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Publication Abstract from PubMed

Infection with the free-living amoeba Naegleria fowleri leads to life-threatening primary amoebic meningoencephalitis. Efficacious treatment options for these infections are limited, and the mortality rate is very high ( approximately 98%). Parasite metabolism may provide suitable targets for therapeutic design. Like most other organisms, glucose metabolism is critical for parasite viability, being required for growth in culture. The first enzyme required for glucose metabolism is typically a hexokinase (HK), which transfers a phosphate from ATP to glucose. The products of this enzyme are required for both glycolysis and the pentose phosphate pathway. However, the N. fowleri genome lacks an obvious HK homolog and instead harbors a glucokinase (Glck). The N. fowleri Glck (NfGlck) shares limited (25%) amino acid identity with the mammalian host enzyme (Homo sapiens Glck), suggesting that parasite-specific inhibitors with anti-amoeba activity can be generated. Following heterologous expression, NfGlck was found to have a limited hexose substrate range, with the greatest activity observed with glucose. The enzyme had apparent Km values of 42.5 +/- 7.3 muM and 141.6 +/- 9.9 muM for glucose and ATP, respectively. The NfGlck structure was determined and refined to 2.2-A resolution, revealing that the enzyme shares greatest structural similarity with the Trypanosoma cruzi Glck. These similarities include binding modes and binding environments for substrates. To identify inhibitors of NfGlck, we screened a small collection of inhibitors of glucose-phosphorylating enzymes and identified several small molecules with 50% inhibitory concentration values of <1 muM that may prove useful as hit chemotypes for further leads and therapeutic development against N. fowleri.

Enzymatic and Structural Characterization of the Naegleria fowleri Glucokinase.,Milanes JE, Suryadi J, Abendroth J, Van Voorhis WC, Barrett KF, Dranow DM, Phan IQ, Patrick SL, Rozema SD, Khalifa MM, Golden JE, Morris JC Antimicrob Agents Chemother. 2019 Apr 25;63(5). pii: AAC.02410-18. doi:, 10.1128/AAC.02410-18. Print 2019 May. PMID:30783001^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.