IMED2001 Study Guide - Final Guide: Daptomycin, Antibiotics, Lipid Bilayer
30 Jun 2018
School
Department
Course
Professor
IMED2001: Revision Notes 6
AB Action:!
Inhibition of CW synthesis:
- 2 classes: beta lectems and glycopeptide!
-Transpeptidases help with cross-linking and elongation of peptidoglycan!
-Glycopeptides bind D-ala!
-When peptidoglycan cannot lengthen and cross link = weak CW = bacteria burst due to
osmotic pressure!
Interfere with protein production:
-Rifamycin affects transcription and translation!
-By inhibiting enzyme needed for production of mRNA = no protein production = affects
production of mRNA!
-Macrolides (eg. Clindamycin)
-bind to 50S subunit to bacterial ribosome = NO PROTEIN ELONGATION = affects
function of tRNA
-Tetracyclines
-Block binding of tRNA
-Binds to 30S = cannot add new AA!
- Aminoglycosides!
-bind to 30S = misread code!
Folate synthesis inhibition:
-Sulphonamides
-Competes with PABA!
-No folate = DNA and RNA precursors cannot be produced = bacteria cannot survive!
-Trimethoprim !
-Inhibits DHF reductase!
-No folate = DNA and RNA precursors cannot be produced = bacteria cannot survive!
Interfere with DNA replication and function:
-Quinolones
-Inhibit DNA gyrate and DNA topoisomerase (bacterial enzymes)!
-Which are involved in DNA replication and function!
Document Summary
Transpeptidases help with cross-linking and elongation of peptidoglycan. When peptidoglycan cannot lengthen and cross link = weak cw = bacteria burst due to osmotic pressure. By inhibiting enzyme needed for production of mrna = no protein production = a ects production of mrna. Bind to 50s subunit to bacterial ribosome = no protein elongation = a ects function of trna. Binds to 30s = cannot add new aa. No folate = dna and rna precursors cannot be produced = bacteria cannot survive. Inhibit dna gyrate and dna topoisomerase (bacterial enzymes) Which are involved in dna replication and function. = no dna replication = no mrna production = no proteins. Lipopeptides (daptomycin) = to do with insertion of lipid membrane. Lipophilic side chain inserts into lipid membrane. E ux pumps: don"t let ab accumulate within bacteria so cannot attack targets. Inhibit permeability of outer membrane (only in gn) Gene regulation change in porin structure and function.
