S. cerevisiae Heterologous T. brevifoliaExtraction (Horwitz 1994 Nature) (Ketchum, et al.1998 B&B) (Besumbes, et al.2004 B&B) (Kovacs, et al. 2007 Transgenic Res) (Engels, et al. 2008Metab Eng) (Ajikumar, et al. 2010 Science)
6dEB (mg/L) Tryptone Trace Metals Opportunities IV – High(er) throughput process optimization -Media optimization through 96-well format Defined Medium: -Potassium Phosphates -Ammonium Sulfate -Glycerol -Magnesium Sulfate -Vitamins -Trace Metals LB Medium: -Yeast Extract -NaCl -Tryptone HPLC-ELSD Analysis 96-well format Plackett-Burman Screening: LB Medium: -Yeast Extract -NaCl -Tryptone Enhanced Medium: -Yeast Extract -Tryptone -Glycerol -NaCl -Vitamins -Trace Metals Defined Medium: -Potassium Phosphates -Ammonium Sulfate -Glycerol -Magnesium Sulfate -Vitamins -Trace Metals Pistorino M, Pfeifer BA. BiotechnolProg. 2009 Sep-Oct;25(5):1364-71.
Acknowledgements • Students: • Haoran Zhang • Brett Boghigian • Jiequn Wu • Karin Skalina • Yong Wang • Funding/Collaborators: • NIH (AI074224; GM085323) • NSF (0712019; 0924699) • Milheim Foundation • Greg Stephanopoulos (MIT)