GTP analogue inhibits polymerization and GTPase activity of the bacterial protein FtsZ without affecting its eukaryotic homologue tubulin.
The prokaryotic tubulin homologue FtsZ plays a key role in bacterial cell division. Selective inhibitors of the GTP-dependent polymerization of FtsZ are expected to result in a new class of antibacterial agents. One of the challenges is to identify compounds which do not affect the function of tubulin and various other GTPases in eukaryotic cells. We have designed a novel inhibitor of FtsZ polymerization based on the structure of the natural substrate GTP. The inhibitory activity of 8-bromoguanosine 5'-triphosphate (BrGTP) was characterized by a coupled assay, which allows simultaneous detection of the extent of polymerization (via light scattering) and GTPase activity (via release of inorganic phosphate). We found that BrGTP acts as a competitive inhibitor of both FtsZ polymerization and GTPase activity with a Ki for GTPase activity of 31.8 +/- 4.1 microM. The observation that BrGTP seems not to inhibit tubulin assembly suggests a structural difference of the GTP-binding pockets of FtsZ and tubulin.
Läppchen
Tilman
T
Bioorganic Chemistry, Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, The Netherlands.
Hartog
Aloysius F
AF
Pinas
Victorine A
VA
Koomen
Gerrit-Jan
GJ
den Blaauwen
Tanneke
T
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000378:metabolism; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000648:ultrastructure; D001667:Binding, Competitive; D002851:Chromatography, High Pressure Liquid; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000648:ultrastructure; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000378:metabolism; D006868:Hydrolysis; D008027:Light; D012542:Scattering, Radiation
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; C071525:FtsZ protein, Bacteria; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases