Enzymes of Purine Salvage Pathway in Trypanosoma brucei and Trypanocidal Action of Acyclic Nucleoside Phosphonates

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F14%3A00488325" target="_blank" >RIV/60077344:_____/14:00488325 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388963:_____/14:00488325

Výsledek na webu

<a href="http://www.parazitologie.cz/protozoologie/Protodny2014/JPD_sbornik_2014.pdf" target="_blank" >http://www.parazitologie.cz/protozoologie/Protodny2014/JPD_sbornik_2014.pdf</a>

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Enzymes of Purine Salvage Pathway in Trypanosoma brucei and Trypanocidal Action of Acyclic Nucleoside Phosphonates

Popis výsledku v původním jazyce

Trypanosoma brucei is a medically and veterinary important protozoan parasite. Since commonly used drugs are toxic and inefficient against the diseases caused by this pathogen, it is necessary to search for new therapeutic alternatives. Unlike mammals, T. brucei cannot synthesize purines de novo and it depends strictly on the uptake of these essential molecules from its environment. To transform, interconvert and metabolize purines, complex and versatile purine salvage pathway (PSP) has evolved in these purine auxotrophs. Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and xanthine PRT (XPRT) are two key enzymes of the redundant PSP in T. brucei. RNAi silencing of the glycosomal XPRT led to a strong growth phenotype in the media containing only xanthine while no growth phenotype was observed when hypoxanthine was added. RNAi silencing of the cytosolic HGPRT resulted in slight phenotype in the media containing hypoxanthine suggesting that XPRT can also act on hypoxanthine when HGPRT is ablated. Moreover, the double-knock down of HGPRT/XPRT was lethal when 6-oxo purines were the only purine sources in the media implying that no other enzymes can circumvent the action of PRTs. In vitro studies confirmed affinity of the recombinant HGPRT to hypoxanthine or guanine and not to xanthine. Moreover, we screened nearly 100 acyclic nucleoside phosphonates (ANPs), which are potential inhibitors of HGPRT and XPRT. Some of the ANPs have the effective 50% inhibitory concentration (IC50) in the single jM values. The mode of action of these drugs was studied using a cell line overexpressing the v5-tagged HGPRT suggesting that ANPs binds to and inhibit the activity of the HGPRT enzyme.

Název v anglickém jazyce

Enzymes of Purine Salvage Pathway in Trypanosoma brucei and Trypanocidal Action of Acyclic Nucleoside Phosphonates

Popis výsledku anglicky

Trypanosoma brucei is a medically and veterinary important protozoan parasite. Since commonly used drugs are toxic and inefficient against the diseases caused by this pathogen, it is necessary to search for new therapeutic alternatives. Unlike mammals, T. brucei cannot synthesize purines de novo and it depends strictly on the uptake of these essential molecules from its environment. To transform, interconvert and metabolize purines, complex and versatile purine salvage pathway (PSP) has evolved in these purine auxotrophs. Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and xanthine PRT (XPRT) are two key enzymes of the redundant PSP in T. brucei. RNAi silencing of the glycosomal XPRT led to a strong growth phenotype in the media containing only xanthine while no growth phenotype was observed when hypoxanthine was added. RNAi silencing of the cytosolic HGPRT resulted in slight phenotype in the media containing hypoxanthine suggesting that XPRT can also act on hypoxanthine when HGPRT is ablated. Moreover, the double-knock down of HGPRT/XPRT was lethal when 6-oxo purines were the only purine sources in the media implying that no other enzymes can circumvent the action of PRTs. In vitro studies confirmed affinity of the recombinant HGPRT to hypoxanthine or guanine and not to xanthine. Moreover, we screened nearly 100 acyclic nucleoside phosphonates (ANPs), which are potential inhibitors of HGPRT and XPRT. Some of the ANPs have the effective 50% inhibitory concentration (IC50) in the single jM values. The mode of action of these drugs was studied using a cell line overexpressing the v5-tagged HGPRT suggesting that ANPs binds to and inhibit the activity of the HGPRT enzyme.

Druh

O - Ostatní výsledky

CEP obor

—

OECD FORD obor

10608 - Biochemistry and molecular biology

Projekt

<a href="/cs/project/LL1205" target="_blank" >LL1205: Charakterizace unikátních vlastností esenciální FoF1 ATP syntázy u původce africké spavé nemoci Trypanosoma bucei za účelem vývoje inhibitorů tohoto komplexu.</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2014

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů