Activation of 6-Alkoxy-Substituted Methylenecyclopropane Nucleoside Analogs Requires Enzymatic Modification by Adenosine Deaminase-Like Protein 1
| Autor: | Brian G. Gentry, Michelle M. Butler, Gloria Komazin-Meredith, Anna C. Burns, John D. Williams, Kathryn J. Vollmer, Steve Cardinale, Islam T. M. Hussein, Zachary D. Aron, Hannah E. Sauer, Terry L. Bowlin, Marc Busch |
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| Rok vydání: | 2019 |
| Předmět: |
Cyclopropanes
Guanine Adenosine Deaminase Cytomegalovirus Herpesvirus 1 Human Virus Replication Antiviral Agents Viral Proteins 03 medical and health sciences chemistry.chemical_compound Adenosine deaminase Chlorocebus aethiops medicine Animals Humans Moiety Pharmacology (medical) Vero Cells Chromatography High Pressure Liquid Polymerase 030304 developmental biology Pharmacology chemistry.chemical_classification 0303 health sciences biology Nucleoside analogue 030306 microbiology Nucleosides Sequence Analysis DNA Adenosine Infectious Diseases Enzyme chemistry Biochemistry DNA Viral Deoxycoformycin biology.protein medicine.drug |
| Zdroj: | Antimicrobial Agents and Chemotherapy. 63 |
| ISSN: | 1098-6596 0066-4804 |
| DOI: | 10.1128/aac.01301-19 |
| Popis: | To determine the mechanism of action of third-generation methylenecyclopropane nucleoside analogs (MCPNAs), DNA sequencing of herpes simplex virus 1 (HSV-1) isolates resistant to third-generation MCPNAs resulted in the discovery of G841S and N815S mutations in HSV-1 UL30. Purified HSV-1 UL30 or human cytomegalovirus (HCMV) UL54 was then subjected to increasing concentrations of MBX-2168-triphosphate (TP), with results demonstrating a 50% inhibitory concentration (IC(50)) of ∼200 μM, indicating that MBX-2168-TP does not inhibit the viral DNA polymerase. Further metabolic studies showed the removal of a moiety on the guanine ring of MBX-2168. Therefore, we hypothesized that enzymatic removal of a moiety at the 6-position of the guanine ring of third-generation MCPNAs is an essential step in activation. To test this hypothesis, pentostatin (deoxycoformycin [dCF]), an adenosine deaminase-like protein 1 (ADAL-1) inhibitor, was coincubated with MBX-2168. The results showed that dCF antagonized the effect of MBX-2168, with a >40-fold increase in the 50% effective concentration (EC(50)) at 50 μM dCF (EC(50) of 63.1 ± 8.7 μM), compared with MBX-2168 alone (EC(50) of 0.2 ± 0.1 μM). Purified ADAL-1 demonstrated time-dependent removal of the moiety on the guanine ring of MBX-2168-monophosphate (MP), with a K(m) of 17.5 ± 2.4 μM and a V(max) of 0.12 ± 0.04 nmol min(−1). Finally, synguanol-TP demonstrated concentration-dependent inhibition of HSV-1 UL30 and HCMV UL54, with IC(50)s of 0.33 ± 0.16 and 0.38 ± 0.11 μM, respectively. We conclude that ADAL-1 is the enzyme responsible for removing the moiety from the guanine ring of MBX-2168-MP prior to conversion to a TP, the active compound that inhibits the viral DNA polymerase. |
| Databáze: | OpenAIRE |
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