TY - JOUR
T1 - Relaxed Substrate Requirements of Sterol 14α-Demethylase from Naegleria fowleri Are Accompanied by Resistance to Inhibition
AU - Hargrove, Tatiana Y.
AU - Wawrzak, Zdzislaw
AU - Rachakonda, Girish
AU - Nes, W. David
AU - Villalta, Fernando
AU - Guengerich, F. Peter
AU - Lepesheva, Galina I.
N1 - Funding Information:
This work was supported by National Institutes of Health Grants R01 GM067871 (G.I.L.). Synthesis of compounds at the Vanderbilt Chemical Synthesis Core Facility was supported by R01 GM067871-15S1 (Administrative Supplement) (G.I.L.). Synthesis of the sterols was supported by R33 AI119782 (W.D.N.). Vanderbilt University is a member institution of the Life Sciences Collaborative Access Team at Sector 21 of the Advanced Photon Source (Argonne, IL). Use of the Advanced Photon Source at Argonne National Laboratory was supported by the United States Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract DE-AC02-06CH11357.
Publisher Copyright:
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PY - 2021/12/9
Y1 - 2021/12/9
N2 - Naegleria fowleri is the protozoan pathogen that causes primary amoebic meningoencephalitis (PAM), with the death rate exceeding 97%. The amoeba makes sterols and can be targeted by sterol biosynthesis inhibitors. Here, we characterized N. fowleri sterol 14-demethylase, including catalytic properties and inhibition by clinical antifungal drugs and experimental substituted azoles with favorable pharmacokinetics and low toxicity. None of them inhibited the enzyme stoichiometrically. The highest potencies were displayed by posaconazole (IC50 = 0.69 μM) and two of our compounds (IC50 = 1.3 and 0.35 μM). Because both these compounds penetrate the brain with concentrations reaching minimal inhibitory concentration (MIC) values in an N. fowleri cellular assay, we report them as potential drug candidates for PAM. The 2.1 Å crystal structure, in complex with the strongest inhibitor, provides an explanation connecting the enzyme weaker substrate specificity with lower sensitivity to inhibition. It also provides insight into the enzyme/ligand molecular recognition process and suggests directions for the design of more potent inhibitors.
AB - Naegleria fowleri is the protozoan pathogen that causes primary amoebic meningoencephalitis (PAM), with the death rate exceeding 97%. The amoeba makes sterols and can be targeted by sterol biosynthesis inhibitors. Here, we characterized N. fowleri sterol 14-demethylase, including catalytic properties and inhibition by clinical antifungal drugs and experimental substituted azoles with favorable pharmacokinetics and low toxicity. None of them inhibited the enzyme stoichiometrically. The highest potencies were displayed by posaconazole (IC50 = 0.69 μM) and two of our compounds (IC50 = 1.3 and 0.35 μM). Because both these compounds penetrate the brain with concentrations reaching minimal inhibitory concentration (MIC) values in an N. fowleri cellular assay, we report them as potential drug candidates for PAM. The 2.1 Å crystal structure, in complex with the strongest inhibitor, provides an explanation connecting the enzyme weaker substrate specificity with lower sensitivity to inhibition. It also provides insight into the enzyme/ligand molecular recognition process and suggests directions for the design of more potent inhibitors.
UR - http://www.scopus.com/inward/record.url?scp=85120635752&partnerID=8YFLogxK
U2 - 10.1021/acs.jmedchem.1c01710
DO - 10.1021/acs.jmedchem.1c01710
M3 - Article
C2 - 34842434
AN - SCOPUS:85120635752
SN - 0022-2623
VL - 64
SP - 17511
EP - 17522
JO - Journal of Medicinal Chemistry
JF - Journal of Medicinal Chemistry
IS - 23
ER -