Covalently Targeted Highly Conserved Tyr318 to Improve the Drug Resistance Profiles of HIV-1 NNRTIs: A Proof-of-Concept Study.

This study presents proof of concept for designing a novel HIV-1 covalent inhibitor targeting the highly conserved Tyr318 in the HIV-1 non-nucleoside reverse transcriptase inhibitors binding pocket to improve the drug resistance profiles. The target inhibitor ZA-2 with a fluorosulfate warhead in the structure was found to be a potent inhibitor (EC50 = 11-246 nM) against HIV-1 IIIB and a panel of NNRTIs-resistant strains, being far superior to those of NVP and EFV. Moreover, ZA-2 was demonstrated with lower cytotoxicity (CC50 = 125 µM). In the reverse transcriptase inhibitory assay, ZA-2 exhibited an IC50 value of 0.057 µM with the ELISA method, and the MALDI-TOF MS data demonstrated the covalent binding mode of ZA-2 with the enzyme. Additionally, the molecular simulations have also demonstrated that compounds can form covalent binding to the Tyr318.

Polypyridyl ruthenium complexes as bifunctional TAR RNA binders and HIV-1 reverse transcriptase inhibitors.

Inhibitors of type 1 human immunodeficiency virus (HIV-1) reverse transcriptase are central to anti-HIV therapy. Most of their targets are enzymes, while very few could bind to viral RNA. Here we designed four new polypyridyl Ru(II) complexes, which could bind HIV-1 TAR RNA tightly and selectively by molecular recognition of hydrogen bonds, further stabilize the Ru(II)-RNA bound system by electrostatic attraction, and efficiently inhibit the Moloney murine leukemia virus (M-MuLV) and HIV-1 reverse transcriptase. The polypyridyl Ru(II) complexes also have physical and chemical advantages, including high chemical stability and photostability, sensitive spectroscopic responses to HIV TAR RNA, and low toxicity to normal cells. This work also provides valuable drug design strategies for acquired immune deficiency syndrome (AIDS) and other reverse transcriptase related disease research, such as hepatitis C virus (HCV), Ebola virus (EBOV), influenza A virus, and most recently the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Tenofovir-Amino Acid Conjugates Act as Polymerase Substrates-Implications for Avoiding Cellular Phosphorylation in the Discovery of Nucleotide Analogues.

Nucleotide analogues are used for treating viral infections such as HIV, hepatitis B, hepatitis C, influenza, and SARS-CoV-2. To become polymerase substrates, a nucleotide analogue must be phosphorylated by cellular kinases which is rate-limiting. The goal of this study is to develop dNTP/NTP analogues directly from nucleotides. Tenofovir (TFV) analogues were synthesized by conjugating with amino acids. We demonstrate that some conjugates act as dNTP analogues and HIV-1 reverse transcriptase (RT) catalytically incorporates the TFV part as the chain terminator. X-ray structures in complex with HIV-1 RT/dsDNA showed binding of the conjugates at the polymerase active site, however, in different modes in the presence of Mg2+ versus Mn2+ ions. The adaptability of the compounds is seemingly essential for catalytic incorporation of TFV by RT. 4d with a carboxyl sidechain demonstrated the highest incorporation. 4e showed weak incorporation and rather behaved as a dNTP-competitive inhibitor. This result advocates the feasibility of designing NTP/dNTP analogues by chemical substitutions to nucleotide analogues.