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1.
Cell ; 183(1): 258-268.e12, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32860739

RESUMEN

Plasmodium species, the causative agent of malaria, rely on glucose for energy supply during blood stage. Inhibition of glucose uptake thus represents a potential strategy for the development of antimalarial drugs. Here, we present the crystal structures of PfHT1, the sole hexose transporter in the genome of Plasmodium species, at resolutions of 2.6 Å in complex with D-glucose and 3.7 Å with a moderately selective inhibitor, C3361. Although both structures exhibit occluded conformations, binding of C3361 induces marked rearrangements that result in an additional pocket. This inhibitor-binding-induced pocket presents an opportunity for the rational design of PfHT1-specific inhibitors. Among our designed C3361 derivatives, several exhibited improved inhibition of PfHT1 and cellular potency against P. falciparum, with excellent selectivity to human GLUT1. These findings serve as a proof of concept for the development of the next-generation antimalarial chemotherapeutics by simultaneously targeting the orthosteric and allosteric sites of PfHT1.


Asunto(s)
Proteínas de Transporte de Monosacáridos/ultraestructura , Plasmodium falciparum/metabolismo , Plasmodium falciparum/ultraestructura , Proteínas Protozoarias/ultraestructura , Secuencia de Aminoácidos , Animales , Antimaláricos , Transporte Biológico , Glucosa/metabolismo , Humanos , Malaria , Malaria Falciparum/parasitología , Proteínas de Transporte de Monosacáridos/química , Proteínas de Transporte de Monosacáridos/metabolismo , Parásitos , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Azúcares/metabolismo
2.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33402433

RESUMEN

Artemisinin-resistant malaria parasites have emerged and have been spreading, posing a significant public health challenge. Antimalarial drugs with novel mechanisms of action are therefore urgently needed. In this report, we exploit a "selective starvation" strategy by inhibiting Plasmodium falciparum hexose transporter 1 (PfHT1), the sole hexose transporter in P. falciparum, over human glucose transporter 1 (hGLUT1), providing an alternative approach to fight against multidrug-resistant malaria parasites. The crystal structure of hGLUT3, which shares 80% sequence similarity with hGLUT1, was resolved in complex with C3361, a moderate PfHT1-specific inhibitor, at 2.3-Å resolution. Structural comparison between the present hGLUT3-C3361 and our previously reported PfHT1-C3361 confirmed the unique inhibitor binding-induced pocket in PfHT1. We then designed small molecules to simultaneously block the orthosteric and allosteric pockets of PfHT1. Through extensive structure-activity relationship studies, the TH-PF series was identified to selectively inhibit PfHT1 over hGLUT1 and potent against multiple strains of the blood-stage P. falciparum Our findings shed light on the next-generation chemotherapeutics with a paradigm-shifting structure-based design strategy to simultaneously target the orthosteric and allosteric sites of a transporter.


Asunto(s)
Antimaláricos/química , Transportador de Glucosa de Tipo 1/genética , Transportador de Glucosa de Tipo 3/ultraestructura , Malaria Falciparum/tratamiento farmacológico , Proteínas de Transporte de Monosacáridos/ultraestructura , Proteínas Protozoarias/ultraestructura , Sitio Alostérico , Secuencia de Aminoácidos/genética , Animales , Cristalografía por Rayos X , Glucosa/metabolismo , Transportador de Glucosa de Tipo 1/antagonistas & inhibidores , Transportador de Glucosa de Tipo 1/química , Transportador de Glucosa de Tipo 3/química , Malaria Falciparum/genética , Malaria Falciparum/parasitología , Proteínas de Transporte de Monosacáridos/antagonistas & inhibidores , Proteínas de Transporte de Monosacáridos/genética , Plasmodium falciparum/química , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidad , Conformación Proteica/efectos de los fármacos , Proteínas Protozoarias/antagonistas & inhibidores , Proteínas Protozoarias/genética , Relación Estructura-Actividad
3.
Angew Chem Int Ed Engl ; 63(8): e202315599, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38169100

RESUMEN

Polypeptides, as natural polyelectrolytes, are assembled into tailored proteins to integrate chromophores and catalytic sites for photosynthesis. Mimicking nature to create the water-soluble nanoassemblies from synthetic polyelectrolytes and photocatalytic molecular species for artificial photosynthesis is still rare. Here, we report the enhancement of the full-spectrum solar-light-driven H2 production within a supramolecular system built by the co-assembly of anionic metalloporphyrins with cationic polyelectrolytes in water. This supramolecular photocatalytic system achieves a H2 production rate of 793 and 685 µmol h-1 g-1 over 24 h with a combination of Mg or Zn porphyrin as photosensitizers and Cu porphyrin as a catalyst, which is more than 23 times higher than that of free molecular controls. With a photosensitizer to catalyst ratio of 10000 : 1, the highest H2 production rate of >51,700 µmol h-1 g-1 with a turnover number (TON) of >1,290 per molecular catalyst was achieved over 24 h irradiation. The hierarchical self-assembly not only enhances photostability through forming ordered stackings of the metalloporphyrins but also facilitates both energy and electron transfer from antenna molecules to catalysts, and therefore promotes the photocatalysis. This study provides structural and mechanistic insights into the self-assembly enhanced photostability and catalytic performance of supramolecular photocatalytic systems.

4.
J Am Chem Soc ; 139(29): 9807-9810, 2017 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-28683547

RESUMEN

Herein, we present the intramolecular [2+2] cycloadditions of dienones promoted through sensitization, using a polypyridyl iridium(III) catalyst, to form bridged cyclobutanes. In contrast to previous examples of straight [2+2] cycloadditions, these efficient crossed additions were achieved under irradiation with visible light. The reactions delivered desired bridged benzobicycloheptanone products with excellent regioselectivity in high yields (up to 96%). This process is superior to previous syntheses of benzobicyclo[3.1.1]heptanones, which are readily converted to B-norbenzomorphan analogues of biological significance. Electrochemical, computational, and spectroscopic studies substantiated the mechanism of triplet energy transfer and explained the unusual regiocontrol.


Asunto(s)
Reacción de Cicloadición , Ciclobutanos/síntesis química , Transferencia de Energía/efectos de la radiación , Cetonas/química , Luz , Procesos Fotoquímicos , Catálisis , Ciclobutanos/química , Iridio/química , Estructura Molecular
5.
Chem Commun (Camb) ; 60(66): 8724-8727, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39072360

RESUMEN

Our investigation has unveiled a series of pyridine-based SARM1 inhibitors, with the lead compound TH-408 exhibiting remarkable potency, achieving an IC50 value of 0.46 µM. This exceptional inhibitory effect significantly curtailed SARM1-mediated cell death across diverse biological models. This finding highlights the promising therapeutic potential for neurodegenerative disorders by disrupting SARM1 activation and advances our understanding of molecular interventions in these complex disorders, including the regulation of NAD+ metabolism.


Asunto(s)
Proteínas del Dominio Armadillo , Muerte Celular , Proteínas del Citoesqueleto , Piridinas , Piridinas/farmacología , Piridinas/química , Piridinas/síntesis química , Humanos , Proteínas del Citoesqueleto/antagonistas & inhibidores , Proteínas del Citoesqueleto/metabolismo , Muerte Celular/efectos de los fármacos , Proteínas del Dominio Armadillo/metabolismo , Proteínas del Dominio Armadillo/antagonistas & inhibidores , NAD+ Nucleosidasa/metabolismo , NAD+ Nucleosidasa/antagonistas & inhibidores , NAD+ Nucleosidasa/química , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/síntesis química , Relación Estructura-Actividad , Estructura Molecular
6.
J Med Chem ; 67(11): 8630-8641, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38747630

RESUMEN

A novel Fe(III) complex, Fe-tBPCDTA, was synthesized and explored as a potential contrast agent for MRI. Compared to established agents like Fe-EDTA and Fe-tCDTA, Fe-tBPCDTA exhibited moderate relaxivity (r1 = 1.17 s-1·mmol-1) due to its enhanced second-sphere mechanism. It also displayed improved kinetic inertness, lower cytotoxicity, and enhanced redox stability. In vivo studies demonstrated its function as an extracellular fluid agent, providing tumor contrast comparable to that of Gd-DTPA at a higher dosage. Complete renal clearance occurred within 24 h. These findings suggest Fe-tBPCDTA as a promising candidate for further development as a safe and effective extracellular MRI contrast agent.


Asunto(s)
Medios de Contraste , Quelantes del Hierro , Imagen por Resonancia Magnética , Organofosfonatos , Medios de Contraste/química , Medios de Contraste/síntesis química , Imagen por Resonancia Magnética/métodos , Animales , Humanos , Organofosfonatos/química , Organofosfonatos/síntesis química , Quelantes del Hierro/química , Quelantes del Hierro/farmacología , Quelantes del Hierro/síntesis química , Compuestos Férricos/química , Ratones , Línea Celular Tumoral , Quelantes/química , Quelantes/síntesis química
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