Imam Fathoni, Terence C S Ho, Alex H Y Chan, Finian J Leeper, Kai Matuschewski, Kevin J Saliba
{"title":"具有抗疟活性的硫胺素类似物的鉴定和表征。","authors":"Imam Fathoni, Terence C S Ho, Alex H Y Chan, Finian J Leeper, Kai Matuschewski, Kevin J Saliba","doi":"10.1128/aac.01096-24","DOIUrl":null,"url":null,"abstract":"<p><p>Thiamine is metabolized into thiamine pyrophosphate (TPP), an essential enzyme cofactor. Previous work has shown that oxythiamine, a thiamine analog, is metabolized by thiamine pyrophosphokinase (TPK) into oxythiamine pyrophosphate within the malaria parasite <i>Plasmodium falciparum</i> and then inhibits TPP-dependent enzymes, killing the parasite <i>in vitro</i> and <i>in vivo</i>. To identify a more potent antiplasmodial thiamine analog, 11 commercially available compounds were tested against <i>P. falciparum</i> and <i>P. knowlesi</i>. Five active compounds were identified, but only N3-pyridyl thiamine (N3PT), a potent transketolase inhibitor and candidate anticancer lead compound, was found to suppress <i>P. falciparum</i> proliferation with an IC<sub>50</sub> value 10-fold lower than that of oxythiamine. N3PT was active against <i>P. knowlesi</i> and was >17 times less toxic to human fibroblasts, as compared to oxythiamine. Increasing the extracellular thiamine concentration reduced the antiplasmodial activity of N3PT, consistent with N3PT competing with thiamine/TPP. A transgenic <i>P. falciparum</i> line overexpressing TPK was found to be hypersensitized to N3PT. Docking studies showed an almost identical binding mode in TPK between thiamine and N3PT. Furthermore, we show that [<sup>3</sup>H]thiamine accumulation, resulting from a combination of transport and metabolism, in isolated parasites is reduced by N3PT. Treatment of <i>P. berghei</i>-infected mice with 200 mg/kg/day N3PT reduced their parasitemia, prolonged their time to malaria symptoms, and appeared to be non-toxic to mice. Collectively, our studies are consistent with N3PT competing with thiamine for TPK binding and inhibiting parasite proliferation by reducing TPP production, and/or being converted into a TPP antimetabolite that inhibits TPP-dependent enzymes.</p>","PeriodicalId":8152,"journal":{"name":"Antimicrobial Agents and Chemotherapy","volume":" ","pages":"e0109624"},"PeriodicalIF":4.1000,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11619390/pdf/","citationCount":"0","resultStr":"{\"title\":\"Identification and characterization of thiamine analogs with antiplasmodial activity.\",\"authors\":\"Imam Fathoni, Terence C S Ho, Alex H Y Chan, Finian J Leeper, Kai Matuschewski, Kevin J Saliba\",\"doi\":\"10.1128/aac.01096-24\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Thiamine is metabolized into thiamine pyrophosphate (TPP), an essential enzyme cofactor. Previous work has shown that oxythiamine, a thiamine analog, is metabolized by thiamine pyrophosphokinase (TPK) into oxythiamine pyrophosphate within the malaria parasite <i>Plasmodium falciparum</i> and then inhibits TPP-dependent enzymes, killing the parasite <i>in vitro</i> and <i>in vivo</i>. To identify a more potent antiplasmodial thiamine analog, 11 commercially available compounds were tested against <i>P. falciparum</i> and <i>P. knowlesi</i>. Five active compounds were identified, but only N3-pyridyl thiamine (N3PT), a potent transketolase inhibitor and candidate anticancer lead compound, was found to suppress <i>P. falciparum</i> proliferation with an IC<sub>50</sub> value 10-fold lower than that of oxythiamine. N3PT was active against <i>P. knowlesi</i> and was >17 times less toxic to human fibroblasts, as compared to oxythiamine. Increasing the extracellular thiamine concentration reduced the antiplasmodial activity of N3PT, consistent with N3PT competing with thiamine/TPP. A transgenic <i>P. falciparum</i> line overexpressing TPK was found to be hypersensitized to N3PT. Docking studies showed an almost identical binding mode in TPK between thiamine and N3PT. Furthermore, we show that [<sup>3</sup>H]thiamine accumulation, resulting from a combination of transport and metabolism, in isolated parasites is reduced by N3PT. Treatment of <i>P. berghei</i>-infected mice with 200 mg/kg/day N3PT reduced their parasitemia, prolonged their time to malaria symptoms, and appeared to be non-toxic to mice. Collectively, our studies are consistent with N3PT competing with thiamine for TPK binding and inhibiting parasite proliferation by reducing TPP production, and/or being converted into a TPP antimetabolite that inhibits TPP-dependent enzymes.</p>\",\"PeriodicalId\":8152,\"journal\":{\"name\":\"Antimicrobial Agents and Chemotherapy\",\"volume\":\" \",\"pages\":\"e0109624\"},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2024-12-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11619390/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Antimicrobial Agents and Chemotherapy\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1128/aac.01096-24\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/10/29 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q2\",\"JCRName\":\"MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Antimicrobial Agents and Chemotherapy","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1128/aac.01096-24","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/10/29 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
Identification and characterization of thiamine analogs with antiplasmodial activity.
Thiamine is metabolized into thiamine pyrophosphate (TPP), an essential enzyme cofactor. Previous work has shown that oxythiamine, a thiamine analog, is metabolized by thiamine pyrophosphokinase (TPK) into oxythiamine pyrophosphate within the malaria parasite Plasmodium falciparum and then inhibits TPP-dependent enzymes, killing the parasite in vitro and in vivo. To identify a more potent antiplasmodial thiamine analog, 11 commercially available compounds were tested against P. falciparum and P. knowlesi. Five active compounds were identified, but only N3-pyridyl thiamine (N3PT), a potent transketolase inhibitor and candidate anticancer lead compound, was found to suppress P. falciparum proliferation with an IC50 value 10-fold lower than that of oxythiamine. N3PT was active against P. knowlesi and was >17 times less toxic to human fibroblasts, as compared to oxythiamine. Increasing the extracellular thiamine concentration reduced the antiplasmodial activity of N3PT, consistent with N3PT competing with thiamine/TPP. A transgenic P. falciparum line overexpressing TPK was found to be hypersensitized to N3PT. Docking studies showed an almost identical binding mode in TPK between thiamine and N3PT. Furthermore, we show that [3H]thiamine accumulation, resulting from a combination of transport and metabolism, in isolated parasites is reduced by N3PT. Treatment of P. berghei-infected mice with 200 mg/kg/day N3PT reduced their parasitemia, prolonged their time to malaria symptoms, and appeared to be non-toxic to mice. Collectively, our studies are consistent with N3PT competing with thiamine for TPK binding and inhibiting parasite proliferation by reducing TPP production, and/or being converted into a TPP antimetabolite that inhibits TPP-dependent enzymes.
期刊介绍:
Antimicrobial Agents and Chemotherapy (AAC) features interdisciplinary studies that build our understanding of the underlying mechanisms and therapeutic applications of antimicrobial and antiparasitic agents and chemotherapy.