RESUMO
Antiviral alpha-P-borano substituted NTPs are promising chain terminators targeting HIV reverse transcriptase (RT). Activation of antiviral nucleoside diphosphates (NDPs) to NTPs may be carried out by pyruvate kinase (PK) and creatine kinase (CK). Herein, are presented the effects of nucleobase, ribose, and alpha-phosphate substitutions on substrate specificities of CK and PK. Both enzymes showed two binding modes and negative cooperativity with respect to substrate binding. The stereospecificity and inhibition of ADP phosphorylation by alpha-P-borano substituted NDP (NDPalphaB) stereoisomers were also investigated. The Sp-ADPalphaB isomer was a 70-fold better substrate for CK than the Rp isomer, whereas PK preferred the Rp isomer of NDPalphaBs. For CK, the Sp-ADPalphaB isomer was a competitive inhibitor; for PK, the Rp-ADPalphaB isomer was a poor competitive inhibitor and the Sp-ADPalphaB isomer was a poor non-competitive inhibitor. Taken together, these data suggest that, although the Rp-NDPalphaB isomer would be minimally phosphorylated by CK or PK, it should not inhibit either enzyme.
Assuntos
Creatina Quinase/antagonistas & inibidores , Fosfatos de Dinucleosídeos/química , Fosfatos de Dinucleosídeos/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Piruvato Quinase/antagonistas & inibidores , Hidrolases Anidrido Ácido/química , Hidrolases Anidrido Ácido/farmacologia , Animais , Creatina Quinase/metabolismo , Cinética , Estrutura Molecular , Fosforilação , Piruvato Quinase/metabolismo , Coelhos , Estereoisomerismo , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
The alpha-P-borano modification, where one of the alpha-phosphate oxygens is replaced by borane, of chain terminating nucleoside triphosphates are currently being tested in cell culture and are showing promise as effective viral polymerase inhibitors. The goal of this project is to combine the alpha-P-borano and Nanogel drug delivery technology to increase the antiviral potency of chain terminating sugar and base modified purine nucleosides versus the Hepatitis C Viral RNA dependent RNA polymerase (HCV RdRp). Here we show the synthesis of Cordycepin and 2'-O-methyl alpha-P-borano triphosphate via a one-pot phosphorochloridite synthesis under mild conditions. These analogues will be used for future structure-activity relationship (SAR) studies.
Assuntos
Trifosfato de Adenosina/análogos & derivados , Antivirais/síntese química , Compostos de Boro/síntese química , Trifosfato de Adenosina/síntese química , Trifosfato de Adenosina/química , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Antivirais/química , Compostos de Boro/química , Hepacivirus/enzimologia , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Nucleotídeos de Timina/síntese química , Nucleotídeos de Timina/químicaRESUMO
This report describes a one-pot synthesis of alpha-P-borano-, alpha-P-thio-, and alpha-P-seleno-modified nucleoside diphosphate analogues that are otherwise difficult to obtain. The key step involves the intramolecular nucleophilic attack by an amino group in 5 to remove the gamma-phosphate. The absolute configurations of P-diastereomers were confirmed by analysis of their 1H NMR. Affinity studies revealed that the nucleoside boranodiphosphates are potentially useful in antiviral research.