Healthbots: Controlling Hyperglycemia

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HealthbotsControlling Hyperglycemia

• Doug Tischer
• 5.8.08

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Hyperglycemia

• Acute Symptoms

• Chronic Symptoms

• Excessive hunger
• Excessive urination
• Excessive thirst
• Coma

• Blindness
• Neuropathy numbness of toes, feet, fingers
• Poor wound healing
• Hardening of blood vessels
• Kidney disease

Normal blood glucose range 300 400 uM
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The Solution

• Add E. coli to the blood
• Absorb excess glucose if above 400 uM
• Chassis Developed by UC Berekely 2007 iGEM
  project

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Abilities

• Survive for a long time (days) in the blood
  stream
• Does not replicate
• Consume glucose in excess of 400 uM

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Glucose ImportPhosphotransferase System (PTS)
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Important Genes, Proteins and Functions
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Modifications

• Decrease EIIBCGlc Mlc binding affinity
• Mlc separates from EIIBCGlc at higher glucose
• Mlc binds ptsG promoter
• Reduced EIIBCGlc expression
• Less glucose import
• Enhance Mlc inhibition (currently about 18x)
• Mutate Mlc DNA binding sites
• Add more Mlc binding sites in promoter
• Degradation tag on EIIBCGlc
• Combats leakiness of (any) inhibitor

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Modifications Cont.

• ptsG mRNA destabalization
• sRNA SgrS binds the mRNA
• Promoted by glucose-6-P or analog (a-GM-6-P)
• Produce glucose analogs in vivo
• Alpha-methyl-glucose

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Possible Projects

• Mutate EIIBCGlc binding site
• Mutate Mlc (protein) binding site
• Mutate promoter sequences/add more Mlc binding
  sites
• Degradation tag on EIIBCGlc determine half life

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Possible Outcomes

• Total success E. coli consume glucose as usual,
  but stop once extracellular glucose
  concentrations reach 400 uM.
• Partial success E. coli stop consuming glucose
  at some point, just not at 400 uM.
• Interesting Modulated glucose uptake.

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References

• Deutscher, J., Francke, C. and Postma, P.W. 2006.
  How Phosphotransferase System-Related Protein
  Phosphorylation Regulates Carbohydrate Metabolism
  in Bactertia. Microbial and Molecular Biology
  Reviews. 2006 939-1031