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20 Cards in this Set
- Front
- Back
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What to talk about on VSG? |
VSG structure Expression of VSG gene VSG expression site architecture Switching gene expression |
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What drug is used for treating Phase I of infection by T. brucei gambiense? |
Suramin |
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What drug is used for treating Phase II of infection by T. brucei gambiense? |
Pentamidine |
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What drug is used for treating Phase I of infection by T. brucei rhodesiense? |
Melarsoprol |
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What drug is used for treating Phase II of infection by T. brucei rhodesiense? |
Eflornithine |
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Targets of Suramin |
Dihydrofolate reductase Thymidine kinase All glycolytic enzymes |
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Side effects of Suramin |
Vomiting Shock Collapse |
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Targets of Pentamidine |
DNA Many enzymes |
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Side effects of Pentamidine |
Liver, kidney and pancreas failure |
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Comment on the toxicity of melarsoprol |
Melarsoprol is very toxic Contains arsenic 2-3% patients die of treatment-related encephalitis |
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What does melarsoprol have to be administered with? Why? |
Polypropylene glycol It is an anti-freeze. Keep the drug soluble, thus being permeable to cells. |
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What are the limitations of using eflornithine? |
Production is very expensive. Large amount of drugs is required each day. Requires hospitalisation. |
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What are the uptake and efflux transporters of melarsoprol? |
Uptake: Aquaglyceroporin 2 (AQP2) P2 Efflux: MRPA |
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What are the uptake transporters of pentamidine? |
Aquaglyceroporin 2 (AQP2) P2 |
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How does melarsoprol target parasite? |
Mel enters the cell. Mel complexes with trypanothione to form Mel T. Mel T competitively inhibits trypanothione reductase. |
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What does trypanothione reductase do? |
Reduces trypanothione disulfide into trypanothione. This involves the uptake of two free hydrogen ions, which are free radicals, by breaking a disulphide bridge. |
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What is the target of Eflornithine? |
Ornithine Decarboxylase (ODC) |
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What does ornithine decarboxylase (ODC) do? |
It catalyses the conversion of ornithine to putrescine. Putrescine is the precursor of spermidine. spermidine is required for production of trypanothione. |
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Comment on the mechanism of Eflornithine inhibition. |
Eflornithine is a "suicide inhibitor". It binds covalently to and activates ODC. |
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Why is Eflornithine less toxic to human? |
The turnover rate of ODC in human is higher than that in T b. gambiense human: 20 mins gambiense: >18 hours (rhodesiense: ~4 hours, thus rhod. is more resistant to Eflornithine) |
