4KN6

Crystal structure of human hypoxanthine-guanine phosphoribosyltransferase in complex with 6-fluoro-3-hydroxy-2-pyrazinecarboxamide (T-705) ribose-5'-monophosphate

4KN6 の概要

• エントリーDOI: 10.2210/pdb4kn6/pdb
• 分子名称: Hypoxanthine-guanine phosphoribosyltransferase, 6-fluoro-3-oxo-4-(5-O-phosphono-beta-D-ribofuranosyl)-3,4-dihydropyrazine-2-carboxamide (3 entities in total)
• 機能のキーワード: favipiravir, 6-oxopurine phosphoribosyltransferase, transferase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P00492
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24779.34

構造登録者

Naesens, L.,Guddat, L.,Keough, D.,van Kuilenburg, A.B.P.,Meijer, J.,Vande Voorde, J.,Balzarini, J. (登録日: 2013-05-08, 公開日: 2013-08-14, 最終更新日: 2024-02-28)

主引用文献

Naesens, L.,Guddat, L.W.,Keough, D.T.,van Kuilenburg, A.B.,Meijer, J.,Vande Voorde, J.,Balzarini, J.
Role of human hypoxanthine Guanine phosphoribosyltransferase in activation of the antiviral agent T-705 (favipiravir).
Mol.Pharmacol., 84:615-629, 2013

PubMed Abstract: 6-Fluoro-3-hydroxy-2-pyrazinecarboxamide (T-705) is a novel antiviral compound with broad activity against influenza virus and diverse RNA viruses. Its active metabolite, T-705-ribose-5'-triphosphate (T-705-RTP), is recognized by influenza virus RNA polymerase as a substrate competing with GTP, giving inhibition of viral RNA synthesis and lethal virus mutagenesis. Which enzymes perform the activation of T-705 is unknown. We here demonstrate that human hypoxanthine guanine phosphoribosyltransferase (HGPRT) converts T-705 into its ribose-5'-monophosphate (RMP) prior to formation of T-705-RTP. The anti-influenza virus activity of T-705 and T-1105 (3-hydroxy-2-pyrazinecarboxamide; the analog lacking the 6-fluoro atom) was lost in HGPRT-deficient Madin-Darby canine kidney cells. This HGPRT dependency was confirmed in human embryonic kidney 293T cells undergoing HGPRT-specific gene knockdown followed by influenza virus ribonucleoprotein reconstitution. Knockdown for adenine phosphoribosyltransferase (APRT) or nicotinamide phosphoribosyltransferase did not change the antiviral activity of T-705 and T-1105. Enzymatic assays showed that T-705 and T-1105 are poor substrates for human HGPRT having Km(app) values of 6.4 and 4.1 mM, respectively. Formation of the RMP metabolites by APRT was negligible, and so was the formation of the ribosylated metabolites by human purine nucleoside phosphorylase. Phosphoribosylation and antiviral activity of the 2-pyrazinecarboxamide derivatives was shown to require the presence of the 3-hydroxyl but not the 6-fluoro substituent. The crystal structure of T-705-RMP in complex with human HGPRT showed how this compound binds in the active site. Since conversion of T-705 by HGPRT appears to be inefficient, T-705-RMP prodrugs may be designed to increase the antiviral potency of this new antiviral agent.

PubMed: 23907213
DOI: 10.1124/mol.113.087247

実験手法

X-RAY DIFFRACTION (2.728 Å)