TY - JOUR
T1 - Fluorinated sterols are suicide inhibitors of ergosterol biosynthesis and growth in trypanosoma brucei
AU - Leaver, David J.
AU - Patkar, Presheet
AU - Singha, Ujjal K.
AU - Miller, Matthew B.
AU - Haubrich, Brad A.
AU - Chaudhuri, Minu
AU - Nes, W. David
N1 - Publisher Copyright:
© 2015 Elsevier Ltd All rights reserved.
PY - 2015/10/22
Y1 - 2015/10/22
N2 - Trypanosoma brucei, the causal agent for sleeping sickness, depends on ergosterol for growth. Here, we describe the effects of a mechanism-based inhibitor, 26-fluorolanosterol (26FL), which converts in vivo to a fluorinated substrate of the sterol C24-methyltransferase essential for sterol methylation and function of ergosterol, and missing from the human host. 26FL showed potent inhibition of ergosterol biosynthesis and growth of procyclic and bloodstream forms while having no effect on cholesterol biosynthesis or growth of human epithelial kidney cells. During exposure of cloned TbSMT to 26-fluorocholesta- 5,7,24-trienol, the enzyme is gradually killed as a consequence of the covalent binding of the intermediate C25 cation to the active site (kcat/kinact = 0.26 min-1/0.24 min-1; partition ratio of 1.08), whereas 26FL is non-productively bound. These results demonstrate that poisoning of ergosterol biosynthesis by a 26-fluorinated Δ24-sterol is a promising strategy for developing a new treatment for trypanosomiasis.
AB - Trypanosoma brucei, the causal agent for sleeping sickness, depends on ergosterol for growth. Here, we describe the effects of a mechanism-based inhibitor, 26-fluorolanosterol (26FL), which converts in vivo to a fluorinated substrate of the sterol C24-methyltransferase essential for sterol methylation and function of ergosterol, and missing from the human host. 26FL showed potent inhibition of ergosterol biosynthesis and growth of procyclic and bloodstream forms while having no effect on cholesterol biosynthesis or growth of human epithelial kidney cells. During exposure of cloned TbSMT to 26-fluorocholesta- 5,7,24-trienol, the enzyme is gradually killed as a consequence of the covalent binding of the intermediate C25 cation to the active site (kcat/kinact = 0.26 min-1/0.24 min-1; partition ratio of 1.08), whereas 26FL is non-productively bound. These results demonstrate that poisoning of ergosterol biosynthesis by a 26-fluorinated Δ24-sterol is a promising strategy for developing a new treatment for trypanosomiasis.
UR - http://www.scopus.com/inward/record.url?scp=84950263097&partnerID=8YFLogxK
U2 - 10.1016/j.chembiol.2015.08.017
DO - 10.1016/j.chembiol.2015.08.017
M3 - Article
C2 - 26496686
AN - SCOPUS:84950263097
SN - 1074-5521
VL - 22
SP - 1374
EP - 1383
JO - Chemistry and Biology
JF - Chemistry and Biology
IS - 10
ER -